1
|
Ghemiș DM, Marcu LG. RTOG 0915-compliant patient specific QA for lung stereotactic body radiotherapy using the new PTW 1600SRS detector array. Phys Med 2024; 127:104822. [PMID: 39368297 DOI: 10.1016/j.ejmp.2024.104822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 09/04/2024] [Accepted: 09/22/2024] [Indexed: 10/07/2024] Open
Abstract
PURPOSE An area of focus in radiotherapy is the treatment of oligometastatic lung cancer using highly conformal techniques such as SBRT, performed using VMAT that involves flattening filter free (FFF) beams. This study proposes a new calibration procedure for PTW Octavius 1600SRS detector array and was designed to also evaluate clinical and dosimetric aspects of a patient-specific quality assurance (PSQA) for lung SBRT patients. METHODS The cohort consists of 20 patients, treated for lung metastases using SBRT with 50 Gy dose in 5 fractions (10 Gy/fr). The proposed calibration method uses only one calibration factor determined at maximum dose rate of 6MV FFF photon beam. The dosimetric accuracy of achieving a high dose gradient was analyzed using the RTOG 0915 protocol and was confirmed by PSQA procedures using the PTW Octavius 1600SRS detector. RESULTS Conformity index, gradient index, maximum dose at 2 cm and V20 parameters were evaluated with clinical favorable results, with only two plans with lesions situated in the inferior lobe exceeding the deviation allowed for the gradient index. Gamma passing rates using the new calibration method were 98.93% and 99.38% for different gamma criteria of 2 mm/2% and 1 mm/3%, respectively. CONCLUSIONS The proposed method for calibration using one calibration factor at maximum dose rate for the involved photon beam shows clinically acceptable gamma passing rates. Employing the RTOG 0915 protocol for lung SBRT treatment plan evaluation brings important dosimetric information about treatment plan quality and dose gradient fall-off which can be correlated with the results achieved during the pretreatment verification procedures.
Collapse
Affiliation(s)
- Diana M Ghemiș
- West University of Timisoara, Faculty of Physics, Timisoara, Romania; MedEuropa, Oradea, Romania.
| | - Loredana G Marcu
- Faculty of Informatics & Science, University of Oradea, Oradea 410087, Romania; UniSA Allied Health and Human Performance, University of South Australia, Adelaide, Australia
| |
Collapse
|
2
|
Jindakan S, Tharavichitkul E, Watcharawipha A, Nobnop W. Improvement of treatment plan quality with modified fixed field volumetric modulated arc therapy in cervical cancer. J Appl Clin Med Phys 2024; 25:e14479. [PMID: 39032169 PMCID: PMC11466474 DOI: 10.1002/acm2.14479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/23/2024] [Accepted: 07/07/2024] [Indexed: 07/22/2024] Open
Abstract
PURPOSE This study aims to introduce modified fixed field volumetric modulated arc therapy (MF-VMAT) which manually opened the field size by fixing the jaws and comparing it to the typical planning technique, auto field volumetric modulated arc therapy (AF-VMAT) in cervical cancer treatment planning. METHODS AND MATERIALS Previously treated twenty-eight cervical cancer plans were retrospectively randomly selected and replanned in this study using two different planning techniques: AF-VMAT and MF-VMAT, resulting in a total of fifty-six treatment plans. In this study, we compared both planning techniques in three parts: (1) Organ at Risk (OARs) and whole-body dose, (2) Treatment plan efficiency, and (3) Treatment plan accuracy. RESULTS For OARs dose, bowel bag (p-value = 0.001), rectum (p-value = 0.002), and left femoral head (p-value = 0.001) and whole-body (p-value = 0.000) received a statistically significant dose reduction when using the MF-VMAT plan. Regarding plan efficiency, MF-VMAT exhibited a statistically significant increase in both number of monitor units (MUs) and control points (p-values = 0.000), while beam-on time, maximum leaf travel, average maximum leaf travel, and maximum leaf travel per gantry rotation were statistically significant decreased (p-values = 0.000). In terms of plan accuracy, the average gamma passing rate was higher in the MF-VMAT plan for both absolute dose (AD) (p-value = 0.001, 0.004) and relative dose (RD) (p-value = 0.000, 0.000) for 3%/3 and 3%/2 mm gamma criteria, respectively. CONCLUSION The MF-VMAT planning technique significantly reduces OAR doses and decreases the spread of low doses to normal tissues in cervical cancer patients. Additionally, this planning approach demonstrates efficient plans with lower beam-on time and reduced maximum leaf travel. Furthermore, it indicates higher plan accuracy through an increase in the average gamma passing rate compared to the AF-VMAT plan. Consequently, MF-VMAT offers an effective treatment planning technique for cervical cancer patients.
Collapse
Affiliation(s)
- Sirawat Jindakan
- Medical Physics ProgramDepartment of RadiologyFaculty of MedicineChiang Mai UniversityChiang MaiThailand
| | - Ekkasit Tharavichitkul
- Department of RadiologyFaculty of MedicineThe Division of Radiation OncologyChiang Mai UniversityChiang MaiThailand
| | - Anirut Watcharawipha
- Department of RadiologyFaculty of MedicineThe Division of Radiation OncologyChiang Mai UniversityChiang MaiThailand
| | - Wannapha Nobnop
- Department of RadiologyFaculty of MedicineThe Division of Radiation OncologyChiang Mai UniversityChiang MaiThailand
| |
Collapse
|
3
|
Piotrowski T, Ryczkowski A, Kalendralis P, Adamczewski M, Sadowski P, Bajon B, Kruszyna-Mochalska M, Jodda A. Forecasting model for qualitative prediction of the results of patient-specific quality assurance based on planning and complexity metrics and their interrelations. Pilot study. Rep Pract Oncol Radiother 2024; 29:318-328. [PMID: 39144260 PMCID: PMC11321782 DOI: 10.5603/rpor.101093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 05/31/2024] [Indexed: 08/16/2024] Open
Abstract
Background The purpose was to analyse the interrelations between planning and complexity metrics and gamma passing rates (GPRs) obtained from VMAT treatments and build the forecasting models for qualitative prediction (QD) of GPRs results. Materials and method 802 treatment arcs from the plans prepared for the head and neck, thorax, abdomen, and pelvic cancers were analysed. The plans were verified by portal dosimetry and analysed twice using the gamma method with 3%|2mm and 2%|2mm acceptance criteria. The tolerance limit of GPR was 95%. Red, yellow, and green QDs were established for GPR examination. The interrelations were examined, as well as the analysis of effective differentiation of QD. Three models for QD forecasting based on discriminant analysis (DA), random decision forest (RDF) methods, and the hybrid model (HM) were built and evaluated. Results Most of the interrelations were small or moderate. The exception is correlations of the join function with the average number of monitor units per control point (R = 0.893) and the beam aperture with planning target volume (R = 0.897). While many metrics allow for the effective separation of the QDs from each other, the study shows that predicting the values of the QD is possible only through multi-component forecasting models, of which the HM is the most accurate (0.894). Conclusion Of the three models explored in this study, the HM, which uses DA methods to predict red QD and RDF methods to predict green and yellow QDs, is the most promising one.
Collapse
Affiliation(s)
- Tomasz Piotrowski
- Department of Electroradiology, Poznan University of Medical Sciences, Poznan, Poland
- Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland
- Department of Biomedical Physics, Adam Mickiewicz University, Poznan, Poland
| | - Adam Ryczkowski
- Department of Electroradiology, Poznan University of Medical Sciences, Poznan, Poland
- Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland
| | - Petros Kalendralis
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Marcin Adamczewski
- Department of Biomedical Physics, Adam Mickiewicz University, Poznan, Poland
| | - Piotr Sadowski
- Department of Electroradiology, Poznan University of Medical Sciences, Poznan, Poland
| | - Barbara Bajon
- Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland
| | - Marta Kruszyna-Mochalska
- Department of Electroradiology, Poznan University of Medical Sciences, Poznan, Poland
- Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland
| | - Agata Jodda
- Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland
| |
Collapse
|
4
|
Zhou Y, Liu Y, Chen M, Fang J, Xiao L, Huang S, Qi Z, Deng X, Zhang J, Peng Y. Commissioning and clinical evaluation of a novel high-resolution quality assurance digital detector array for SRS and SBRT. J Appl Clin Med Phys 2024; 25:e14258. [PMID: 38175960 PMCID: PMC11005972 DOI: 10.1002/acm2.14258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 12/03/2023] [Accepted: 12/18/2023] [Indexed: 01/06/2024] Open
Abstract
PURPOSE We aimed to perform the commissioning and clinical evaluation of myQA SRS detector array for patient-specific quality assurance (PSQA) of stereotactic radiosurgery (SRS)/ stereotactic body radiotherapy (SBRT) plans. METHODS To perform the commissioning of myQA SRS, its dose linearity, dose-rate dependence, angular dependence, and field-size dependence were investigated. Ten SBRT plans were selected for clinical evaluation: 1) Common clinical deviations based on the original SBRT plan (Plan0), including multileaf collimator (MLC) positioning deviation and treatment positioning deviation were introduced. 2) Compared the performance of the myQA SRS and a high-resolution EPID dosimetry system in PSQA measurement for the SBRT plans. Evaluation parameters include gamma passing rate (GPR) and distance-to-agreement (DTA) pass rate (DPR). RESULTS The dose linearity, angle dependence, and field-size dependence of myQA SRS system exhibit excellent performance. The myQA SRS is highly sensitive in the detection of MLC deviations. The GPR of (3%/1 mm) decreases from 90.4% of the original plan to 72.7%/62.9% with an MLC outward/inward deviation of 3 mm. Additionally, when the setup error deviates by 1 mm in the X, Y, and Z directions with the GPR of (3%/1 mm) decreasing by an average of -20.9%, -25.7%, and -24.7%, respectively, and DPR (1 mm) decreasing by an average of -33.7%, -32.9%, and -29.8%. Additionally, the myQA SRS has a slightly higher GPR than EPID for PSQA, However, the difference is not statistically significant with the GPR of (3%/1 mm) of (average 90.4%% vs. 90.1%, p = 0.414). CONCLUSION Dosimetry characteristics of the myQA SRS device meets the accuracy and sensitivity requirement of PSQA for SRS/SBRT treatment. The dose rate dependence should be adequately calibrated before its application and a more stringent GPR (3%/1 mm) evaluation criterion is suggested when it is used for SRS/SBRT QA.
Collapse
Affiliation(s)
- Yang Zhou
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
- Department of Radiation Oncology, Zhuzhou Hospital Affiliated to Xiangya School of MedicineCentral South UniversityZhuzhouP. R. China
| | - Yimei Liu
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
| | - Meining Chen
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
| | - Jianlan Fang
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
| | - Liangjie Xiao
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
| | - Shaomin Huang
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
| | - Zhenyu Qi
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
| | - Xiaowu Deng
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
| | - Jun Zhang
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
| | - Yinglin Peng
- State Key Laboratory of Oncology in South China, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangdong Provincial Clinical Research Center for CancerSun Yat‐sen University Cancer CenterGuangzhouP. R. China
| |
Collapse
|
5
|
Zhang H, Zhang B, Lasio G, Chen S, Nasehi Tehrani J. Assessing quality assurance of multi-leaf collimator using the structural similarity index. J Appl Clin Med Phys 2024; 25:e14288. [PMID: 38345201 PMCID: PMC11005984 DOI: 10.1002/acm2.14288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 12/11/2023] [Accepted: 01/22/2024] [Indexed: 04/11/2024] Open
Abstract
PURPOSE This study aims to evaluate the viability of utilizing the Structural Similarity Index (SSI*) as an innovative imaging metric for quality assurance (QA) of the multi-leaf collimator (MLC). Additionally, we compared the results obtained through SSI* with those derived from a conventional Gamma index test for three types of Varian machines (Trilogy, Truebeam, and Edge) over a 12-week period of MLC QA in our clinic. METHOD To assess sensitivity to MLC positioning errors, we designed a 1 cm slit on the reference MLC, subsequently shifted by 0.5-5 mm on the target MLC. For evaluating sensitivity to output error, we irradiated five 25 cm × 25 cm open fields on the portal image with varying Monitor Units (MUs) of 96-100. We compared SSI* and Gamma index tests using three linear accelerator (LINAC) machines: Varian Trilogy, Truebeam, and Edge, with MLC leaf widths of 1, 0.5, and 0.25 mm. Weekly QA included VMAT and static field modes, with Picket fence test images acquired. Mechanical uncertainties related to the LINAC head, electronic portal imaging device (EPID), and MLC during gantry rotation and leaf motion were monitored. RESULTS The Gamma index test started detecting the MLC shift at a threshold of 4 mm, whereas the SSI* metric showed sensitivity to shifts as small as 2 mm. Moreover, the Gamma index test identified dose changes at 95MUs, indicating a 5% dose difference based on the distance to agreement (DTA)/dose difference (DD) criteria of 1 mm/3%. In contrast, the SSI* metric alerted to dose differences starting from 97MUs, corresponding to a 3% dose difference. The Gamma index test passed all measurements conducted on each machine. However, the SSI* metric rejected all measurements from the Edge and Trilogy machines and two from the Truebeam. CONCLUSIONS Our findings demonstrate that the SSI* exhibits greater sensitivity than the Gamma index test in detecting MLC positioning errors and dose changes between static and VMAT modes. The SSI* metric outperformed the Gamma index test regarding sensitivity across these parameters.
