1
|
Tarek I, Hafez A, Fathy MM, Fahmy HM, Abdelaziz DM. Efficacy of flattening filter-free beams with the acuros XB algorithm in thoracic spine stereotactic body radiation therapy. Med Dosim 2024:S0958-3947(24)00005-0. [PMID: 38336567 DOI: 10.1016/j.meddos.2024.01.005] [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: 07/30/2023] [Revised: 12/25/2023] [Accepted: 01/06/2024] [Indexed: 02/12/2024]
Abstract
This study aimed to determine the dosimetric value of flattening filter-free (FFF) beams compared to flattening filter (FF) beams using different algorithms in the treatment planning of thoracic spine stereotactic body radiation therapy (SBRT). A total of 120 plans were created for 15 patients using the Anisotropic Analytical Algorithm (AAA) and the Acuros External Beam (AXB) algorithm with FF and FFF beams at 6 MV and 10 MV energies. Various dosimetric parameters were evaluated, including target coverage, dose spillage, and organs-at-risk sparing of the spinal cord and esophagus. Treatment delivery parameters, such as the monitor units (MUs), modulation factors (MFs), beam-on time (BOT), and dose calculation time (DCT), were also collected. Significant differences were observed in the dosimetric parameters when AXB was used for all energies (P < 0.05). 6 XFFF energy was the best option for target coverage, dose spillage, and organs-at-risk sparing. In contrast, dosimetric parameters had no significant difference when using the AAA. The AAA and AXB calculations showed that the 6 XFFF beam had the shortest DCT. The treatment delivery parameters indicated that 10 XFF beam required the fewest MUs and MFs. In addition, the 10 XFFF beam demonstrated the shortest BOT. For effective treatment of the thoracic spine using SBRT, it is recommended to use the 10 XFFF beam because of the short BOT. Moreover, the AXB algorithm should be used because of its accurate dose calculation in regions with tissue heterogeneity.
Collapse
Affiliation(s)
- Islam Tarek
- Department of Biophysics, Faculty of Science, Cairo University, Cairo, Egypt; Department of Radiotherapy, Baheya center for early detection and treatment of breast cancer, Giza, Egypt.
| | - Abdelrahman Hafez
- Department of Radiotherapy, Baheya center for early detection and treatment of breast cancer, Giza, Egypt
| | - Mohamed M Fathy
- Department of Biophysics, Faculty of Science, Cairo University, Cairo, Egypt.
| | - Heba M Fahmy
- Department of Biophysics, Faculty of Science, Cairo University, Cairo, Egypt
| | - Dina M Abdelaziz
- Department of Radiotherapy, Baheya center for early detection and treatment of breast cancer, Giza, Egypt; Department of Radiotherapy, National cancer institute, Cairo University, Cairo, Egypt
| |
Collapse
|
2
|
Hirashima H, Nakamura M, Nakamura K, Matsuo Y, Mizowaki T. Dosimetric verification of four dose calculation algorithms for spine stereotactic body radiotherapy. JOURNAL OF RADIATION RESEARCH 2024; 65:109-118. [PMID: 37996097 PMCID: PMC10803157 DOI: 10.1093/jrr/rrad086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/18/2023] [Accepted: 10/16/2023] [Indexed: 11/25/2023]
Abstract
The applications of Type B [anisotropic analytical algorithm (AAA) and collapsed cone (CC)] and Type C [Acuros XB (AXB) and photon Monte Carlo (PMC)] dose calculation algorithms in spine stereotactic body radiotherapy (SBRT) were evaluated. Water- and bone-equivalent phantoms were combined to evaluate the percentage depth dose and dose profile. Subsequently, 48 consecutive patients with clinical spine SBRT plans were evaluated. All treatment plans were created using AXB in Eclipse. The prescription dose was 24 Gy in two fractions at a 10 MV FFF on TrueBeam. The doses were then recalculated with AAA, CC and PMC while maintaining the AXB-calculated monitor units and beam arrangement. The dose index values obtained using the four dose calculation algorithms were then compared. The AXB and PMC dose distributions agreed with the bone-equivalent phantom measurements (within ±2.0%); the AAA and CC values were higher than those in the bone-equivalent phantom region. For the spine SBRT plans, PMC, AAA and CC were overestimated compared with AXB in terms of the near minimum and maximum doses of the target and organ at risk, respectively; the mean dose difference was within 4.2%, which is equivalent with within 1 Gy. The phantom study showed that the results from AXB and PMC agreed with the measurements within ±2.0%. However, the mean dose difference ranged from 0.5 to 1 Gy in the spine SBRT planning study when the dose calculation algorithms changed. Users should incorporate a clinical introduction that includes an awareness of these differences.
Collapse
Affiliation(s)
- Hideaki Hirashima
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Mitsuhiro Nakamura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
- Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kiyonao Nakamura
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Yukinori Matsuo
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| |
Collapse
|
3
|
He C, Pant A, Le AH. Impact of the Acuros XB spatial discretization error on ArcCHECK VMAT QA for small-field SBRT. J Appl Clin Med Phys 2023; 24:e14100. [PMID: 37563870 PMCID: PMC10476976 DOI: 10.1002/acm2.14100] [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: 02/03/2023] [Revised: 04/26/2023] [Accepted: 06/27/2023] [Indexed: 08/12/2023] Open
Abstract
PURPOSE To evaluate the impact of the Acuros XB spatial discretization errors on ArcCHECK volumetric modulated arc therapy (VMAT) QA for small-field SBRT plans. METHODS Eighteen SBRT VMAT arcs that failed the ArcCHECK VMAT QA were retrospectively analyzed. Plan verification doses were calculated using Eclipse Acuros XB, and absolute 3%/2 mm gamma passing rates were calculated to compare ArcCHECK and MapCHECK2 with MapPHAN. Verification doses were recalculated using AAA in Eclipse and with the EGSnrc Monte Carlo package. In addition, error-reduced Acuros XB doses were calculated by subdividing the entire arc into several sub-arcs ("split-arc" method), with the angular ranges of the sub-arcs optimized to balance accuracy and efficiency. Relative gamma passing rates were calculated and compared for the four methods: (1) Acuros XB; (2) AAA; (3) EGSnrc Monte Carlo; and (4) the split-arc method. RESULTS The absolute gamma passing rates were below 90% for ArcCHECK and above 95% for MapCHECK2. The averaged relative gamma passing rates were (1) 84.7% for clinical Acuros XB; (2) 96.8% for AAA; (3) 98.8% for EGSnrc Monte Carlo; and (4) 96.8% for the split-arc method with 60° sub-arc angle. Compared to the clinical Acuros XB, the split-arc method improved the relative gamma passing rate by 12.1% on average. No significant difference was found between AAA and the split-arc method (p > 0.05). CONCLUSION The Acuros XB spatial discretization errors can significantly impact the ArcCHECK VMAT QA results for small-field SBRT plans. The split-arc method may be used to improve the VMAT QA results.
Collapse
Affiliation(s)
- Chuan He
- Roswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
- University at BuffaloThe State University of New YorkBuffaloNew YorkUSA
| | - Ankit Pant
- Roswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
- University at BuffaloThe State University of New YorkBuffaloNew YorkUSA
| | - Anh H. Le
- University at BuffaloThe State University of New YorkBuffaloNew YorkUSA
- Department of Radiation OncologyCedars‐Sinai Medical CenterLos AngelesCaliforniaUSA
| |
Collapse
|
4
|
Rostami A, Neto AJDC, Paloor SP, Khalid AS, Hammoud R. Comparison of four commercial dose calculation algorithms in different evaluation tests. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2023; 31:1013-1033. [PMID: 37393487 DOI: 10.3233/xst-230079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/03/2023]
Abstract
BACKGROUND Accurate and fast dose calculation is crucial in modern radiation therapy. Four dose calculation algorithms (AAA, AXB, CCC, and MC) are available in Varian Eclipse and RaySearch Laboratories RayStation Treatment Planning Systems (TPSs). OBJECTIVES This study aims to evaluate and compare dosimetric accuracy of the four dose calculation algorithms applying to homogeneous and heterogeneous media, VMAT plans (based on AAPM TG-119 test cases), and the surface and buildup regions. METHODS The four algorithms are assessed in homogeneous (IAEA-TECDOCE 1540) and heterogeneous (IAEA-TECDOC 1583) media. Dosimetric evaluation accuracy for VMAT plans is then analyzed, along with the evaluation of the accuracy of algorithms applying to the surface and buildup regions. RESULTS Tests conducted in homogeneous media revealed that all algorithms exhibit dose deviations within 5% for various conditions, with pass rates exceeding 95% based on recommended tolerances. Additionally, the tests conducted in heterogeneous media demonstrate high pass rates for all algorithms, with a 100% pass rate observed for 6 MV and mostly 100% pass rate for 15 MV, except for CCC, which achieves a pass rate of 94%. The results of gamma index pass rate (GIPR) for dose calculation algorithms in IMRT fields show that GIPR (3% /3 mm) for all four algorithms in all evaluated tests based on TG119, are greater than 97%. The results of the algorithm testing for the accuracy of superficial dose reveal variations in dose differences, ranging from -11.9% to 7.03% for 15 MV and -9.5% to 3.3% for 6 MV, respectively. It is noteworthy that the AXB and MC algorithms demonstrate relatively lower discrepancies compared to the other algorithms. CONCLUSIONS This study shows that generally, two dose calculation algorithms (AXB and MC) that calculate dose in medium have better accuracy than other two dose calculation algorithms (CCC and AAA) that calculate dose to water.