Collapse
Affiliation(s)
- Hong Zhang
- Departments of Radiation OncologyVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Baoshe Zhang
- Departments of Radiation OncologyMedical SchoolUniversity of MarylandBaltimoreMarylandUSA
| | - Giovanni Lasio
- Departments of Radiation OncologyMedical SchoolUniversity of MarylandBaltimoreMarylandUSA
| | - Shifeng Chen
- Departments of Radiation OncologyMedical SchoolUniversity of MarylandBaltimoreMarylandUSA
| | - Joubin Nasehi Tehrani
- Departments of Radiation OncologyMedical SchoolUniversity of MarylandBaltimoreMarylandUSA
| |
Collapse
|
6
|
Kamal R, Thaper D, Singh G, Sharma S, Navjeet, Oinam AS, Kumar V. Modeling of Gamma Index for Prediction of Pretreatment Quality Assurance in Stereotactic Body Radiation Therapy of the Liver. J Med Phys 2024; 49:232-239. [PMID: 39131435 PMCID: PMC11309143 DOI: 10.4103/jmp.jmp_176_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/29/2024] [Accepted: 04/09/2024] [Indexed: 08/13/2024] Open
Abstract
Purpose The purpose of this study was to develop a predictive model to evaluate pretreatment patient-specific quality assurance (QA) based on treatment planning parameters for stereotactic body radiation therapy (SBRT) for liver carcinoma. Materials and Methods We retrospectively selected 180 cases of liver SBRT treated using the volumetric modulated arc therapy technique. Numerous parameters defining the plan complexity were calculated from the DICOM-RP (Radiotherapy Plan) file using an in-house program developed in MATLAB. Patient-specific QA was performed with global gamma evaluation criteria of 2%/2 mm and 3%/3 mm in a relative mode using the Octavius two-dimensional detector array. Various statistical tests and multivariate predictive models were evaluated. Results The leaf speed (MILS) and planning target volume size showed the highest correlation with the gamma criteria of 2%/2 mm and 3%/3 mm (P < 0.05). Degree of modulation (DoM), MCSSPORT, leaf speed (MILS), and gantry speed (MIGS) were predictors of global gamma pass rate (GPR) for 2%/2 mm (G22), whereas DoM, MCSSPORT, leaf speed (MILS) and robust decision making were predictors of the global GPR criterion of 3%/3 mm (G33). The variance inflation factor values of all predictors were <2, indicating that the data were not associated with each other. For the G22 prediction, the sensitivity and specificity of the model were 75.0% and 75.0%, respectively, whereas, for G33 prediction, the sensitivity and specificity of the model were 74.9% and 85.7%%, respectively. Conclusions The model was potentially beneficial as an easy alternative to pretreatment QA in predicting the uncertainty in plan deliverability at the planning stage and could help reduce resources in busy clinics.
Collapse
Affiliation(s)
- Rose Kamal
- Department of Radiation Oncology, Amrita Institute of Medical Sciences and Research Centre, Faridabad, Haryana, India
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Deepak Thaper
- Department of Radiation Oncology, Amrita Institute of Medical Sciences and Research Centre, Faridabad, Haryana, India
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Gaganpreet Singh
- Department of Medical Physics, Apollo Proton Cancer Centre, Chennai, Tamil Nadu, India
| | - Shambhavi Sharma
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Navjeet
- Department of Radiation Oncology, Amrita Institute of Medical Sciences and Research Centre, Faridabad, Haryana, India
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Arun Singh Oinam
- Department of Radiotherapy, Post Graduate Institute of Medical Education and Research, Regional Cancer Centre, Chandigarh, India
| | - Vivek Kumar
- Centre for Medical Physics, Panjab University, Chandigarh, India
| |
Collapse
|
7
|
Alzahrani HM. The impact of sinusitis on dose distribution in a radiotherapy plan by in silico study. Saudi Med J 2024; 45:235-240. [PMID: 38438210 PMCID: PMC11115391 DOI: 10.15537/smj.2024.45.3.20230520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 01/07/2024] [Indexed: 03/06/2024] Open
Abstract
OBJECTIVES To assess the impact of changes in sinus aeration on dose variation in nasopharyngeal cases using a single beam with various field sizes and real patient computed tomography (CT) images. METHODS The calculations were carried out on a computer equipped with an Intel Xeon (R) Gold 5118 processor operating at 2.30 GHz in 2022 at Taibah University, Al Madinah Al Munawwarah for a retrospective nasopharyngeal case. At the patient level, the impact on dose distribution was examined for different field sizes by comparing the percentage depth dose. The dose discrepancy was evaluated by comparing the dose delivered without considering the anatomical changes observed in the initial fraction to the dose adjusted to account for these changes using a 2D gamma analysis. With a criterion of 1% dose difference and 1 mm distance to agreement, the gamma level for analysis was set at 95%. RESULTS The study findings indicated that the observed effect diminished by approximately 50% for both 5 cm x 5 cm and 10 cm x 10 cm field sizes compared to the 3 cm x 3 cm size, where there was an overlap between the planning target volume and sinusitis. CONCLUSION The study concluded that the impact of dose discrepancy was more pronounced in smaller field sizes.
Collapse
Affiliation(s)
- Hanan M. Alzahrani
- From the Department of Radiology Technology, College of Applied Medical Sciences, Taibah University, Al Madinah Al Munawwarah, Kingdom of Saudi Arabia.
| |
Collapse
|
8
|
Tozuka R, Kadoya N, Tomori S, Kimura Y, Kajikawa T, Sugai Y, Xiao Y, Jingu K. Improvement of deep learning prediction model in patient-specific QA for VMAT with MLC leaf position map and patient's dose distribution. J Appl Clin Med Phys 2023; 24:e14055. [PMID: 37261720 PMCID: PMC10562023 DOI: 10.1002/acm2.14055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 04/21/2023] [Accepted: 05/13/2023] [Indexed: 06/02/2023] Open
Abstract
PURPOSE Deep learning-based virtual patient-specific quality assurance (QA) is a novel technique that enables patient QA without measurement. However, this method could be improved by further evaluating the optimal data to be used as input. Therefore, a deep learning-based model that uses multileaf collimator (MLC) information per control point and dose distribution in patient's CT as inputs was developed. METHODS Overall, 96 volumetric-modulated arc therapy plans generated for prostate cancer treatment were used. We developed a model (Model 1) that can predict measurement-based gamma passing rate (GPR) for a treatment plan using data stored as a map reflecting the MLC leaf position at each control point (MLPM) and data of the dose distribution in patient's CT as inputs. The evaluation of the model was based on the mean absolute error (MAE) and Pearson's correlation coefficient (r) between the measured and predicted GPR. For comparison, we also analyzed models trained with the dose distribution in patient's CT alone (Model 2) and with dose distributions recalculated on a virtual phantom CT (Model 3). RESULTS At the 2%/2 mm criterion, MAE[%] and r for Model 1, Model 2, and Model 3 were 2.32% ± 0.43% and 0.54 ± 0.03, 2.70% ± 0.26%, and 0.32 ± 0.08, and 2.96% ± 0.23% and 0.24 ± 0.22, respectively; at the 3%/3 mm criterion, these values were 1.25% ± 0.05% and 0.36 ± 0.18, 1.57% ± 0.35% and 0.19 ± 0.20, and 1.39% ± 0.32% and 0.17 ± 0.22, respectively. This result showed that Model 1 exhibited the lowest MAE and highest r at both criteria of 2%/2 mm and 3%3 mm. CONCLUSIONS These findings showed that a model that combines the MLPM and dose distribution in patient's CT exhibited a better GPR prediction performance compared with the other two studied models.
Collapse
Affiliation(s)
- Ryota Tozuka
- Department of Radiation OncologyTohoku University Graduate School of MedicineSendaiMiyagiJapan
| | - Noriyuki Kadoya
- Department of Radiation OncologyTohoku University Graduate School of MedicineSendaiMiyagiJapan
| | - Seiji Tomori
- Department of RadiologyNational Hospital Organization Sendai Medical CenterSendaiMiyagiJapan
| | - Yuto Kimura
- Radiation Oncology CenterOfuna Chuo HospitalKamakuraJapan
| | - Tomohiro Kajikawa
- Department of Radiation OncologyTohoku University Graduate School of MedicineSendaiMiyagiJapan
- Department of Radiology, Graduate School of Medical ScienceKyoto Prefectural University of MedicineKyotoJapan
| | - Yuto Sugai
- Department of Radiological TechnologyKeio University Hospital, ShinjukuJapan
| | - Yushan Xiao
- Department of Radiation OncologyTohoku University Graduate School of MedicineSendaiMiyagiJapan
| | - Keiichi Jingu
- Department of Radiation OncologyTohoku University Graduate School of MedicineSendaiMiyagiJapan
| |
Collapse
|
9
|
Electronic Portal Imaging Device in Pre-Treatment Patient-Specific Quality Assurance of volumetric-modulated arc therapy delivery. JOURNAL OF RADIOTHERAPY IN PRACTICE 2023. [DOI: 10.1017/s1460396922000334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Abstract
Background:
Radiotherapy treatment delivery is evaluated by a pre-treatment patient-specific quality assurance (PSQA) procedure to ensure the patient receives an accurate radiation dose. The current PSQA practice by using conventional phantoms requires more set-up time and cost of purchasing the tools. Therefore, this study aimed to investigate the efficiency of an electronic portal imaging device (EPID) of linear accelerator (LINAC) as a PSQA tool for volumetric-modulated arc therapy (VMAT) planning technique for nasopharyngeal carcinoma (NPC) treatment delivery.
Methods:
A NPC VMAT plan on a Rando phantom was performed by following the Radiation Therapy Oncology Group (RTOG) 0615 protocol. The gamma passing rate of the EPID and PSQA phantom (ArcCHECK) were compared among the gamma criteria of 3%/3 mm, 2%/2 mm and 1%/1 mm, respectively.
Results:
Both EPID and ArcCHECK phantom had distinguishable gamma passing rates in 3%/3 mm and 2%/2 mm with a difference of 0·87% and 0·30%, respectively. Meanwhile, the EPID system had a lower gamma passing rate than the ArcCHECK phantom in 1%/1 mm (21·23% difference). Furthermore, the sensitivity of the EPID system was evaluated and had the largest deviation in gamma passing rate from the reference position in gamma criteria of 2%/2 mm (41·14%) compared to the 3%/3 mm (25·45%) and 1%/1 mm (31·78%), discretely. The best fit line of the linear regression model for EPID was steeper than the ArcCHECK phantom in 3%/3 mm and 2%/2 mm, and vice versa in gamma criteria of 1%/1 mm. This indicates that the EPID had a higher sensitivity than the ArcCHECK phantom in 3%/3 mm and 2%/2 mm but less sensitivity in 1%/1 mm.
Conclusions:
The EPID system was efficient in performing the PSQA test of VMAT treatment in HUSM with the gamma criteria of 3%/3 mm and 2%/2 mm.
Collapse
|
10
|
Price RA, Veltchev I, Lin T, Eldib A, Chen L, Jin L, Chen X, Liu J, Wang L, Ma CMC. Evaluating suggested stricter gamma criteria for linac-based patient-specific delivery QA in the conventional and SBRT environments. Phys Med 2022; 100:72-80. [PMID: 35759942 DOI: 10.1016/j.ejmp.2022.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 06/01/2022] [Accepted: 06/11/2022] [Indexed: 10/17/2022] Open
Abstract
PURPOSE To evaluate AAPM TG-218 recommended tolerances for IMRT QA for conventional and SBRT delivery. METHODS QA analysis was repeated for 150 IMRT/VMAT patients with varying gamma criteria. True composite delivery was utilized, corrected for detector and output variation. Universal tolerance (TLuniv) and action limits (ALuniv) were compared with statistical process control (SPC) TLSPC and ALSPC values. Analysis was repeated as a function of plan complexity for 250 non-stereotactic body radiotherapy (SBRT) VMAT patients at 3%/2mm and a threshold of 10% and for 75 SBRT VMAT patients at 2%/2 mm and a threshold of 50% with results plotted as a function of PTV volume. Regions of failure were dose-scaled on the planning CT data sets based on delivery results. RESULTS The IMRT/VMAT TLSPC and ALSPC for gamma criteria of 3%/3 mm were 96.5% and 95.6% and for 3%/2 mm were 91.2% and 89.2%, respectively. Correlation with plan complexity for conventional fractionation VMAT was "low" for all sites with pelvis having the highest r value at -0.35. The equivalent SBRT PTV diameter ranged from 2.0 cm to 5.6 cm. Negative low correlation was found for 38 of 75 VMAT cases below ALuniv. CONCLUSIONS The ALuniv and ALSPC are similar for 3%/2 mm. However, our 5% failure rate for ALuniv, may result in treatment start delays approximately 2 times/month, given 40 new cases/month. VMAT QA failure at stricter criteria did not correlate strongly with plan complexity. Site-specific action limits vary less than 3% from the average. SBRT QA results do not strongly correlate with target size over the range studied.
Collapse
Affiliation(s)
- Robert A Price
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States.
| | - Iavor Veltchev
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States
| | - Teh Lin
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States
| | - Ahmed Eldib
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States
| | - Lili Chen
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States
| | - Lihui Jin
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States
| | - Xiaoming Chen
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States
| | - Jie Liu
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States
| | - Lu Wang
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States
| | - C-M Charlie Ma
- Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Avenue, Philadelphia, PA 19111, United States
| |
Collapse
|
11
|
Bismack B, Dolan J, Laugeman E, Gopal A, Wen N, Chetty I. Model refinement increases confidence levels and clinical agreement when commissioning a three-dimensional secondary dose calculation system. J Appl Clin Med Phys 2022; 23:e13590. [PMID: 35389554 PMCID: PMC9194992 DOI: 10.1002/acm2.13590] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 01/13/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022] Open
Abstract
Purpose Evaluate custom beam models for a second check dose calculation system using statistically verifiable passing criteria for film analysis, DVH, and 3D gamma metrics. Methods Custom beam models for nine linear accelerators for the Sun Nuclear Dose Calculator algorithm (SDC, Sun Nuclear) were evaluated using the AAPM‐TG119 test suite (5 Intensity Modulated Radiation Therapy (IMRT) and 5 Volumetric Modulated Arc Therapy (VMAT) plans) and a set of clinical plans. Where deemed necessary, adjustments to Multileaf Collimator (MLC) parameters were made to improve results. Comparisons to the Analytic Anisotropic Algorithm (AAA), and gafchromic film measurements were performed. Confidence intervals were set to 95% per TG‐119. Film gamma criteria were 3%/3 mm (conventional beams) or 3%/1 mm (Stereotactic Radiosurgery [SRS] beams). Dose distributions in solid water phantom were evaluated based on DVH metrics (e.g., D95, V20) and 3D gamma criteria (3%/3 mm or 3%/1 mm). Film passing rates, 3D gamma passing rates, and DVH metrics were reported for HD MLC machines and Millennium MLC Machines. Results For HD MLC machines, SDC gamma film agreement was 98.76% ± 2.30% (5.74% CL) for 6FFF/6srs (3%/1 mm), and 99.80% ± 0.32% (0.83% CL) for 6x (3%/3 mm). For Millennium MLC machines, film passing rates were 98.20% ± 3.14% (7.96% CL), 99.52% ± 1.14% (2.71% CL), and 99.69% ± 0.82% (1.91% CL) for 6FFF, 6x, and 10x, respectively. For SDC to AAA comparisons: HD MLC Linear Accelerators (LINACs); DVH point agreement was 0.97% ± 1.64% (4.18% CL) and 1.05% ± 2.12% (5.20% CL); 3D gamma agreement was 99.97% ± 0.14% (0.30% CL) and 100.00% ± 0.02% (0.05% CL), for 6FFF/6srs and 6x, respectively; Millennium MLC LINACs: DVH point agreement was 0.77% ± 2.40% (5.47% CL), 0.80% ± 3.40% (7.47% CL), and 0.07% ± 2.15% (4.30% CL); 3D gamma agreement was 99.97% ± 0.13% (0.29% CL), 99.97% ± 0.17% (0.36% CL), and 99.99% ± 0.06% (0.12% CL) for 6FFF, 6x, and 10x, respectively. Conclusion SDC shows agreement well within TG119 CLs for film and redundant dose calculation comparisons with AAA. In some models (SRS), this was achieved using stricter criteria. TG119 plans can be used to help guide model adjustments and to establish clinical baselines for DVH and 3D gamma criteria.