Collapse
Affiliation(s)
- Aram Rostami
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| | | | - Satheesh Prasad Paloor
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| | - Abdul Sattar Khalid
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| | - Rabih Hammoud
- Radiation Oncology Department, National Center for Cancer Care and Research, Doha, Qatar
| |
Collapse
|
5
|
Saglam Y, Selek U, Bolukbasi Y. A novel and clinically useful weight-optimized dynamic conformal arc in stereotactic radiation therapy of non-small cell lung cancer: Dosimetric comparison of treatment plans with volumetric‐modulated arc therapy. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110623] [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]
|
6
|
Gopalakrishnan Z, Bhasi S, P R, Menon SV, B S, Thayil AG, Nair RK. Dosimetric comparison of analytical anisotropic algorithm and the two dose reporting modes of Acuros XB dose calculation algorithm in volumetric modulated arc therapy of carcinoma lung and carcinoma prostate. Med Dosim 2022; 47:280-287. [PMID: 35690544 DOI: 10.1016/j.meddos.2022.04.007] [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: 12/10/2021] [Revised: 03/18/2022] [Accepted: 04/21/2022] [Indexed: 10/18/2022]
Abstract
Volumetric Modulated Arc Therapy (VMAT) is an important modality for radical radiotherapy of all major treatment sites. This study aims to compare Analytical Anisotropic Algorithm (AAA) and the two dose-reporting modes of Acuros XB (AXB) algorithm -the dose to medium option (Dm) and the dose to water option (Dw) in Volumetric Modulated Arc Therapy (VMAT) of carcinoma lung and carcinoma prostate. We also compared the measured dose with Treatment Planning System calculated dose for AAA and the two dose reporting options of Acuros XB using Electronic Portal Imaging Device (EPID) and ArcCHECK phantom. Treatment plans of twenty patients each who have already undergone radiotherapy for cancer of lung and cancer of prostate were selected for the study. Three sets of VMAT plans were generated in Eclipse Treatment Planning System (TPS), one with AAA and two plans with Acuros-Dm and Acuros-Dw options. The Dose Volume Histograms (DVHs) were compared and analyzed for Planning Target Volume (PTV) and critical structures for all the plans. Verification plans were created for each plan and measured doses were compared with TPS calculated doses using EPID and ArcCHECK phantom for all the three algorithms. For lung plans, the mean dose to PTV in the AXB-Dw plans was higher by 1.7% and in the AXB-Dm plans by 0.66% when compared to AAA plans. For prostate plans, the mean dose to PTV in the AXB-Dw plans was higher by 3.0% and in the AXB-Dm plans by 1.6% when compared to AAA plans. There was no difference in the Conformity Index (CI) between AAA and AXB-Dm and between AAA and AXB-Dw plans for both sites. But the homogeneity worsened in AXB-Dw and AXB-Dm plans when compared to AAA plans for both sites. AXB-Dw calculated higher dose values for PTV and all the critical structures with significant differences with one or two exceptions. Point dose measurements in ArcCHECK phantom showed that AXB-Dm and AXB-Dw options showed very small deviations with measured dose distributions than AAA for both sites. Results of EPID QA also showed better pass rates for AXB-Dw and AXB-Dm than AAA for both sites when gamma analysis was done for 3%/3 mm and 2%/2 mm criteria. With reference to the results, it is always better to choose Acuros algorithm for dose calculations if it is available in the TPS. AXB-Dw plans showed very high dose values in the PTV when compared to AAA and AXB-Dm in both sites studied. Also, the volume of PTV receiving 107% dose was significantly high in AXB-Dw plans compared to AXB-Dm plans in sites involving high density bones. Considering the results of dosimetric comparison and QA measurements, it is always better to choose AXB-Dm algorithm for dose calculations for all treatment sites especially when high density bony structures and complex treatment techniques are involved. For patient specific QA purposes, choosing AXB-Dm or AXB-Dw does not make any significant difference between calculated and measured dose distributions.
Collapse
Affiliation(s)
- Zhenia Gopalakrishnan
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala 695011, India
| | - Saju Bhasi
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala 695011, India
| | - Raghukumar P
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala 695011, India.
| | - Sharika V Menon
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala 695011, India
| | - Sarin B
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala 695011, India
| | - Anna George Thayil
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala 695011, India
| | - Raghuram K Nair
- SUT Royal Hospital, Ulloor, Thiruvananthapuram, Kerala 695011, India
| |
Collapse
|
7
|
Banaei A, Hashemi B, Bakhshandeh M. Estimating cancer risks due to whole lungs low dose radiotherapy with different techniques for treating COVID-19 pneumonia. Radiat Oncol 2022; 17:10. [PMID: 35057839 PMCID: PMC8771186 DOI: 10.1186/s13014-021-01971-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 12/20/2021] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Low dose radiotherapy (LDRT) of whole lungs with photon beams is a novel method for treating COVID-19 pneumonia. This study aimed to estimate cancer risks induced by lung LDRT for different radiotherapy delivery techniques. METHOD Four different radiotherapy techniques, including 3D-conformal with anterior and posterior fields (3D-CRT AP-PA), 3D-conformal with 8 coplanar fields (3D-CRT 8 fields), eight fields intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy using 2 full arcs (VMAT) were planned on the CT images of 32 COVID-19 patients with the prescribed dose of 1 Gy to the lungs. Organ average and maximum doses, and PTV dose distribution indexes were compared between different techniques. The radiation-induced cancer incidence and cancer-specific mortality, and cardiac heart disease risks were estimated for the assessed techniques. RESULTS In IMRT and VMAT techniques, heart (mean and max), breast (mean, and max), and stomach (mean) doses and also maximum dose in the body were significantly lower than the 3D-CRT techniques. The calculated conformity indexes were similar in all the techniques. However, the homogeneity indexes were lower (i.e., better) in intensity-modulated techniques (P < 0.03) with no significant differences between IMRT and VMAT plans. Lung cancer incident risks for all the delivery techniques were similar (P > 0.4). Cancer incidence and mortality risks for organs located closer to lungs like breast and stomach were higher in 3D-CRT techniques than IMRT or VMAT techniques (excess solid tumor cancer incidence risks for a 30 years man: 1.94 ± 0.22% Vs. 1.68 ± 0.17%; and women: 6.66 ± 0.81% Vs. 4.60 ± 0.43%: cancer mortality risks for 30 years men: 1.63 ± 0.19% Vs. 1.45 ± 0.15%; and women: 3.63 ± 0.44% Vs. 2.94 ± 0.23%). CONCLUSION All the radiotherapy techniques had low cancer risks. However, the overall estimated risks induced by IMRT and VMAT radiotherapy techniques were lower than the 3D-CRT techniques and can be used clinically in younger patients or patients having greater concerns about radiation induced cancers.