Collapse
Affiliation(s)
| | | | | | - Anant Gopal
- Henry Ford Health System, Detroit, Michigan, USA
| | - Ning Wen
- Henry Ford Health System, Detroit, Michigan, USA
| | | |
Collapse
|
12
|
Gray A, Bawazeer O, Arumugam S, Vial P, Descallar J, Thwaites D, Holloway L. Evaluation of the ability of three commercially available dosimeters to detect systematic delivery errors in step-and-shoot IMRT plans. Rep Pract Oncol Radiother 2021; 26:793-803. [PMID: 34760314 DOI: 10.5603/rpor.a2021.0093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 07/03/2021] [Indexed: 11/25/2022] Open
Abstract
Background There is limited data on error detectability for step-and-shoot intensity modulated radiotherapy (sIMRT) plans, despite significant work on dynamic methods. However, sIMRT treatments have an ongoing role in clinical practice. This study aimed to evaluate variations in the sensitivity of three patient-specific quality assurance (QA) devices to systematic delivery errors in sIMRT plans. Materials and methods Four clinical sIMRT plans (prostate and head and neck) were edited to introduce errors in: Multi-Leaf Collimator (MLC) position (increasing field size, leaf pairs offset (1-3 mm) in opposite directions; and field shift, all leaves offset (1-3 mm) in one direction); collimator rotation (1-3 degrees) and gantry rotation (0.5-2 degrees). The total dose for each plan was measured using an ArcCHECK diode array. Each field, excluding those with gantry offsets, was also measured using an Electronic Portal Imager and a MatriXX Evolution 2D ionisation chamber array. 132 plans (858 fields) were delivered, producing 572 measured dose distributions. Measured doses were compared to calculated doses for the no-error plan using Gamma analysis with 3%/3 mm, 3%/2 mm, and 2%/2 mm criteria (1716 analyses). Results Generally, pass rates decreased with increasing errors and/or stricter gamma criteria. Pass rate variations with detector and plan type were also observed. For a 3%/3 mm gamma criteria, none of the devices could reliably detect 1 mm MLC position errors or 1 degree collimator rotation errors. Conclusions This work has highlighted the need to adapt QA based on treatment plan type and the need for detector specific assessment criteria to detect clinically significant errors.
Collapse
Affiliation(s)
- Alison Gray
- Liverpool and Macarthur Cancer Therapy Centres, South Western Sydney Local Health District, Sydney, NSW, Australia.,Ingham Institute for Applied Medical Research, Sydney, NSW, Australia.,South Western Sydney Clinical School, School of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Omemh Bawazeer
- Physics Department, Umm Al-Qura University, Mecca, Saudi Arabia
| | - Sankar Arumugam
- Liverpool and Macarthur Cancer Therapy Centres, South Western Sydney Local Health District, Sydney, NSW, Australia.,Ingham Institute for Applied Medical Research, Sydney, NSW, Australia.,South Western Sydney Clinical School, School of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Philip Vial
- Liverpool and Macarthur Cancer Therapy Centres, South Western Sydney Local Health District, Sydney, NSW, Australia.,Ingham Institute for Applied Medical Research, Sydney, NSW, Australia.,South Western Sydney Clinical School, School of Medicine, University of New South Wales, Sydney, NSW, Australia.,Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia
| | - Joseph Descallar
- Ingham Institute for Applied Medical Research, Sydney, NSW, Australia.,South Western Sydney Clinical School, School of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - David Thwaites
- Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia
| | - Lois Holloway
- Liverpool and Macarthur Cancer Therapy Centres, South Western Sydney Local Health District, Sydney, NSW, Australia.,Ingham Institute for Applied Medical Research, Sydney, NSW, Australia.,South Western Sydney Clinical School, School of Medicine, University of New South Wales, Sydney, NSW, Australia.,Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| |
Collapse
|
13
|
Chen A, Zhu J, Wang N, Chen L, Chen L. Comparison of three-dimensional patient-specific dosimetry systems with delivery errors: Toward a new synchronous measurement method. Phys Med 2021; 90:134-141. [PMID: 34644660 DOI: 10.1016/j.ejmp.2021.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/13/2021] [Accepted: 09/23/2021] [Indexed: 01/13/2023] Open
Abstract
PURPOSE This study proposed a synchronous measurement method for patient-specific dosimetry using two three-dimensional dose verification systems with delivery errors. METHODS Twenty hypofractionated radiotherapy treatment plans for patients with lung cancer were retrospectively reviewed. Monitor unit (MU) changes, leaf in-position errors, and angles of deviation of the collimator were intentionally introduced to investigate the detection sensitivity of the EDose + EPID (EE) and Dolphin + Compass (DC) systems. RESULTS Both systems accurately detected the MU modifications and had a similar ability to detect leaf in-position errors. The detection of multi-leaf collimator (MLC) errors was difficult for the whole body using different gamma criteria. When the introduced MLC error was 1.0 mm, the numbers of errors detected in the clinical target volume (CTV) by the EE system were 20, 20, and 20 and the numbers of errors detected by the DC system were 18, 19, and 20, at 3%/2 mm, 2%/2 mm, and 1%/1 mm, respectively. The average dose deviation of all DVH parameters exceeded 3%. The gamma and DVH evaluation results remained unchanged for the DC system when different collimator angle errors were introduced. The number of errors detected by the EE system was <11 for each anatomical structure for all gamma criteria. The mean dose deviation of the CTV was not distinguished. CONCLUSIONS This synchronous measurement approach can effectively eliminate the influence of random errors during treatment. The EE and DC systems reconstruct the three-dimensional dose distribution accurately and are convenient and reliable for dose verification.
Collapse
Affiliation(s)
- Along Chen
- Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, NO. 651 Dongfeng Road, Guangzhou 510060, China
| | - Jinhan Zhu
- Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, NO. 651 Dongfeng Road, Guangzhou 510060, China
| | - Ning Wang
- Department of Radiotherapy, Zhongshan Affiliated Hospital, Guangzhou University of Chinese Medicine, NO. 3 Kangxin Road West District, Zhongshan 528401, China
| | - Li Chen
- Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, NO. 651 Dongfeng Road, Guangzhou 510060, China
| | - Lixin Chen
- Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, NO. 651 Dongfeng Road, Guangzhou 510060, China.
| |
Collapse
|
14
|
Dai G, Zhang X, Liu W, Li Z, Wang G, Liu Y, Xiao Q, Duan L, Li J, Song X, Li G, Bai S. Analysis of EPID Transmission Fluence Maps Using Machine Learning Models and CNN for Identifying Position Errors in the Treatment of GO Patients. Front Oncol 2021; 11:721591. [PMID: 34595115 PMCID: PMC8476908 DOI: 10.3389/fonc.2021.721591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/30/2021] [Indexed: 02/05/2023] Open
Abstract
Purpose To find a suitable method for analyzing electronic portal imaging device (EPID) transmission fluence maps for the identification of position errors in the in vivo dose monitoring of patients with Graves' ophthalmopathy (GO). Methods Position errors combining 0-, 2-, and 4-mm errors in the left-right (LR), anterior-posterior (AP), and superior-inferior (SI) directions in the delivery of 40 GO patient radiotherapy plans to a human head phantom were simulated and EPID transmission fluence maps were acquired. Dose difference (DD) and structural similarity (SSIM) maps were calculated to quantify changes in the fluence maps. Three types of machine learning (ML) models that utilize radiomics features of the DD maps (ML 1 models), features of the SSIM maps (ML 2 models), and features of both DD and SSIM maps (ML 3 models) as inputs were used to perform three types of position error classification, namely a binary classification of the isocenter error (type 1), three binary classifications of LR, SI, and AP direction errors (type 2), and an eight-element classification of the combined LR, SI, and AP direction errors (type 3). Convolutional neural network (CNN) was also used to classify position errors using the DD and SSIM maps as input. Results The best-performing ML 1 model was XGBoost, which achieved accuracies of 0.889, 0.755, 0.778, 0.833, and 0.532 in the type 1, type 2-LR, type 2-AP, type 2-SI, and type 3 classification, respectively. The best ML 2 model was XGBoost, which achieved accuracies of 0.856, 0.731, 0.736, 0.949, and 0.491, respectively. The best ML 3 model was linear discriminant classifier (LDC), which achieved accuracies of 0.903, 0.792, 0.870, 0.931, and 0.671, respectively. The CNN achieved classification accuracies of 0.925, 0.833, 0.875, 0.949, and 0.689, respectively. Conclusion ML models and CNN using combined DD and SSIM maps can analyze EPID transmission fluence maps to identify position errors in the treatment of GO patients. Further studies with large sample sizes are needed to improve the accuracy of CNN.
Collapse
Affiliation(s)
- Guyu Dai
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xiangbin Zhang
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Wenjie Liu
- Machine Intelligence Laboratory, College of Computer Science, Sichuan University, Chengdu, China
| | - Zhibin Li
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Guangyu Wang
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yaxin Liu
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Qing Xiao
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Lian Duan
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Jing Li
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Xinyu Song
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Guangjun Li
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Sen Bai
- Department of Radiation Oncology, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
15
|
Retrospective analysis of portal dosimetry pre-treatment quality assurance of intracranial SRS/SRT VMAT treatment plans. JOURNAL OF RADIOTHERAPY IN PRACTICE 2021. [DOI: 10.1017/s146039692100042x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background:
The complexity associated with the treatment planning and delivery of stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) volumetric modulated arc therapy (VMAT) plans which employs continuous dynamic modulation of dose rate, field aperture and gantry speed necessitates diligent pre-treatment patient-specific quality assurance (QA). Numerous techniques for pre-treatment VMAT treatment plans QA are currently available with the aid of several different devices including the electronic portal imager (EPID). Although several studies have provided recommendations for gamma criteria for VMAT pre-treatment QA, there are no specifics for SRS/SRT VMAT QA. Thus, we conducted a study to evaluate intracranial SRS/SRT VMAT QA to determine clinical action levels for gamma criteria based on the institutional estimated means and standard deviations.
Materials and methods:
We conducted a retrospective analysis of 118 EPID patient-specific pre-treatment QA dosimetric measurements of 47 brain SRS/SRT VMAT treatment plans using the integrated Varian solution (RapidArcTM planning, EPID and Portal dosimetry system) for planning, delivery and EPID QA analysis. We evaluated the maximum gamma (γmax), average gamma (γave) and percentage gamma passing rate (%GP) for different distance-to-agreement/dose difference (DTA/DD) criteria and low-dose thresholds.
Results:
The gamma index analysis shows that for patient-specific SRS/SRT VMAT QA with the portal dosimetry, the mean %GP is ≥98% for 2–3 mm/1–3% and Field+0%, +5% and +10% low-dose thresholds. When applying stricter spatial criteria of 1 mm, the mean %GP is >90% for DD of 2–3% and ≥88% for DD of 1%. The mean γmax ranges: 1·32 ± 1·33–2·63 ± 2·35 for 3 mm/1–3%, 1·57 ± 1·36–2·87 ± 2·29 for 2 mm/1–3% and 2·36 ± 1·83–3·58 ± 2·23 for 1 mm/1–3%. Similarly the mean γave ranges: 0·16 ± 0·06–0·19 ± 0·07 for 3 mm/1–3%, 0·21 ± 0·08–0·27 ± 0·10 for 2 mm/1–3% and 0·34 ± 0·14–0·49 ± 0·17 for 1 mm/1–3%. The mean γmax and mean γave increase with increased DTA and increased DD for all low-dose thresholds.
Conclusions:
The establishment of gamma criteria local action levels for SRS/SRT VMAT pre-treatment QA based on institutional resources is imperative as a useful tool for standardising the evaluation of EPID-based patient-specific SRS/SRT VMAT QA. Our data suggest that for intracranial SRS/SRT VMAT QA measured with the EPID, a stricter gamma criterion of 1 mm/2% or 1 mm/3% with ≥90% %GP could be used while still maintaining an in-control QA process with no extra burden on resources and time constraints.
Collapse
|
16
|
Alharthi T, Vial P, Holloway L, Thwaites D. Intrinsic detector sensitivity analysis as a tool to characterize ArcCHECK and EPID sensitivity to variations in delivery for lung SBRT VMAT plans. J Appl Clin Med Phys 2021; 22:229-240. [PMID: 33949087 PMCID: PMC8200424 DOI: 10.1002/acm2.13221] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/08/2021] [Accepted: 02/12/2021] [Indexed: 12/16/2022] Open
Abstract
PURPOSE To investigate intrinsic sensitivity of an electronic portal imaging device (EPID) and the ArcCHECK detector and to use this in assessing their performance in detecting delivery variations for lung SBRT VMAT. The effect of detector spatial resolution and dose matrix interpolation on the gamma pass rate was also considered. MATERIALS AND METHODS Fifteen patients' lung SBRT VMAT plans were used. Delivery variations (errors) were introduced by modifying collimator angles, multi-leaf collimator (MLC) field sizes and MLC field shifts by ±5, ±2, and ±1 degrees or mm (investigating 103 plans in total). EPID and ArcCHECK measured signals with introduced variations were compared to measured signals without variations (baseline), using OmniPro-I'mRT software and gamma criteria of 3%/3 mm, 2%/2 mm, 2%/1 mm, and 1%/1 mm, to test each system's basic performance. The measurement sampling resolution for each was also changed to 1 mm and results compared to those with the default detector system resolution. RESULTS Intrinsic detector sensitivity analysis, that is, comparing measurement to baseline measurement, rather than measurement to plan, demonstrated the intrinsic constraints of each detector and indicated the limiting performance that users might expect. Changes in the gamma pass rates for ArcCHECK, for a given introduced error, were affected only by dose difference (DD %) criteria. However, the EPID showed only slight changes when changing DD%, but greater effects when changing distance-to-agreement criteria. This is pertinent for lung SBRT where the minimum dose to the target will drop dramatically with geometric errors. Detector resolution and dose matrix interpolation have an impact on the gamma results for these SBRT plans and can lead to false positives or negatives in error detection if not understood. CONCLUSION The intrinsic sensitivity approach may help in the selection of more meaningful gamma criteria and the choice of optimal QA device for site-specific dose verification.