Collapse
Affiliation(s)
- Amin Banaei
- Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Al-Ahmad and Chamran Cross, 1411713116 Tehran, Iran
| | - Bijan Hashemi
- Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Al-Ahmad and Chamran Cross, 1411713116 Tehran, Iran
| | - Mohsen Bakhshandeh
- Department of Radiology Technology, Faculty of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| |
Collapse
|
8
|
Hardcastle N, Hughes J, Siva S, Kron T. Dose calculation and reporting with a linear Boltzman transport equation solver in vertebral SABR. Phys Eng Sci Med 2021; 45:43-48. [PMID: 34813052 DOI: 10.1007/s13246-021-01076-1] [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: 03/27/2021] [Accepted: 11/05/2021] [Indexed: 11/29/2022]
Abstract
Vertebral Stereotactic ablative body radiotherapy (SABR) involves substantial tumour density heterogeneities. We evaluated the impact of a linear Boltzmann transport equation (LBTE) solver dose calculation on vertebral SABR dose distributions. A sequential cohort of 20 patients with vertebral metastases treated with SABR were selected. Treatment plans were initially planned with a convolution style dose calculation algorithm. The plan was copied and recalculated with a LBTE algorithm reporting both dose to water (Dw) or dose to medium (Dm). Target dose as a function of CT number, and spinal cord dose was compared between algorithms. Compared with a convolution algorithm, there was minimal change in PTV D90% with LBTE. LBTE reporting Dm resulted in reduced GTV D50% by (mean, 95% CI) 2.2% (1.9-2.6%) and reduced Spinal Cord PRV near-maximum dose by 3.0% (2.0-4.1%). LBTE reporting Dw resulted in increased GTV D50% by 2.4% (1.8-3.0%). GTV D50% decreased or increased with increasing CT number with Dm or Dw respectively. LBTE, reporting either Dm or Dw resulted in decreased central spinal cord dose by 8.7% (7.1-10.2%) and 7.2% (5.7-8.8%) respectively. Reported vertebral SABR tumour dose when calculating with an LBTE algorithm depends on tumour density. Spinal cord near-maximum dose was lower when using LBTE algorithm reporting Dm, which may result in higher spinal cord doses being delivered than with a convolution style algorithm. Spinal cord central dose was significantly lower with LBTE, potentially reflecting LBTE transport approximations.
Collapse
Affiliation(s)
- Nicholas Hardcastle
- Physical Sciences, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3012, Australia. .,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia. .,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia.
| | - Jeremy Hughes
- Physical Sciences, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3012, Australia
| | - Shankar Siva
- Physical Sciences, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3012, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Tomas Kron
- Physical Sciences, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC, 3012, Australia.,Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia.,Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| |
Collapse
|
9
|
Menon SV, P R, Bhasi S, Gopalakrishnan Z, B S, K S, Nair RK. Dosimetric comparison and validation of Eclipse Anisotropic Analytical Algorithm (AAA) and AcurosXB (AXB) algorithms in RapidArc-based radiosurgery plans of patients with solitary brain metastasis. Med Dosim 2021; 47:e7-e12. [PMID: 34740518 DOI: 10.1016/j.meddos.2021.09.001] [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: 05/28/2021] [Revised: 08/02/2021] [Accepted: 09/01/2021] [Indexed: 11/28/2022]
Abstract
Stereotactic radiosurgery (SRS) is increasingly being used to manage solitary or multiple brain metastasis. This study aims to compare and validate Anisotropic Analytical Algorithm (AAA) and AcurosXB (AXB) algorithms of Eclipse Treatment Planning System (TPS) in RapidArc-based SRS plans of patients with solitary brain metastasis. Twenty patients with solitary brain metastasis who have been already treated with RapidArc SRS plans calculated using AAA plans were selected for this study. These plans were recalculated using AXB algorithm keeping the same arc orientations, multi-leaf collimator apertures, and monitor units. The two algorithms were compared for target coverage parameters, isodose volumes, plan quality metrics, dose to organs at risk and integral dose. The dose calculated by the TPS using AAA and AXB algorithms was validated against measured dose for all patient plans using an in-house developed cylindrical phantom. An Exradin A14SL ionization chamber was positioned at the center of this phantom to measure the in-field dose. NanoDot Optically Stimulated Luminescent Dosimeters (OSLDs) (Landauer Inc.) were placed at distances 3.0 cm, 4.0 cm, 5.0 cm, and 6.0 cm respectively from the center of the phantom to measure the non-target dose. In addition, the planar dose distribution was measured using amorphous silicon aS1000 Electronic Portal Imaging Device. The measured 2D dose distribution was compared against AAA and AXB estimated 2D distribution using gamma analysis. All results were tested for significance using the paired t-test at 5% level of significance. Significant differences between the AAA and AXB plans were found only for a few parameters analyzed in this study. In the experimental verification using cylindrical phantom, the difference between the AAA calculated dose and the measured dose was found to be highly significant (p < 0.001). However, the difference between the AXB calculated dose and the measured dose was not significant (p = 0.197). The difference between AAA/AXB calculated and measured at non-target locations was statistically insignificant at all four non-target locations and the dose calculated by both AAA and AXB algorithms shows a strong positive correlation with the measured dose. The results of the gamma analysis show that the AXB calculated planar dose is in better agreement with measurements compared to the AAA. Even though the results of the dosimetric comparison show that the differences are mostly not significant, the measurements show that there are differences between the two algorithms within the target volume. The AXB algorithm may be therefore more accurate in the dose calculation of VMAT plans for the treatment of small intracranial targets. For non-target locations either algorithm can be used for the estimation of dose accounting for their limitations in non-target dose estimations.