Collapse
Affiliation(s)
- Thahabah Alharthi
- Institute of Medical Physics, School of Physics, The University of Sydney, Sydney, NSW, Australia.,School of Medicine, Taif University, Taif, Saudi Arabia.,Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia.,Ingham Institute for Applied Medical Research, Sydney, NSW, Australia
| | - Phil Vial
- Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia.,Ingham Institute for Applied Medical Research, Sydney, NSW, Australia.,South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Lois Holloway
- Institute of Medical Physics, School of Physics, The University of Sydney, Sydney, NSW, Australia.,Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia.,Ingham Institute for Applied Medical Research, Sydney, NSW, Australia.,South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - David Thwaites
- Institute of Medical Physics, School of Physics, The University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
17
|
Allred BC, Shan J, Robertson DG, DeWees TA, Shen J, Liu W, Stoker JB. A method for quantitative evaluations of scanning-proton dose distributions. J Appl Clin Med Phys 2021; 22:193-201. [PMID: 33780142 PMCID: PMC8035555 DOI: 10.1002/acm2.13226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 01/14/2021] [Accepted: 02/24/2021] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Patient-Specific Quality Assurance (PSQA) measurement analysis depends on generating metrics representative of calculation and measurement agreement. Considering the heightened capability of discrete spot scanning protons to modulate individual dose voxels, a dose plane comparison approach that maintained all of the capabilities of the well-established γ test, but that also provided a more intuitive error parameterization, was desired. METHODS Analysis was performed for 300 dose planes compared by searching all calculated points within a fixed radius around each measured pixel to determine the dose deviation. Dose plane agreement is reported as the dose difference minimum (DDM) within an empirically established search radius: ΔDmin(r). This per-pixel metric is aggregated into a histogram binned by dose deviation. Search-radius criteria were based on a weighted-beamlet 3σ spatial deviation from imaging isocenter. Equipment setup error was mitigated during analysis using tracked image registration, ensuring beamlet deviations to be the dominant source of spatial error. The percentage of comparison points with <3% dose difference determined pass rate. RESULTS The mean beamlet radial deviation was 0.38mm from x-ray isocenter, with a standard deviation of 0.19mm, such that 99.9% of relevant pencil beams were within 1 mm of nominal. The dose-plane comparison data showed no change in passing rate between a 3%/1mm ΔDmin(r) analysis (97.6 +/- 3.6%) and a 3%/2mm γ test (97.7 +/- 3.2%). CONCLUSIONS PSQA dose-comparison agreements corresponding to a search radius outside of machine performance limits are likely false positives. However, the elliptical shape of the γ test is too dose-restrictive with a spatial-error threshold set at 1 mm. This work introduces a cylindrical search shape, proposed herein as more relevant to plan quality, as part of the new DDM planar-dose comparison algorithm. DDM accepts all pixels within a given dose threshold inside the search radius, and carries forward plan-quality metrics in a straightforward manner for evaluation.
Collapse
Affiliation(s)
- Bryce C Allred
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, USA
| | - Jie Shan
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, USA
| | | | - Todd A DeWees
- Department of Health Sciences Research, Mayo Clinic Arizona, Phoenix, AZ, USA
| | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, USA
| | - Wei Liu
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, USA
| | - Joshua B Stoker
- Department of Radiation Oncology, Mayo Clinic Arizona, Phoenix, AZ, USA
| |
Collapse
|
18
|
Shaw M, Lye J, Alves A, Hanlon M, Lehmann J, Supple J, Porumb C, Williams I, Geso M, Brown R. Measuring the dose in bone for spine stereotactic body radiotherapy. Phys Med 2021; 84:265-273. [PMID: 33773909 DOI: 10.1016/j.ejmp.2021.03.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/08/2021] [Accepted: 03/05/2021] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Current quality assurance of radiotherapy involving bony regions generally utilises homogeneous phantoms and dose calculations, ignoring the challenges of heterogeneities with dosimetry problems likely occurring around bone. Anthropomorphic phantoms with synthetic bony materials enable realistic end-to-end testing in clinical scenarios. This work reports on measurements and calculated corrections required to directly report dose in bony materials in the context of comprehensive end-to-end dosimetry audit measurements (63 plans, 6 planning systems). MATERIALS AND METHODS Radiochromic film and microDiamond measurements were performed in an anthropomorphic spine phantom containing bone equivalent materials. Medium dependent correction factors, kmed, were established using 6 MV and 10 MV Linear Accelerator Monte Carlo simulations to account for the detectors being calibrated in water, but measuring in regions of bony material. Both cortical and trabecular bony material were investigated for verification of dose calculations in dose-to-medium (Dm,m) and dose-to-water (Dw,w) scenarios. RESULTS For Dm,m calculations, modelled correction factors for cortical and trabecular bone in film measurements, and for trabecular bone in microDiamond measurements were 0.875(±0.1%), 0.953(±0.3%) and 0.962(±0.4%), respectively. For Dw,w calculations, the corrections were 0.920(±0.1%), 0.982(±0.3%) and 0.993(±0.4%), respectively. In the audit, application of the correction factors improves the mean agreement between treatment plans and measured microDiamond dose from -2.4%(±3.9%) to 0.4%(±3.7%). CONCLUSION Monte Carlo simulations provide a method for correcting the dose measured in bony materials allowing more accurate comparison with treatment planning system doses. In verification measurements, algorithm specific correction factors should be applied to account for variations in bony material for calculations based on Dm,m and Dw,w.
Collapse
Affiliation(s)
- Maddison Shaw
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia; School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia.
| | - Jessica Lye
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia; Olivia Newton John Cancer Wellness Centre, Melbourne, Australia
| | - Andrew Alves
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| | - Maximilian Hanlon
- Primary Standards Dosimetry Laboratory, ARPANSA, Melbourne, Australia
| | - Joerg Lehmann
- Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, Australia; School of Science, RMIT University, Melbourne, Australia; School of Mathematical and Physical Sciences, University of Newcastle, Australia; Institute of Medical Physics, University of Sydney, Australia
| | - Jeremy Supple
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| | - Claudiu Porumb
- Alfred Health Radiation Oncology, The Alfred Hospital, Melbourne, Australia
| | - Ivan Williams
- Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| | - Moshi Geso
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia
| | - Rhonda Brown
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| |
Collapse
|
19
|
Bourbonne V, Jaouen V, Hognon C, Boussion N, Lucia F, Pradier O, Bert J, Visvikis D, Schick U. Dosimetric Validation of a GAN-Based Pseudo-CT Generation for MRI-Only Stereotactic Brain Radiotherapy. Cancers (Basel) 2021; 13:1082. [PMID: 33802499 PMCID: PMC7959466 DOI: 10.3390/cancers13051082] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Stereotactic radiotherapy (SRT) has become widely accepted as a treatment of choice for patients with a small number of brain metastases that are of an acceptable size, allowing for better target dose conformity, resulting in high local control rates and better sparing of organs at risk. An MRI-only workflow could reduce the risk of misalignment between magnetic resonance imaging (MRI) brain studies and computed tomography (CT) scanning for SRT planning, while shortening delays in planning. Given the absence of a calibrated electronic density in MRI, we aimed to assess the equivalence of synthetic CTs generated by a generative adversarial network (GAN) for planning in the brain SRT setting. METHODS All patients with available MRIs and treated with intra-cranial SRT for brain metastases from 2014 to 2018 in our institution were included. After co-registration between the diagnostic MRI and the planning CT, a synthetic CT was generated using a 2D-GAN (2D U-Net). Using the initial treatment plan (Pinnacle v9.10, Philips Healthcare), dosimetric comparison was performed using main dose-volume histogram (DVH) endpoints in respect to ICRU 91 guidelines (Dmax, Dmean, D2%, D50%, D98%) as well as local and global gamma analysis with 1%/1 mm, 2%/1 mm and 2%/2 mm criteria and a 10% threshold to the maximum dose. t-test analysis was used for comparison between the two cohorts (initial and synthetic dose maps). RESULTS 184 patients were included, with 290 treated brain metastases. The mean number of treated lesions per patient was 1 (range 1-6) and the median planning target volume (PTV) was 6.44 cc (range 0.12-45.41). Local and global gamma passing rates (2%/2 mm) were 99.1 CI95% (98.1-99.4) and 99.7 CI95% (99.6-99.7) respectively (CI: confidence interval). DVHs were comparable, with no significant statistical differences regarding ICRU 91's endpoints. CONCLUSIONS Our study is the first to compare GAN-generated CT scans from diagnostic brain MRIs with initial CT scans for the planning of brain stereotactic radiotherapy. We found high similarity between the planning CT and the synthetic CT for both the organs at risk and the target volumes. Prospective validation is under investigation at our institution.
Collapse
Affiliation(s)
- Vincent Bourbonne
- Radiation Oncology Department, CHRU Brest, 2 Avenue Foch, 29200 Brest, France; (N.B.); (F.L.); (O.P.); (U.S.)
- Laboratoire de Traitement de l’Information Médicale, Unité Mixte de Recherche 1101, Institut National de la Santé et de la Recherche, Université de Bretagne Occidentale, 29200 Brest, France; (V.J.); (C.H.); (J.B.); (D.V.)
| | - Vincent Jaouen
- Laboratoire de Traitement de l’Information Médicale, Unité Mixte de Recherche 1101, Institut National de la Santé et de la Recherche, Université de Bretagne Occidentale, 29200 Brest, France; (V.J.); (C.H.); (J.B.); (D.V.)
- Institut Mines-Télécom Atlantique, 29200 Brest, France
| | - Clément Hognon
- Laboratoire de Traitement de l’Information Médicale, Unité Mixte de Recherche 1101, Institut National de la Santé et de la Recherche, Université de Bretagne Occidentale, 29200 Brest, France; (V.J.); (C.H.); (J.B.); (D.V.)
| | - Nicolas Boussion
- Radiation Oncology Department, CHRU Brest, 2 Avenue Foch, 29200 Brest, France; (N.B.); (F.L.); (O.P.); (U.S.)
- Laboratoire de Traitement de l’Information Médicale, Unité Mixte de Recherche 1101, Institut National de la Santé et de la Recherche, Université de Bretagne Occidentale, 29200 Brest, France; (V.J.); (C.H.); (J.B.); (D.V.)
| | - François Lucia
- Radiation Oncology Department, CHRU Brest, 2 Avenue Foch, 29200 Brest, France; (N.B.); (F.L.); (O.P.); (U.S.)
- Laboratoire de Traitement de l’Information Médicale, Unité Mixte de Recherche 1101, Institut National de la Santé et de la Recherche, Université de Bretagne Occidentale, 29200 Brest, France; (V.J.); (C.H.); (J.B.); (D.V.)
| | - Olivier Pradier
- Radiation Oncology Department, CHRU Brest, 2 Avenue Foch, 29200 Brest, France; (N.B.); (F.L.); (O.P.); (U.S.)
- Laboratoire de Traitement de l’Information Médicale, Unité Mixte de Recherche 1101, Institut National de la Santé et de la Recherche, Université de Bretagne Occidentale, 29200 Brest, France; (V.J.); (C.H.); (J.B.); (D.V.)
| | - Julien Bert
- Laboratoire de Traitement de l’Information Médicale, Unité Mixte de Recherche 1101, Institut National de la Santé et de la Recherche, Université de Bretagne Occidentale, 29200 Brest, France; (V.J.); (C.H.); (J.B.); (D.V.)
| | - Dimitris Visvikis
- Laboratoire de Traitement de l’Information Médicale, Unité Mixte de Recherche 1101, Institut National de la Santé et de la Recherche, Université de Bretagne Occidentale, 29200 Brest, France; (V.J.); (C.H.); (J.B.); (D.V.)
| | - Ulrike Schick
- Radiation Oncology Department, CHRU Brest, 2 Avenue Foch, 29200 Brest, France; (N.B.); (F.L.); (O.P.); (U.S.)
- Laboratoire de Traitement de l’Information Médicale, Unité Mixte de Recherche 1101, Institut National de la Santé et de la Recherche, Université de Bretagne Occidentale, 29200 Brest, France; (V.J.); (C.H.); (J.B.); (D.V.)
| |
Collapse
|
20
|
Ceylan C, Yondem Inal S, Senol E, Yilmaz B, Sahin S. Effect of Multileaf Collimator Leaf Position Error Determined by Picket Fence Test on Gamma Index Value in Patient-Specific Quality Assurance of Volumetric-Modulated Arc Therapy Plans. Cureus 2021; 13:e12684. [PMID: 33598374 PMCID: PMC7880508 DOI: 10.7759/cureus.12684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2021] [Indexed: 11/08/2022] Open
Abstract
Aim The correlation between the MLC QA (IBA Dosimetry, Germany) results of the picket fence test created with intentional errors and the patient's quality assurance (QA) evaluation was investigated to assess the impact of multileaf collimator (MLC) positioning error on patient QA. Materials and methods The picket fence, including error-free and intentional MLC errors, defined in Bank In, Bank Out, and Bank Both were analyzed using MLC QA. The QA of 15 plans consisting of stereotactic radiosurgery (SRS), stereotactic body radiotherapy (SBRT), and conventionally fractionated volumetric-modulated arc therapy (VMAT) acquired with electronic portal imaging devices (EPID) was evaluated in the presence of error-free and MLC errors. The QA of plans were analyzed with 2%/2 mm and 3%/3 mm criteria. Results The passing rates of the picket fence test were 97%, 92%, 91%, and 87% for error-free and intentional errors. The criterion of 3%/3 mm wasn't able to detect an MLC error for either SRS/SBRT or conventionally fractionated VMAT. The criterion of 2%/2mm was more sensitive to detect MLC error for the conventionally fractionated VMAT than SRS/SBRT. While only two of SBRT plans had <90%, four of conventionally fractionated VMAT plans had a <90% passing rate. Conclusion We found that the systematic MLC positioning errors defined with picket fence have a smaller but measurable impact on SRS/SBRT than the VMAT plan for a conventionally fractionated and relatively complex plan such as head and neck and endometrium cases.