Collapse
Affiliation(s)
- Sharika Venugopal Menon
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala, India; Centre for Research and Evaluation, Bharathiar University, Coimbatore, Tamil Nadu, India
| | - Raghukumar P
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala, India.
| | - Saju Bhasi
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala, India
| | - Zhenia Gopalakrishnan
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala, India
| | - Sarin B
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala, India
| | - Shilpa K
- Division of Radiation Physics, Regional Cancer Centre, Thiruvananthapuram, Kerala, India
| | - Raghuram K Nair
- SUT Royal Hospital, Ulloor, Thiruvananthapuram, Kerala, India
| |
Collapse
|
10
|
Hughes J, Lye JE, Kadeer F, Alves A, Shaw M, Supple J, Keehan S, Gibbons F, Lehmann J, Kron T. Calculation algorithms and penumbra: Underestimation of dose in organs at risk in dosimetry audits. Med Phys 2021; 48:6184-6197. [PMID: 34287963 DOI: 10.1002/mp.15123] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 06/27/2021] [Accepted: 07/07/2021] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The aim of this study is to investigate overdose to organs at risk (OARs) observed in dosimetry audits in Monte Carlo (MC) algorithms and Linear Boltzmann Transport Equation (LBTE) algorithms. The impact of penumbra modeling on OAR dose was assessed with the adjustment of MC modeling parameters and the clinical relevance of the audit cases was explored with a planning study of spine and head and neck (H&N) patient cases. METHODS Dosimetric audits performed by the Australian Clinical Dosimetry Service (ACDS) of 43 anthropomorphic spine plans and 1318 C-shaped target plans compared the planned dose to doses measured with ion chamber, microdiamond, film, and ion chamber array. An MC EGSnrc model was created to simulate the C-shape target case. The electron cut-off energy Ecut(kinetic) was set at 500, 200, and 10 keV, and differences between 1 and 3 mm voxel were calculated. A planning study with 10 patient stereotactic body radiotherapy (SBRT) spine plans and 10 patient H&N plans was calculated in both Acuros XB (AXB) v15.6.06 and Anisotropic Analytical Algorithm (AAA) v15.6.06. The patient contour was overridden to water as only the penumbral differences between the two different algorithms were under investigation. RESULTS The dosimetry audit results show that for the SBRT spine case, plans calculated in AXB are colder than what is measured in the spinal cord by 5%-10%. This was also observed for other audit cases where a C-shape target is wrapped around an OAR where the plans were colder by 3%-10%. Plans calculated with Monaco MC were colder than measurements by approximately 7% with the OAR surround by a C-shape target, but these differences were not noted in the SBRT spine case. Results from the clinical patient plans showed that the AXB was on average 7.4% colder than AAA when comparing the minimum dose in the spinal cord OAR. This average difference between AXB and AAA reduced to 4.5% when using the more clinically relevant metric of maximum dose in the spinal cord. For the H&N plans, AXB was cooler on average than AAA in the spinal cord OAR (1.1%), left parotid (1.7%), and right parotid (2.3%). The EGSnrc investigation also noted similar, but smaller differences. The beam penumbra modeled by Ecut(kinetic) = 500 keV was steeper than the beam penumbra modeled by Ecut(kinetic) = 10 keV as the full scatter is not accounted for, which resulted in less dose being calculated in a central OAR region where the penumbra contributes much of the dose. The dose difference when using 2.5 mm voxels of the center of the OAR between 500 and 10 keV was 3%, reducing to 1% between 200 and 10 keV. CONCLUSIONS Lack of full penumbral modeling due to approximations in the algorithms in MC based or LBTE algorithms are a contributing factor as to why these algorithms under-predict the dose to OAR when the treatment volume is wrapped around the OAR. The penumbra modeling approximations also contribute to AXB plans predicting colder doses than AAA in areas that are in the vicinity of beam penumbra. This effect is magnified in regions where there are many beam penumbras, for example in the spinal cord for spine SBRT cases.
Collapse
Affiliation(s)
- Jeremy Hughes
- Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Victoria, Australia.,Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Jessica Elizabeth Lye
- Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Victoria, Australia.,Physical Sciences, Olivia Newton-John Cancer Wellness Centre, Heidelberg, Victoria, Australia
| | - Fayz Kadeer
- Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Victoria, Australia
| | - Andrew Alves
- Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Victoria, Australia
| | - Maddison Shaw
- Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Victoria, Australia.,Applied Sciences Physics Department, RMIT University, Melbourne, Victoria, Australia
| | - Jeremy Supple
- Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Victoria, Australia
| | - Stephanie Keehan
- Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Victoria, Australia.,Alfred Health Radiation Oncology, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Francis Gibbons
- Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Victoria, Australia.,Physical Sciences, Sunshine Coast University Hospital, Birtinya, Queensland, Australia
| | - Joerg Lehmann
- Applied Sciences Physics Department, RMIT University, Melbourne, Victoria, Australia.,Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, New South Wales, Australia.,School of Mathematical and Physical Sciences, University of Newcastle, Callaghan, New South Wales, Australia.,Institute of Medical Physics, University of Sydney, Camperdown, New South Wales, Australia
| | - Tomas Kron
- Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.,Applied Sciences Physics Department, RMIT University, Melbourne, Victoria, Australia
| |
Collapse
|
11
|
Srivastava RP, Basta K, De Gersem W, De Wagter C. A comparative analysis of Acuros XB and the analytical anisotropic algorithm for volumetric modulation arc therapy. REPORTS OF PRACTICAL ONCOLOGY AND RADIOTHERAPY : JOURNAL OF GREATPOLAND CANCER CENTER IN POZNAN AND POLISH SOCIETY OF RADIATION ONCOLOGY 2021; 26:481-488. [PMID: 34277105 PMCID: PMC8281916 DOI: 10.5603/rpor.a2021.0050] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 02/23/2021] [Indexed: 11/25/2022]
Abstract
Background This study aimed to verify the dosimetric impact of Acuros XB (AXB) (AXB, Varian Medical Systems Palo Alto CA, USA), a two model-based algorithm, in comparison with Anisotropic Analytical Algorithm (AAA ) calculations for prostate, head and neck and lung cancer treatment by volumetric modulated arc therapy (VMAT ), without primary modification to AA. At present, the well-known and validated AA algorithm is clinically used in our department for VMAT treatments of different pathologies. AXB could replace it without extra measurements. The treatment result and accuracy of the dose delivered depend on the dose calculation algorithm. Materials and method Ninety-five complex VMAT plans for different pathologies were generated using the Eclipse version 15.0.4 treatment planning system (TPS). The dose distributions were calculated using AA and AXB (dose-to-water, AXBw and dose-to-medium, AXBm), with the same plan parameters for all VMAT plans. The dosimetric parameters were calculated for each planning target volume (PTV) and involved organs at risk (OA R). The patient specific quality assurance of all VMAT plans has been verified by Octavius®-4D phantom for different algorithms. Results The relative differences among AA, AXBw and AXBm, with respect to prostate, head and neck were less than 1% for PTV D95%. However, PTV D95% calculated by AA tended to be overestimated, with a relative dose difference of 3.23% in the case of lung treatment. The absolute mean values of the relative differences were 1.1 ± 1.2% and 2.0 ± 1.2%, when comparing between AXBw and AA, AXBm and AA, respectively. The gamma pass rate was observed to exceed 97.4% and 99.4% for the measured and calculated doses in most cases of the volumetric 3D analysis for AA and AXBm, respectively. Conclusion This study suggests that the dose calculated to medium using AXBm algorithm is better than AAA and it could be used clinically. Switching the dose calculation algorithm from AA to AXB does not require extra measurements.