Collapse
Affiliation(s)
- Cemile Ceylan
- Radiation Oncology Department, Istanbul Oncology Hospital, Istanbul, TUR
- Health Sciences Institute, Yeditepe University, Istanbul, TUR
| | - Serpil Yondem Inal
- Radiation Oncology Department, Memorial Bahcelievler Hospital, Istanbul, TUR
| | - Elif Senol
- Radiation Oncology Department, Memorial Bahcelievler Hospital, Istanbul, TUR
| | - Berrin Yilmaz
- Radiation Oncology Department, Istanbul Oncology Hospital, Istanbul, TUR
| | - Sevim Sahin
- Medical Imaging Department, Fenerbahçe University, Istanbul, TUR
| |
Collapse
|
21
|
Park JM, Choi CH, Wu HG, Kim JI. Correlation of the gamma passing rates with the differences in the dose-volumetric parameters between the original VMAT plans and actual deliveries of the VMAT plans. PLoS One 2020; 15:e0244690. [PMID: 33373394 PMCID: PMC7771856 DOI: 10.1371/journal.pone.0244690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 11/20/2020] [Indexed: 11/29/2022] Open
Abstract
Purpose The aim of this study was to investigate the correlations of the gamma passing rates (GPR) with the dose-volumetric parameter changes between the original volumetric modulated arc therapy (VMAT) plans and the actual deliveries of the VMAT plans (DV errors). We compared the correlations of the TrueBeam STx system to those of a C-series linac. Methods A total of 20 patients with head and neck (H&N) cancer were retrospectively selected for this study. For each patient, two VMAT plans with the TrueBeam STx and Trilogy (C-series linac) systems were generated under similar modulation degrees. Both the global and local GPRs with various gamma criteria (3%/3 mm, 2%/2 mm, 2%/1 mm, 1%/2 mm, and 1%/1 mm) were acquired with the 2D dose distributions measured using the MapCHECK2 detector array. During VMAT deliveries, the linac log files of the multi-leaf collimator positions, gantry angles, and delivered monitor units were acquired. The DV errors were calculated with the 3D dose distributions reconstructed using the log files. Subsequently, Spearman’s rank correlation coefficients (rs) and the corresponding p values were calculated between the GPRs and the DV errors. Results For the Trilogy system, the rs values with p < 0.05 showed weak correlations between the GPRs and the DV errors (rs<0.4) whereas for the TrueBeam STx system, moderate or strong correlations were observed (rs≥0.4). The DV errors in the V20Gy of the left parotid gland and those in the mean dose of the right parotid gland showed strong correlations (always with rs > 0.6) with the GPRs with gamma criteria except 3%/3 mm. As the GPRs increased, the DV errors decreased. Conclusion The GPRs showed strong correlations with some of the DV errors for the VMAT plans for H&N cancer with the TrueBeam STx system.
Collapse
Affiliation(s)
- Jong Min Park
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
- Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea
| | - Chang Heon Choi
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Hong-Gyun Wu
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
- Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea
| | - Jung-In Kim
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| |
Collapse
|
22
|
Ho HW, Yang CC, Lin HM, Chen HY, Huang CC, Wang SC, Lin YW. The feasibility and efficacy of new SBRT technique HyperArc for recurrent nasopharyngeal carcinoma: noncoplanar cone-based robotic system vs. noncoplanar high-definition MLC based Linac system. Med Dosim 2020; 46:164-170. [PMID: 33208290 DOI: 10.1016/j.meddos.2020.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 10/15/2020] [Accepted: 10/29/2020] [Indexed: 12/16/2022]
Abstract
The purpose of this study was to evaluate the feasibility and efficacy of HyperArc (HA) for recurrent nasopharyngeal cancer (NPC) by comparing it with the CyberKnife system (CK). Fifteen patients with recurrent nasopharyngeal cancer who were treated using the noncoplanar cone-based robotic CK system were enrolled. CK was delivered with a median dose of 37.5 Gy in 5 fractions. The delivered CK treatment plans were the sources for the corresponding homogeneous HA (HA-H) and inhomogeneous HA (HA-IH) plans. The HA-H plans were generated to meet the corresponding treatment plan criteria for the CK plans. The HA-IH plans were designed to emulate the corresponding inhomogeneous CK isodose distributions. These three SBRT treatment plans were compared with target coverage, sparing of organs at risk (OARs), and dose distribution metrics. The HA-H and HA-IH plans consistently exhibited CTV and PTV coverage levels similar or better to those of the CK plans but significantly reduced the dose to OARs. Using the HA techniques (both HA-H and HA-IH plans), the mean maximal doses to the spinal cord, brainstem, optic nerves, and optic chiasm were reduced by approximately 60%, compared to the CK plans. The high dose spillage, conformity, and homogeneity indices of the HA-H plans were significantly better than those of the CK plans. The HA-IH plans showed faster dose falloff and similar conformity of the HA-H plans and dose heterogeneity of the CK plans. Here we demonstrated the HA treatment plan system for recurrent NPC is feasible, either homogeneous or inhomogeneous delivery. Excellent sparing of OARs and dosimetric distribution and very efficient delivery make HA an attractive SBRT technique for recurrent NPC treatment.
Collapse
Affiliation(s)
- Hsiu-Wen Ho
- Department of Radiation Oncology, Chi Mei Medical Center, Tainan City 71004, Taiwan
| | - Ching-Chieh Yang
- Department of Radiation Oncology, Chi Mei Medical Center, Tainan City 71004, Taiwan; Department of Pharmacy, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan
| | - Hsiu-Man Lin
- Department of Radiation Oncology, Chi Mei Medical Center, Tainan City 71004, Taiwan
| | - Hsiao-Yun Chen
- Department of Radiation Oncology, Chi Mei Medical Center, Tainan City 71004, Taiwan
| | - Chun-Chiao Huang
- Department of Radiation Oncology, Chi Mei Medical Center, Tainan City 71004, Taiwan
| | - Shih-Chang Wang
- Department of Radiation Oncology, Chi Mei Medical Center, Tainan City 71004, Taiwan
| | - Yu-Wei Lin
- Department of Radiation Oncology, Chi Mei Medical Center, Tainan City 71004, Taiwan; Department of Pharmacy, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan; Department of Health and Nutrition, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan.
| |
Collapse
|
23
|
Niroomand‐Rad A, Chiu‐Tsao S, Grams MP, Lewis DF, Soares CG, Van Battum LJ, Das IJ, Trichter S, Kissick MW, Massillon‐JL G, Alvarez PE, Chan MF. Report of AAPM Task Group 235 Radiochromic Film Dosimetry: An Update to TG‐55. Med Phys 2020; 47:5986-6025. [DOI: 10.1002/mp.14497] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Affiliation(s)
| | | | | | | | | | | | - Indra J. Das
- Radiation Oncology Northwestern University Memorial Hospital Chicago IL USA
| | - Samuel Trichter
- New York‐Presbyterian HospitalWeill Cornell Medical Center New York NY USA
| | | | - Guerda Massillon‐JL
- Instituto de Fisica Universidad Nacional Autonoma de Mexico Mexico City Mexico
| | - Paola E. Alvarez
- Imaging and Radiation Oncology Core MD Anderson Cancer Center Houston TX USA
| | - Maria F. Chan
- Memorial Sloan Kettering Cancer Center Basking Ridge NJ USA
| |
Collapse
|
24
|
Chow VUY, Kan MWK, Chan ATC. Patient-specific quality assurance using machine log files analysis for stereotactic body radiation therapy (SBRT). J Appl Clin Med Phys 2020; 21:179-187. [PMID: 33073897 PMCID: PMC7700944 DOI: 10.1002/acm2.13053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/10/2020] [Accepted: 09/18/2020] [Indexed: 12/31/2022] Open
Abstract
An in‐house trajectory log analysis program (LOGQA) was developed to evaluate the delivery accuracy of volumetric‐modulated arc therapy (VMAT) for stereotactic body radiation therapy (SBRT). Methods have been established in LOGQA to provide analysis on dose indices, gantry angles, and multi‐leaf collimator (MLC) positions. Between March 2019 and May 2020, 120 VMAT SBRT plans of various treatment sites using flattening filter‐free (FFF) mode were evaluated using both LOGQA and phantom measurements. Gantry angles, dose indices, and MLC positions were extracted from log and compared with each plan. Integrated transient fluence map (ITFM) was reconstructed from log to examine the deviation of delivered fluence against the planned one. Average correlation coefficient of dose index versus gantry angle and ITFM for all patients were 1.0000, indicating that the delivered beam parameters were in good agreement with planned values. Maximum deviation of gantry angles and monitor units (MU) of all patients were less than 0.2 degree and 0.03 % respectively. Regarding MLC positions, maximum and root‐mean‐square (RMS) deviations from planned values were less than 0.6 mm and 0.3 mm respectively, indicating that MLC positions during delivery followed planned values in precise manner. Results of LOGQA were consistent with measurement, where all gamma‐index passing rates were larger than 95 %, with 2 %/2 mm criteria. Three types of intentional errors were introduced to patient plan for software validation. LOGQA was found to recognize the introduced errors of MLC positions, gantry angles, and dose indices with magnitudes of 1 mm, 1 degree, and 5 %, respectively, which were masked in phantom measurement. LOGQA was demonstrated to have the potential to reduce or even replace patient‐specific QA measurements for SBRT plan delivery provided that the frequency and amount of measurement‐based machine‐specific QA can be increased to ensure the log files record real values of machine parameters.
Collapse
Affiliation(s)
- Vivian U Y Chow
- Department of Clinical Oncology, Prince of Wales Hospital, Hong Kong SAR, China
| | - Monica W K Kan
- Department of Clinical Oncology, Prince of Wales Hospital, Hong Kong SAR, China.,Department of Clinical Oncology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Anthony T C Chan
- Department of Clinical Oncology, Prince of Wales Hospital, Hong Kong SAR, China.,Department of Clinical Oncology, The Chinese University of Hong Kong, Hong Kong SAR, China
| |
Collapse
|
25
|
Thaper D, Kamal R, Singh G, Oinam AS, Yadav HP, Kumar V. Derivative-based gamma index: a novel methodology for stringent patient-specific quality assurance in the stereotactic treatment planning of liver cancer. Biomed Phys Eng Express 2020; 6. [PMID: 35125347 DOI: 10.1088/2057-1976/ababf3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 08/03/2020] [Indexed: 11/12/2022]
Abstract
Objective:The development of a stringent derivative-based gamma (DBG) index for patient-specific QA in stereotactic radiotherapy treatment planning (SRTP) to account for the spatial change in dose.Methods:Twenty-five patients of liver SBRT were selected retrospectively for this study. Deliberately, two different kinds of treatment planning approaches were used for each patient. Firstly, the treatment plans were generated using a conventional treatment planning (CTP) approach in which the target was covered with a homogeneous dose along with the nominal dose fall-off around the treatment field. Subsequently, the other treatment plans were generated using an SRTP approach with the intent of heterogeneous dose within the target region along with a steeper dose gradient outside the treatment field as much as possible. For both kinds of treatment plans, two dimensional (2D) conventional gamma (CG) and DBG analysis were performed using the 2D ion chamber array and radiochromic film.Results:Difference in the DBG index was statistically significant whereas, for CG analysis, the difference in CG index was insignificant for both types of treatment plans (CTP and SRTP). A significant positive correlation was observed between the difference in the DBG index and the difference in HI for high gamma criteria.Conclusion:The DBG evaluation is found to be more rigorous, and sensitive to the only SRTP. The proposed method could be opted-in the routine clinical practice in addition to CG.Advances in knowledge:DBG is more sensitive to detect the spatial change of dose, especially in high dose gradient regions.
Collapse
Affiliation(s)
- Deepak Thaper
- Centre for Medical Physics, Panjab University, Chandigarh, India.,Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Rose Kamal
- Centre for Medical Physics, Panjab University, Chandigarh, India.,Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Gaganpreet Singh
- Centre for Medical Physics, Panjab University, Chandigarh, India.,Department of Radiotherapy, PGIMER, Regional Cancer Centre, Chandigarh, India
| | - Arun S Oinam
- Department of Radiotherapy, PGIMER, Regional Cancer Centre, Chandigarh, India
| | - Hanuman P Yadav
- Department of Radiation Oncology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Vivek Kumar
- Centre for Medical Physics, Panjab University, Chandigarh, India
| |
Collapse
|
26
|
Bai L, Xiao Q, Wang Q, Zhao J, Li G, Bai S. Dosimetric characteristics of a 2D silicon diode array for stereotactic radiotherapy end-to-end patient-specific QA. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.108885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
27
|
Bai H, Zhu S, Wu X, Liu X, Chen F, Yan J. Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS). Radiat Oncol 2020; 15:161. [PMID: 32631380 PMCID: PMC7336463 DOI: 10.1186/s13014-020-01603-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/23/2020] [Indexed: 02/06/2023] Open
Abstract
Objective To explore the efficacy and sensitivity of 3D gamma analysis and bio-mathematical model for cervical cancer in detecting dose changes caused by dose-calculation-grid-size (DCGS). Methods 17 patients’ plans for cervical cancer were enrolled (Pinnacle TPS, VMAT), and the DCGS was changed from 2.0 mm to 5.0 mm to calculate the planned dose respectively. The dose distribution calculated by DCGS = 2.0 mm as the “reference” data set (RDS), the dose distribution calculated by the rest DCGS as the“measurement”data set (MDS), the 3D gamma passing rates and the (N) TCPs of the all structures under different DCGS were obtained, and then analyze the ability of 3D gamma analysis and (N) TCP model in detecting dose changes and what factors affect this ability. Results The effect of DCGS on planned dose was obvious. When the gamma standard was 1.0 mm, 1.0 and 10.0%, the difference of the results of the DCGS on dose-effect could be detected by 3D gamma analysis (all p value < 0.05). With the decline of the standard, 3D gamma analysis’ ability to detect this difference shows weaker. When the standard was 1.0 mm, 3.0 and 10.0%, the p value of > 0.05 accounted for the majority. With DCGS = 2.0 mm being RDS, ∆gamma-passing-rate presented the same trend with ∆(N) TCPs of all structures except for the femurs only when the 1.0 mm, 1.0 and 10.0% standards were adopted for the 3D gamma analysis. Conclusions The 3D gamma analysis and bio-mathematical model can be used to analyze the effect of DCGS on the planned dose. For comparison, the former’s detection ability has a lot to do with the designed standard, and the latter’s capability is related to the parameters and calculated accuracy instrinsically.
Collapse
Affiliation(s)
- Han Bai
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
| | - Sijin Zhu
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
| | - Xingrao Wu
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China.
| | - Xuhong Liu
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
| | - Feihu Chen
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
| | - Jiawen Yan
- Department of Radiation Oncology, Yunnan Tumor Hospital, The Third Affiliated Hospital of Kunming Medical University, No.519 Kunzhou, Road, Xishan District, Kunming, Yunnan, China
| |
Collapse
|
28
|
Ghareeb F, Esposito A, Lencart J, Santos JA. Localized extra focal dose collimator angle dependence during VMAT: An out-of-field Monte Carlo study using PRIMO software. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.108694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
29
|
Improvement in sensitivity of radiochromic 3D dosimeter based on rigid polyurethane resin by incorporating tartrazine. PLoS One 2020; 15:e0230410. [PMID: 32176733 PMCID: PMC7075553 DOI: 10.1371/journal.pone.0230410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 03/01/2020] [Indexed: 11/25/2022] Open
Abstract
We investigated the influence of incorporating tartrazine on the dose response characteristics of radiochromic 3D dosimeters based on polyurethane resin. We use three types of polyurethane resins with different Shore hardness values: 30 A, 50 A, and 80 D. PRESAGE dosimeters are fabricated with different chemical components and concentrations. Tartrazine (Yellow No. 5) helps incorporate a yellow dye to fabricate the dosimeter. Elemental composition is analyzed with the Zeff. Three sets of six different PRESAGE dosimeters were fabricated to investigate the effects of incorporating yellow dye on the dose response characteristics of the dosimeter. The dose response curve was obtained by measuring the optical absorbance using a spectrometer and optical density using optical CT, respectively. The energy and dose rate dependences are evaluated for the dosimeter with the highest sensitivity. For the optical density measurement, significant sensitivity enhancements of 36.6% and 32.7% were achieved in polyurethane having a high Shore hardness of 80 D and 50 A by incorporating tartrazine, respectively. The same results were obtained in the optical absorbance measurements. The ratio of the Zeff of the dosimeter with 80 D Shore hardness to water was 1.49. The polyurethane radiochromic dosimeter with a Shore hardness of 80 D showed the highest sensitivity and energy and dose rate independence upon the incorporation of tartrazine.
Collapse
|
30
|
Retrospective analysis of portal dosimetry pre-treatment quality assurance of hybrid IMRT breast treatment plans. JOURNAL OF RADIOTHERAPY IN PRACTICE 2020. [DOI: 10.1017/s1460396920000072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractBackground:The purpose of this study is to evaluate the effectiveness and sensitivity of the Varian portal dosimetry (PD) system as a quality assurance (QA) tool for breast intensity-modulated radiation therapy (IMRT) treatment plans.Materials and methods:Four hundred portal dose images from 200 breast cancer patient IMRT treatment plans were analysed. The images were obtained using Varian PortalVision electronic portal imaging devices (EPIDs) on Varian TrueBeam Linacs. Three patient plans were selected, and the multi-leaf collimator (MLC) positions were randomly altered by a mean of 0·5, 1, 1·5 and 2 mm with a standard deviation of 0·1 mm on 50, 75 and 100% of control points. Using the improved/global gamma calculation algorithm with a low-dose threshold of 10% in the EPID, the change in gamma passing rates for 3%/3 mm, 2%/2 mm and 1%/1 mm criterion was analysed as a function of the introduced error. The changes in the dose distributions of clinical target volume and organ at risk due to MLC positioning errors were also analysed.Results:Symmetric and asymmetric breast or chest wall plan fields are different in delivery as well as in the QA. An average gamma passing rate of 99·8 ± 0·5 is presented for 3%/3 mm symmetric plans and 96·9 ± 4·5 is presented for 3%/3 mm asymmetric plans. An average gamma passing rate of 98·4 ± 4·3 is presented for 2%/2 mm symmetric plans and 89·7 ± 9·5 is presented for 2%/2 mm asymmetric plans. A large-induced error in MLC positioning (2·0 mm, 100% of control points) results in an insignificant change in dose that would be delivered to the patient. However, EPID portal dosimetry is sensitive enough to detect even the slightest change in MLC positioning error (0·5 mm, 50% of control points).Conclusions:Stricter pre-treatment QA action levels can be established for breast IMRT plans utilising EPID. For improved sensitivity, a multigamma criteria approach is recommended. The PD tool is sensitive enough to detect MLC positioning errors that contribute to even insignificant dose changes.
Collapse
|
31
|
Wang R, Du Y, Yao K, Liu Z, Wang H, Yue H, Zhang Y, Wu H. Halcyon clinical performance evaluation: A log file-based study in comparison with a C-arm Linac. Phys Med 2020; 71:14-23. [PMID: 32086148 DOI: 10.1016/j.ejmp.2020.01.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/27/2019] [Accepted: 01/26/2020] [Indexed: 12/28/2022] Open
Abstract
PURPOSE The aim of this study is to compare the dosimetric and mechanical accuracy of Volumetric Modulation Arc Therapy (VMAT) delivery on the Halcyon, a recent ring-shaped Treatment Delivery System (TDS) featuring fast rotating gantry, with a conventional C-arm Linac. METHODS The comparison was performed via log file analysis, where mechanical parameters of related components was extracted. 480 and 3951 VMAT log files of clinically delivered fractions from a Halcyon and a TrueBeam Linac were analyzed respectively. The relations between mechanical parameters and errors were extensively explored to further investigate the differences between the two Linacs. The mechanical parameter fluctuations were taken into account for dose recalculations, and the Dose Volume Parameters (DVP) on the PTV were evaluated to quantify such dosimetric variations. RESULTS The Multi-Leaf Collimator (MLC) leaf mean Root Mean Square (RMS) errors were 0.028 mm and 0.031 mm for Halcyon and TrueBeam respectively. Maximum systematic error on the MLC leaves introduced by the gravity effect were 0.04 mm and 0.01 mm for the Halcyon and TrueBeam respectively. Thanks to the O-ring design, the Halcyon achieved 0.035° in mean RMS error in gantry angle compared with the 0.065° of the TrueBeam. Overall mechanical errors introduced similar levels of dose-volume parameter variations (about 0.1%) on both Linacs. CONCLUSION The Halcyon TDS can achieve similar mechanical leaf positioning accuracy compared with the TrueBeam TDS with a doubled delivery speed. In terms of dosimetric accuracy, The DVP standard deviations on the studied TB are generally larger than that on the Halcyon.
Collapse
Affiliation(s)
- Ruoxi Wang
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Yi Du
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Kaining Yao
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Zhuolun Liu
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Hanlin Wang
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Haizhen Yue
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Yibao Zhang
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Hao Wu
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China.
| |
Collapse
|
32
|
Xia Y, Adamson J, Zlateva Y, Giles W. Application of TG-218 action limits to SRS and SBRT pre-treatment patient specific QA. JOURNAL OF RADIOSURGERY AND SBRT 2020; 7:135-147. [PMID: 33282467 PMCID: PMC7717087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 06/25/2020] [Indexed: 06/12/2023]
Abstract
AAPM TG-218 provides recommendations for standard IMRT pre-treatment QA without giving specifics for stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT). In light of this, our purpose is to report our experience with applying TG-218 recommendations to a large multicenter clinical SRS and SBRT program for a range of diverse clinical pre-treatment QA systems. Pre-treatment QA systems included Delta4 (Scandidos), Portal Dosimetry (Varian Medical Systems), ArcCHECK (SunNuclear), and SRS MapCHECK (SunNuclear). Plans were stratified by technique for each QA system, and included intracranial and extracranial IMRT and VMAT (total QA cases n=275). Gamma analysis was re-analyzed with spatial/dose criteria combinations ranging from 1 to 3 mm and 1% to 4%, and action and tolerance limits were calculated per plan type and compared to the "universal" TG-218 action limit of 90%. The analysis indicated that spatial tolerance criteria could be tightened to 1 mm while still maintaining an in-control QA process for all QA systems evaluated.
Collapse
Affiliation(s)
- Yuqing Xia
- Medical Physics Graduate Program, Duke Kunshan University, Kunshan, China 215316
| | - Justus Adamson
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27708, USA
| | - Yana Zlateva
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27708, USA
| | - Will Giles
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27708, USA
| |
Collapse
|
33
|
Prediction of VMAT delivery accuracy with textural features calculated from fluence maps. Radiat Oncol 2019; 14:235. [PMID: 31870403 PMCID: PMC6929348 DOI: 10.1186/s13014-019-1441-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 12/09/2019] [Indexed: 11/30/2022] Open
Abstract
Background Comprehensively textural feature performance test from volumetric modulated arc therapy (VMAT) fluences to predict plan delivery accuracy. Methods A total of 240 VMAT plans for various treatment sites were analyzed, with Trilogy and TrueBeam STx systems. Fluence maps superposed fluences at each control point per plan. The textural features were the angular second moment (ASM), inverse difference moment (IDM), contrast, variance, correlation, and entropy, calculated from fluence maps using three displacement distances. Correlation analysis of textural feature performance as predictors of VMAT delivery accuracy used global gamma passing rates with MapCHECK2 and ArcCHECK dosimeters, and mechanical delivery errors calculated from machine log files. Results Spearman’s rank correlation coefficients (r) of the ASM (d = 10) to the gamma passing rates with 1%/2 mm using the MapCHECK2 were 0.358 and 0.519, respectively (p < 0.001). For the ArcCHECK, they were 0.273 (p = 0.001) and 0.259 (p = 0.009), respectively. The r-values of the ASM (d = 10) to the Trilogy and TrueBeam STx MLC errors were − 0.843 and − 0.859, respectively (p < 0.001), and those to the MU delivery errors were − 0.482 and − 0.589, respectively (p < 0.001). The ASM (d = 10) showed better performance in predicting VMAT delivery accuracy. Conclusions The ASM (d = 10) calculated from VMAT plan fluence maps were strongly correlated with global gamma passing rates and MLC delivery errors, and can predict VMAT delivery accuracy.
Collapse
|
34
|
Yu L, Kairn T, Trapp J, Crowe SB. Technical note: A modified gamma evaluation method for dose distribution comparisons. J Appl Clin Med Phys 2019; 20:193-200. [PMID: 31282112 PMCID: PMC6612697 DOI: 10.1002/acm2.12606] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/25/2019] [Accepted: 02/20/2019] [Indexed: 11/09/2022] Open
Abstract
Purpose In this work we have developed a novel method of dose distribution comparison, the inverse gamma (IG) evaluation, by modifying the commonly used gamma evaluation method. Methods The IG evaluation calculates the gamma criteria (dose difference criterion, ΔD, or distance‐to‐agreement criterion, Δd) that are needed to achieve a predefined pass rate or gamma agreement index (GAI). In‐house code for evaluating IG with a fixed ΔD of 3% was developed using Python (v3.5.2) and investigated using treatment plans and measurement data from 25 retrospective patient specific quality assurance tests (53 individual arcs). Results It was found that when the desired GAI was set to 95%, approximately three quarters of the arcs tested were able to achieve Δd within 1 mm (mean Δd: 0.7 ± 0.5 mm). The mean Δd required in order for all points to pass the gamma evaluation (i.e., GAI = 100%) was 4.5 ± 3.1 mm. The possibility of evaluating IG by fixing the Δd or ΔD/Δd, instead of fixing the ΔD at 3%, was also investigated. Conclusion The IG method and its indices have the potential to be implemented clinically to quantify the minimum dose and distance criteria based on a specified GAI. This method provides additional information to augment standard gamma evaluation results during patient specific quality assurance testing of individual treatment plans. The IG method also has the potential to be used in retrospective audits to determine an appropriate set of local gamma criteria and action levels based on a cohort of patient specific quality assurance plans.
Collapse
Affiliation(s)
- Liting Yu
- Royal Brisbane & Women's Hospital, Herston, QLD, Australia.,Queensland University of Technology, Brisbane, QLD, Australia
| | - Tanya Kairn
- Royal Brisbane & Women's Hospital, Herston, QLD, Australia.,Queensland University of Technology, Brisbane, QLD, Australia
| | - Jamie Trapp
- Queensland University of Technology, Brisbane, QLD, Australia
| | - Scott B Crowe
- Royal Brisbane & Women's Hospital, Herston, QLD, Australia.,Queensland University of Technology, Brisbane, QLD, Australia
| |
Collapse
|
35
|
Yu L, Tang TLS, Cassim N, Livingstone A, Cassidy D, Kairn T, Crowe SB. Analysis of dose comparison techniques for patient-specific quality assurance in radiation therapy. J Appl Clin Med Phys 2019; 20:189-198. [PMID: 31613053 PMCID: PMC6839377 DOI: 10.1002/acm2.12726] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 08/08/2019] [Accepted: 08/22/2019] [Indexed: 11/15/2022] Open
Abstract
Purpose Gamma evaluation is the most commonly used technique for comparison of dose distributions for patient‐specific pretreatment quality assurance in radiation therapy. Alternative dose comparison techniques have been developed but not widely implemented. This study aimed to compare and evaluate the performance of several previously published alternatives to the gamma evaluation technique, by systematically evaluating a large number of patient‐specific quality assurance results. Methods The agreement indices (or pass rates) for global and local gamma evaluation, maximum allowed dose difference (MADD) and divide and conquer (D&C) techniques were calculated using a selection of acceptance criteria for 429 patient‐specific pretreatment quality assurance measurements. Regression analysis was used to quantify the similarity of behavior of each technique, to determine whether possible variations in sensitivity might be present. Results The results demonstrated that the behavior of D&C gamma analysis and MADD box analysis differs from any other dose comparison techniques, whereas MADD gamma analysis exhibits similar performance to the standard global gamma analysis. Local gamma analysis had the least variation in behavior with criteria selection. Agreement indices calculated for 2%/2 mm and 2%/3 mm, and 3%/2 mm and 3%/3 mm were correlated for most comparison techniques. Conclusion Radiation oncology treatment centers looking to compare between different dose comparison techniques, criteria or lower dose thresholds may apply the results of this study to estimate the expected change in calculated agreement indices and possible variation in sensitivity to delivery dose errors.
Collapse
Affiliation(s)
- Liting Yu
- Royal Brisbane and Women's Hospital, Herston, Qld., Australia.,Queensland University of Technology, Brisbane, Qld., Australia
| | - Timothy L S Tang
- Queensland University of Technology, Brisbane, Qld., Australia.,Beacon International Specialist Centre, Petaling Jaya, Malaysia
| | - Naasiha Cassim
- Royal Brisbane and Women's Hospital, Herston, Qld., Australia
| | | | - Darren Cassidy
- Royal Brisbane and Women's Hospital, Herston, Qld., Australia
| | - Tanya Kairn
- Royal Brisbane and Women's Hospital, Herston, Qld., Australia.,Queensland University of Technology, Brisbane, Qld., Australia
| | - Scott B Crowe
- Royal Brisbane and Women's Hospital, Herston, Qld., Australia.,Queensland University of Technology, Brisbane, Qld., Australia
| |
Collapse
|
36
|
Shawata AS, Akl MF, Elshahat KM, Baker NA, Ahmed MT. Evaluation of different planning methods of 3DCRT, IMRT, and RapidArc for localized prostate cancer patients: planning and dosimetric study. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2019. [DOI: 10.1186/s43055-019-0021-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
37
|
Chun M, Joon An H, Kwon O, Oh DH, Park JM, Kim JI. Impact of plan parameters and modulation indices on patient-specific QA results for standard and stereotactic VMAT. Phys Med 2019; 62:83-94. [PMID: 31153402 DOI: 10.1016/j.ejmp.2019.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 05/03/2019] [Accepted: 05/04/2019] [Indexed: 12/30/2022] Open
Abstract
PURPOSE To demonstrate the impact of modulation indices and plan parameters on the gamma passing rates (GPR) of patient-specific quality assurance of standard and stereotactic volumetric modulated arc therapy (VMAT) plans. METHODS A total of 758 patients' QA plans were utilized, including standard VMAT plans with Trilogy (n = 87, group A) and TreuBeam STx (n = 332, group B), and 339 stereotactic VMAT plans with TrueBeam STx (group C). Modulation indices were obtained considering the speed and acceleration of the multileaf collimator (MLC) (MIs, MIa), and MLC, gantry speed, and dose rate changes (MIt). The mean aperture size (MA), monitor unit (MU), and amount of jaw tracking (%JT) were acquired. Gamma analysis was performed with 2 mm/2% and 1 mm/2% for the standard and stereotactic VMAT plans, respectively. Statistical analyses were performed to investigate the correlation between modulation index/plan parameters and GPR. RESULTS Spearman's rank correlation to GPRs with MIs, MIa, and MIt, were -0.44, -0.45, and -0.46 for group A; -0.39, -0.37, and -0.38 for group B; and -0.04, -0.11, and -0.10 for group C, respectively. While MU and MA showed significant correlations in all groups, %JT showed a significant correlation only with stereotactic VMAT plans. The most influential parameter combinations were MU-MA (rs = 0.50), MIs-%JT (rs = 0.43), and MU-%JT (rs = 0.38) for groups A, B, and C, respectively. CONCLUSIONS MLC modulation mostly affected the GPR in the delivery of standard VMAT plans, while MU and %JT showed more importance in stereotactic VMAT plans.
Collapse
Affiliation(s)
- Minsoo Chun
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea; Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Hyun Joon An
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Ohyun Kwon
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Do Hoon Oh
- Department of Radiation Oncology, Chung-Ang University Hospital, Seoul, Republic of Korea
| | - Jong Min Park
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea; Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea; Center for Convergence Research on Robotics, Advanced Institutes of Convergence Technology, Suwon, Republic of Korea
| | - Jung-In Kim
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea; Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.
| |
Collapse
|
38
|
Park JM, Kim JI, Park SY. Modulation indices and plan delivery accuracy of volumetric modulated arc therapy. J Appl Clin Med Phys 2019; 20:12-22. [PMID: 31038843 PMCID: PMC6560241 DOI: 10.1002/acm2.12589] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 01/31/2019] [Accepted: 03/10/2019] [Indexed: 12/25/2022] Open
Abstract
PURPOSE We evaluated the performance of various modulation indices (MI) for volumetric modulated arc therapy (VMAT) to predict plan delivery accuracy. METHODS The specific indices evaluated were MI quantifying the mechanical uncertainty (MIt ), MI quantifying the mechanical and dose calculation uncertainties (MIc ), MI for station parameter optimized radiation therapy (MISPORT ), modulation complexity score for VMAT (MCSv ), leaf travel modulation complexity score (LTMCS), plan averaged beam area (PA), plan averaged beam irregularity (PI), plan averaged beam modulation (PM), and plan normalized monitor unit (PMU) to predict VMAT delivery accuracy. By utilizing 240 VMAT plans generated with the Trilogy and TrueBeam STx, Spearman's rank correlation coefficients (r) were calculated between the MIs and measures of conventional methods. RESULTS For the Trilogy system, MIc showed the highest r values with gamma passing rates (GPRs) (r = -0.624 with P < 0.001 for MapCHECK2 and r = -0.655 with P < 0.001 for ArcCHECK). For TrueBeam STx, MIc also showed the highest r values with GPRs (r = -0.625 with P < 0.001 for the MapCHECK2 and r = -0.561 with P < 0.001 for the ArcCHECK). The MIt and MIc showed the highest r values to the MLC position errors for the Trilogy and TrueBeam STx systems (r = 0.770 with P < 0.001 and r = 0.712 with P < 0.001, respectively). The PA showed the highest percent of r values (P < 0.05) to differences in the dose-volume parameters between original VMAT plans and actual deliveries for the Trilogy systems (30.9%). Both the MIt and MIc showed the highest percent of r values (P < 0.05) to differences in the dose-volume parameters between original VMAT plans and actual deliveries for the TrueBeam STx systems (31.8%). CONCLUSION To comprehensively review the results, the MIc showed the best performance to predict the VMAT delivery accuracy.
Collapse
Affiliation(s)
- Jong Min Park
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.,Institute for Smart System, Robotics Research Laboratory for Extreme Environments, Advanced Institutes of Convergence Technology, Suwon, Korea
| | - Jung-In Kim
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - So-Yeon Park
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.,Department of Radiation Oncology, Veterans Health Service Medical Center, Seoul, Korea
| |
Collapse
|
39
|
Evaluation of the plan delivery accuracy of intensity-modulated radiation therapy by texture analysis using fluence maps. Phys Med 2019; 59:64-74. [DOI: 10.1016/j.ejmp.2019.02.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 02/18/2019] [Accepted: 02/20/2019] [Indexed: 02/07/2023] Open
|
40
|
Alharthi T, Arumugam S, Vial P, Holloway L, Thwaites D. EPID sensitivity to delivery errors for pre-treatment verification of lung SBRT VMAT plans. Phys Med 2019; 59:37-46. [PMID: 30928064 DOI: 10.1016/j.ejmp.2019.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/31/2019] [Accepted: 02/10/2019] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To study the sensitivity of an Electronic Portal Imaging Device (EPID) in detecting delivery errors for VMAT lung stereotactic body radiotherapy (SBRT) using the Collapsed Arc method. METHODS Baseline VMAT plans and plans with errors intentionally introduced were generated for 15 lung SBRT patients. Three types of errors were introduced by modifying collimator angles and multi-leaf collimator (MLC) field sizes (MLCFS) and MLC shifts by ±5, ±2, and ±1° or millimeters. A total of 103 plans were measured with EPID on an Elekta Synergy Linear Accelerator (Agility MLC) and compared to both the original treatment planning system (TPS) Collapsed Arc dose matrix and the no-error plan baseline EPID measurements. Gamma analysis was performed using the OmniPro-I'mRT (IBA Dosimetry) software and gamma criteria of 1%/1 mm, 2%/1 mm, 2%/2 mm, and 3%/3. RESULTS When the error-introduced EPID measured dose matrices were compared to the TPS matrices, the majority of simulated errors were detected with gamma tolerance of 2%/1 mm and 1%/1 mm. When the error-introduced EPID measured dose matrices were compared to the baseline EPID measurements, all the MLCFS and MLC shift errors, and ±5°collimator errors were detected using 2%/1 mm and 1%/1 mm gamma criteria. CONCLUSION This work demonstrates the feasibility and effectiveness of the collapsed arc technique and EPID for pre-treatment verification of lung SBRT VMAT plans. The EPID was able to detect the majority of MLC and the larger collimator errors with sensitivity to errors depending on the gamma tolerances.
Collapse
Affiliation(s)
- Thahabah Alharthi
- Institute of Medical Physics, School of Physics, The University of Sydney, Sydney, New South Wales, Australia; School of Medicine, Taif University, Taif, Saudi Arabia; Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia; Ingham Institute for Applied Medical Research, Sydney, NSW, Australia.
| | - Sankar Arumugam
- Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia; South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Phil Vial
- Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia; Ingham Institute for Applied Medical Research, Sydney, NSW, Australia; South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Lois Holloway
- Institute of Medical Physics, School of Physics, The University of Sydney, Sydney, New South Wales, Australia; Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia; Ingham Institute for Applied Medical Research, Sydney, NSW, Australia; South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - David Thwaites
- Institute of Medical Physics, School of Physics, The University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
41
|
Giglioli FR, Gallio E, Franco P, Badellino S, Ricardi U, Fiandra C. Clinical evaluation of a transmission detector system and comparison with a homogeneous 3D phantom dosimeter. Phys Med 2019; 58:159-164. [DOI: 10.1016/j.ejmp.2019.01.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 01/23/2019] [Accepted: 01/26/2019] [Indexed: 11/16/2022] Open
|
42
|
Lee M, Yoon K, Cho B, Kim SS, Song SY, Choi EK, Ahn S, Lee SW, Kwak J. Comparing phase- and amplitude-gated volumetric modulated arc therapy for stereotactic body radiation therapy using 3D printed lung phantom. J Appl Clin Med Phys 2019; 20:107-113. [PMID: 30667581 PMCID: PMC6371017 DOI: 10.1002/acm2.12533] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 12/16/2018] [Accepted: 12/29/2018] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To compare the dosimetric impact and treatment delivery efficacy of phase-gated volumetric modulated arc therapy (VMAT) vs amplitude-gated VMAT for stereotactic body radiation therapy (SBRT) for lung cancer by using realistic three-dimensional-printed phantoms. METHODS Four patient-specific moving lung phantoms that closely simulate the heterogeneity of lung tissue and breathing patterns were fabricated with four planning computed tomography (CT) images for lung SBRT cases. The phantoms were designed to be bisected for the measurement of two-dimensional dose distributions by using EBT3 dosimetry film. The dosimetric accuracy of treatment under respiratory motion was analyzed with the gamma index (2%/1 mm) between the plan dose and film dose measured under phase- and amplitude-gated VMAT. For the validation of the direct usage of the real-time position management (RPM) data for respiratory motion, the relationship between the RPM signal and the diaphragm position was measured by four-dimensional CT. By using data recorded during the beam delivery of both phase- and amplitude-gated VMAT, the total time intervals were compared for each treatment mode. RESULTS Film dosimetry showed a 5.2 ± 4.2% difference of gamma passing rate (2%/1 mm) on average between the phase- vs amplitude-gated VMAT [77.7% (72.7%-85.9%) for the phase mode and 82.9% (81.4%-86.2%) for the amplitude mode]. For delivery efficiency, frequent interruptions were observed during the phase-gated VMAT, which stopped the beam delivery and required a certain amount of time before resuming the beam. This abnormality in phase-gated VMAT caused a prolonged treatment delivery time of 366 s compared with 183 s for amplitude-gated VMAT. CONCLUSIONS Considering the dosimetric accuracy and delivery efficacy between the gating methods, amplitude mode is superior to phase mode for gated VMAT treatment.
Collapse
Affiliation(s)
- Minsik Lee
- Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - KyoungJun Yoon
- Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Byungchul Cho
- Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Su Ssan Kim
- Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Si Yeol Song
- Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Eun Kyung Choi
- Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - SeungDo Ahn
- Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sang-Wook Lee
- Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - JungWon Kwak
- Departments of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| |
Collapse
|
43
|
Dosimetric evaluation of respiratory gated volumetric modulated arc therapy for lung stereotactic body radiation therapy using 3D printing technology. PLoS One 2018; 13:e0208685. [PMID: 30586367 PMCID: PMC6306268 DOI: 10.1371/journal.pone.0208685] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 11/22/2018] [Indexed: 02/07/2023] Open
Abstract
Purpose This study aimed to evaluate the dosimetric accuracy of respiratory gated volumetric modulated arc therapy (VMAT) for lung stereotactic body radiation therapy (SBRT) under simulation conditions similar to the actual clinical situation using patient-specific lung phantoms and realistic target movements. Methods Six heterogeneous lung phantoms were fabricated using a 3D-printer (3DISON, ROKIT, Seoul, Korea) to be dosimetrically equivalent to actual target regions of lung SBRT cases treated via gated VMAT. They were designed to move realistically via a motion device (QUASAR, Modus Medical Devices, Canada). Using the lung phantoms and a homogeneous phantom (model 500–3315, Modus Medical Devices), film dosimetry was performed with and without respiratory gating for VMAT delivery (TrueBeam STx; Varian Medical Systems, Palo Alto, CA, USA). The measured results were analyzed with the gamma passing rates (GPRs) of 2%/1 mm criteria, by comparing with the calculated dose via the AXB and AAA algorithms of the Eclipse Treatment Planning System (version 10.0.28; Varian Medical Systems). Results GPRs were greater than the acceptance criteria 80% for all film measurements with the stationary and homogeneous phantoms in conventional QAs. Regardless of the heterogeneity of phantoms, there were no significant differences (p > 0.05) in GPRs obtained with and without target motions; the statistical significance (p = 0.031) was presented between both algorithms under the utilization of heterogeneous phantoms. Conclusions Dosimetric verification with heterogeneous patient-specific lung phantoms could be successfully implemented as the evaluation method for gated VMAT delivery. In addition, it could be dosimetrically confirmed that the AXB algorithm improved the dose calculation accuracy under patient-specific simulations using 3D printed lung phantoms.
Collapse
|
44
|
Park SY, Kim JI, Chun M, Ahn H, Park JM. Assessment of the modulation degrees of intensity-modulated radiation therapy plans. Radiat Oncol 2018; 13:244. [PMID: 30545396 PMCID: PMC6293636 DOI: 10.1186/s13014-018-1193-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 11/27/2018] [Indexed: 11/23/2022] Open
Abstract
Background To evaluate the modulation indices (MIs) for predicting the plan delivery accuracies of intensity-modulated radiation therapy (IMRT) plans. Methods A total of 100 dynamic IMRT plans that used TrueBeam STx and 102 dynamic IMRT plans that used Trilogy were selected. For each plan, various MIs were calculated, which included the modulation complexity score (MCS), plan-averaged beam area (PA), plan-averaged beam irregularity (PI), plan-averaged beam modulation (PM), MI quantifying multi-leaf collimator (MLC) speeds (MIs), MI quantifying MLC acceleration (MIa), and MI quantifying MLC acceleration and segment aperture irregularity (MIc,IMRT). To determine plan delivery accuracy, global gamma passing rates, MLC errors of log files, and dose-volumetric parameter differences between original and log file-reconstructed IMRT plans were obtained. To assess the ability of each MI for predicting plan delivery accuracy, Spearman’s rank correlation coefficients (rs) between MIs and plan delivery accuracy measures were calculated. Results PI showed moderately strong correlations with gamma passing rates in MapCHECK2 measurements of both TrueBeam STx and Trilogy (rs = − 0.591 with p < 0.001 and − 0.427 with p < 0.001 to with gamma criterion of 2%/2 mm, respectively). For ArcCHECK measurements, PI also showed moderately strong correlations with the gamma passing rates in the ArcCHECK measurements of TrueBeam STx and Trilogy (rs = − 0.545 with p < 0.001 and rs = − 0.581 with p < 0.001 with gamma criterion of 2%/2 mm, respectively). The PI showed the second strongest correlation with MLC errors in both TrueBeam STx and Trilogy (rs = 0.861 with p < 0.001 and rs = 0.767 with p < 0.001, respectively). In general, the PI showed moderately strong correlations with every plan delivery accuracy measure. Conclusions The PI showed moderately strong correlations with every plan delivery accuracy measure and therefore is a useful predictor of IMRT delivery accuracy. Electronic supplementary material The online version of this article (10.1186/s13014-018-1193-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- So-Yeon Park
- Department of Radiation Oncology, Veterans Health Service Medical Center, Seoul, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Jung-In Kim
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.,Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.,Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Minsoo Chun
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.,Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.,Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyunjun Ahn
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.,Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.,Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jong Min Park
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea. .,Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea. .,Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea. .,Institute for Smart System, Robotics Research Laboratory for Extreme Environments, Advanced Institutes of Convergence Technology, Suwon, Republic of Korea.
| |
Collapse
|
45
|
Knybel L, Penhaker M, Proto A, Otahal B, Nowakova J, Cvek J, Filipova B, Selamat A. Accuracy analysis of the dose delivery process while using the Xsight® Spine Tracking technology. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aae8d7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
46
|
Pogue BW, Wilson BC. Optical and x-ray technology synergies enabling diagnostic and therapeutic applications in medicine. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-17. [PMID: 30350489 PMCID: PMC6197862 DOI: 10.1117/1.jbo.23.12.121610] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 09/24/2018] [Indexed: 05/10/2023]
Abstract
X-ray and optical technologies are the two central pillars for human imaging and therapy. The strengths of x-rays are deep tissue penetration, effective cytotoxicity, and the ability to image with robust projection and computed-tomography methods. The major limitations of x-ray use are the lack of molecular specificity and the carcinogenic risk. In comparison, optical interactions with tissue are strongly scatter dominated, leading to limited tissue penetration, making imaging and therapy largely restricted to superficial or endoscopically directed tissues. However, optical photon energies are comparable with molecular energy levels, thereby providing the strength of intrinsic molecular specificity. Additionally, optical technologies are highly advanced and diversified, being ubiquitously used throughout medicine as the single largest technology sector. Both have dominant spatial localization value, achieved with optical surface scanning or x-ray internal visualization, where one often is used with the other. Therapeutic delivery can also be enhanced by their synergy, where radio-optical and optical-radio interactions can inform about dose or amplify the clinical therapeutic value. An emerging trend is the integration of nanoparticles to serve as molecular intermediates or energy transducers for imaging and therapy, requiring careful design for the interaction either by scintillation or Cherenkov light, and the nanoscale design is impacted by the choices of optical interaction mechanism. The enhancement of optical molecular sensing or sensitization of tissue using x-rays as the energy source is an important emerging field combining x-ray tissue penetration in radiation oncology with the molecular specificity and packaging of optical probes or molecular localization. The ways in which x-rays can enable optical procedures, or optics can enable x-ray procedures, provide a range of new opportunities in both diagnostic and therapeutic medicine. Taken together, these two technologies form the basis for the vast majority of diagnostics and therapeutics in use in clinical medicine.
Collapse
Affiliation(s)
- Brian W. Pogue
- Dartmouth College, Thayer School of Engineering, Geisel School of Medicine, Hanover, New Hampshire, United States
| | - Brian C. Wilson
- University of Toronto, Princess Margaret Cancer Centre/University Health Network, Toronto, Ontario, Canada
| |
Collapse
|
47
|
Park JM, Kim JI, Park SY, Oh DH, Kim ST. Reliability of the gamma index analysis as a verification method of volumetric modulated arc therapy plans. Radiat Oncol 2018; 13:175. [PMID: 30217163 PMCID: PMC6137931 DOI: 10.1186/s13014-018-1123-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/31/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We investigate the gamma passing rate (GPR) consistency when applying different types of gamma analyses, linacs, and dosimeters for volumetric modulated arc therapy (VMAT). METHODS A total of 240 VMAT plans for various treatment sites, which were generated with Trilogy (140 plans) and TrueBeam STx (100 plans), were retrospectively selected. For each VMAT plan, planar dose distributions were measured with both MapCHECK2 and ArcCHECK dosimeters. During the planar dose distribution measurements, the actual multileaf collimator (MLC) positions, gantry angles, and delivered monitor units were recorded and compared to the values in the original VMAT plans to calculate mechanical errors. For each VMAT plan, both the global and local gamma analyses were performed with 3%/3 mm, 2%/2 mm, 2%/1 mm, 1%/2 mm, and 1%/1 mm. The Pearson correlation coefficients (r) were calculated 1) between the global and the local GPRs, 2) between GPRs with the MapCHECK2 and the ArcCHECK dosimeters, 3) and between GPRs and the mechanical errors during the VMAT delivery. RESULTS For the MapCHECK2 measurements, strong correlations between the global and local GPRs were observed only with 1%/2 mm and 1%/1 mm (r > 0.8 with p < 0.001), while weak or no correlations were observed for the ArcCHECK measurement. Between the MapCHECK2 and ArcCHECK measurements, the global GPRs showed no correlations (all with p > 0.05), while the local GPRs showed moderate correlations only with 2%/1 mm and 1%/1 mm for TrueBeam STx (r > 0.5 with p < 0.001). Both the global and local GPRs always showed weak or no correlations with the MLC positional errors except for the GPRs of MapCHECK2 with 1%/2 mm and 1%/1 mm for TrueBeam STx and the GPR of ArcCHECK with 1%/2 mm for Trilogy (r < - 0.5 with p < 0.001). CONCLUSIONS The GPRs varied according to the types of gamma analyses, dosimeters, and linacs. Therefore, each institution should carefully establish their own gamma analysis protocol by determining the type of gamma index analysis and the gamma criterion with their own linac and their own dosimeter.
Collapse
Affiliation(s)
- Jong Min Park
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, South Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, South Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea.,Institute for Smart System, Robotics Research Laboratory for Extreme Environments, Advanced Institutes of Convergence Technology, Suwon, South Korea
| | - Jung-In Kim
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, South Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, South Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
| | - So-Yeon Park
- Department of Radiation Oncology, Veterans Health Service Medical Center, Seoul, South Korea
| | - Do Hoon Oh
- Department of Radiation Oncology, Myongji Hospital, Goyang, South Korea.
| | - Sang-Tae Kim
- Nuclear Emergency Division, Radiation Protection and Emergency Preparedness Bureau, Nuclear Safety and Security Commission, Seoul, South Korea.
| |
Collapse
|
48
|
Zhang D, Wang B, Zhang G, Ma C, Deng X. Comparison of 3D and 2D gamma passing rate criteria for detection sensitivity to IMRT delivery errors. J Appl Clin Med Phys 2018; 19:230-238. [PMID: 29905004 PMCID: PMC6036388 DOI: 10.1002/acm2.12389] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/07/2018] [Accepted: 05/24/2018] [Indexed: 11/11/2022] Open
Abstract
This study compared three‐dimensional (3D) and two‐dimensional (2D) percentage gamma passing rates (%GPs) for detection sensitivity to IMRT delivery errors and investigated the correlation between two kinds of %GP. Eleven prostate IMRT cases were selected, and errors in multileaf collimator (MLC) bank sag, MLC leaf traveling, and machine output were simulated by recalculating the dose distributions in patients. 2D doses were extracted from the 3D doses at the isocenter position. The 3D and 2D %GPs with different gamma criteria were then obtained by comparing the recalculated and original doses in specific regions of interest (ROI), such as the whole body, the planning target volume (PTV), the bladder, and the rectum. The sensitivities to simulated errors of the two types of %GP were compared, and the correlation between the 2D and 3D %GPs for different ROIs were analyzed. For the whole‐body evaluation, both the 2D and 3D %GPs with the 3%/3 mm criterion were above 90% for all tested MLC errors and for MU deviations up to 4%, and the 3D %GP was higher than the 2D %GP. In organ‐specific evaluations, the PTV‐specific 2D and 3D %GP gradients were −4.70% and −5.14% per millimeter of the MLC traveling error, and −17.79% and −20.50% per percentage of MU error, respectively. However, a stricter criterion (2%/1 mm) was needed to detect the tested MLC sag error. The Pearson correlation analysis showed a significant strong correlation (r > 0.8 and P < 0.001) between the 2D and 3D %GPs in the whole body and PTV‐specific gamma evaluations. The whole‐body %GP with the 3%/3 mm criterion was inadequate to detect the tested MLC and MU errors, and a stricter criterion may be needed. The PTV‐specific gamma evaluation helped to improve the sensitivity of the error detection, especially using the 3D GP%.
Collapse
Affiliation(s)
- Dandan Zhang
- Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China.,School of Physics, Sun Yat-sen University, Guangzhou, China
| | - Bin Wang
- Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Guangshun Zhang
- Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Charlie Ma
- Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Xiaowu Deng
- Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China.,School of Physics, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
49
|
Kim DS, Kim S, Kang SH, Kim TH, Park SH, Kim KH, Cho MS, Shin DS, Noh YY, Chung JB, Suh TS. To propose adding index of achievement (IOA) to IMRT QA process. Radiat Oncol 2018; 13:112. [PMID: 29903025 PMCID: PMC6003087 DOI: 10.1186/s13014-018-1055-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/28/2018] [Indexed: 11/28/2022] Open
Abstract
Background In intensity modulated radiation therapy (IMRT) quality assurance (QA), evaluation of QA result using a pass/non-pass strategy under an acceptance criterion often suffers from lack of information on how good the plan is in absolute manner. In this study, we suggested adding an index system, previously developed for dose painting technique, to current IMRT QA process for better understanding of QA result. Methods The index system consists of three indices, index of achievement (IOA), index of hotness (IOH) and index of coldness (IOC). As indicated by its name, IOA does measure the level of agreement. IOH and IOC, on the other hand, measure the magnitude of overdose and underdose, respectively. A systematic analysis was performed with three 1-dimensional hypothetical dose distributions to investigate the characteristics of the index system. The feasibility of the system was also assessed with clinical volumetric modulated arc therapy (VMAT) QA cases from 8 head & neck and 5 prostate patients. In both simulation studies, certain amount of errors was intentionally induced to each dose distribution. Furthermore, we applied the proposed system to compare calculated with actual measured data for a total of 60 patients (30 head & neck and 30 prostate cases). QA analysis was made using both the index system and gamma method, and results were compared. Results While the gamma evaluation showed limited sensitivity in evaluating QA result depending on the level of tolerance criteria used, the proposed indices tended to better distinguish plans in terms of the amount of errors. Hotness and coldness of prescribed dose in the plan could be evaluated quantitatively by the indices. Conclusions The proposed index system provides information with which IMRT QA result would be better evaluated, especially when gamma pass rates are identical or similar among multiple plans. In addition, the independency of the index system on acceptance criteria would help making clear communications among readers of published articles and researchers in multi-institutional studies.
Collapse
Affiliation(s)
- Dong-Su Kim
- Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, 222. Banpo-daero, Seocho-gu, Seoul, 06591, South Korea
| | - Siyong Kim
- Department of Radiation Oncology, Virginia Commonwealth University, 401 College Street, Richmond, VA, 23298-0058, USA.
| | - Seong-Hee Kang
- Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, 222. Banpo-daero, Seocho-gu, Seoul, 06591, South Korea.,Department of Radiation Oncology, Seoul National University Bundang Hospital, Gumi-ro 173 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, South Korea
| | - Tae-Ho Kim
- Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, 222. Banpo-daero, Seocho-gu, Seoul, 06591, South Korea
| | - So-Hyun Park
- Department of Radiation Oncology, Jeju National University Hospital, 15, Aran 13-gil, Jeju-si, Jeju-do, 63241, South Korea
| | - Kyeong-Hyeon Kim
- Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, 222. Banpo-daero, Seocho-gu, Seoul, 06591, South Korea
| | - Min-Seok Cho
- Department of Radiation Oncology, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Dong-Seok Shin
- Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, 222. Banpo-daero, Seocho-gu, Seoul, 06591, South Korea
| | - Yu-Yun Noh
- Department of Radiation Oncology, Eulji University Hospital, 95, Dunsanseo-ro, Seo-gu, Daejeon, 35233, South Korea
| | - Jin-Beom Chung
- Department of Radiation Oncology, Seoul National University Bundang Hospital, Gumi-ro 173 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, South Korea
| | - Tae Suk Suh
- Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, 222. Banpo-daero, Seocho-gu, Seoul, 06591, South Korea.
| |
Collapse
|
50
|
Alharthi T, Pogson EM, Arumugam S, Holloway L, Thwaites D. Pre-treatment verification of lung SBRT VMAT plans with delivery errors: Toward a better understanding of the gamma index analysis. Phys Med 2018; 49:119-128. [DOI: 10.1016/j.ejmp.2018.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/06/2018] [Accepted: 04/04/2018] [Indexed: 12/31/2022] Open
|