Collapse
Affiliation(s)
- Raju P Srivastava
- Radiotherapy Association Meuse Picardie, Centre Hospitalier Mouscron, Mouscron, Belgium.,Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | - K Basta
- Radiotherapy Association Meuse Picardie, Centre Hospitalier Mouscron, Mouscron, Belgium
| | - Werner De Gersem
- Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium.,Department of Radiation Oncology and Experimental Cancer Research, Ghent University, Belgium
| | - Carlos De Wagter
- Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium.,Department of Radiation Oncology and Experimental Cancer Research, Ghent University, Belgium
| |
Collapse
|
12
|
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
|
13
|
Rijken J, Crowe S, Trapp J, Kairn T. A review of stereotactic body radiotherapy for the spine. Phys Eng Sci Med 2020; 43:799-824. [DOI: 10.1007/s13246-020-00889-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 06/11/2020] [Indexed: 12/11/2022]
|
14
|
Akdeniz Y, Yegingil I, Yegingil Z. Effects of metal implants and a metal artifact reduction tool on calculation accuracy of AAA and Acuros XB algorithms in small fields. Med Phys 2019; 46:5326-5335. [PMID: 31508819 DOI: 10.1002/mp.13819] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/28/2019] [Accepted: 09/04/2019] [Indexed: 11/05/2022] Open
Abstract
PURPOSE In this study, the dosimetric accuracy of analytical anisotropic algorithm (AAA) and Acuros XB (AXB) dose calculation algorithms (Varian Medical Systems, Palo Alto, CA) was investigated for small radiation fields incident on phantoms of various metals that include stainless steel grade 316L (SS316L) and titanium alloy grade 5 (Ti5) implants. In addition, the effects of using metal artifact reduction for orthopedic implants (O-MAR, Philips Healthcare, Cleveland, OH) were evaluated. METHODS The evaluations of AAA and AXB were performed by comparing the crossline profiles calculated by AAA and AXB with GafChromicTM EBT3 film measurements at the phantom-implant interfaces and in close vicinity of implant materials for small field sizes (1 × 1 cm2 , 2 × 2 cm2 , 3 × 3 cm2 , and 4 × 4 cm2 ) of a 6 MV flattening filter free photon beam. O-MAR corrected and uncorrected (UC) computed tomography (CT) images were used for dose calculations. The values of average and standard deviations (SD) of Hounsfield unit (HU) for selected regions of each case were evaluated. The differences in average dose percentages in defined regions were calculated to quantify the relative dosimetric changes between doses calculated on UC and O-MAR corrected CT images. RESULTS Compared to UC images, the values of SD were reduced, and the average HU became closer to its reference value in the O-MAR images. There was some discrepancy in average dose percentage differences between calculations using UC and O-MAR images at 1 cm above the SS316L implant (average dose percentage differences were AXB/UC = 5.9% and AXB/O-MAR = -1.2%; AAA/UC = 2.2%, and AAA/O-MAR = -0.8%). Neither AAA nor AXB algorithms predict increase in dose at upper phantom-implant interface (4.9%, 9.9%. 13.5%, and 13.8% for the fields from 1 × 1 cm2 to 4 × 4 cm2 , respectively). At the side of the SS316L implant (where dark streak artifacts exist), dose difference averages were estimated as - 1.1% and 22.3% when AXB/O-MAR and AXB/UC calculations are compared with EBT3 measurements, respectively. Dose predictions at 1 cm below the SS316L implant were underestimated by AXB/O-MAR (average -0.5%) and AXB/UC (average 2.0%). CONCLUSIONS The O-MAR tool was shown to have a favorable dosimetric effect or no effect on the calculations in the upper proximity of the implant materials. The dose differences between EBT3 film measurements and calculations at upper phantom-implant interfaces were smaller when they were calculated using O-MAR images. However, the dose differences increased when O-MAR corrected images were used for AAA calculations at lower phantom-implant interfaces. Use of O-MAR enabled closer agreement for the AXB algorithm, especially in the dark streak artifact regions. The O-MAR algorithm should be used when the dose is calculated with the AXB algorithm in cases of patients with the metal implants. The estimations using AAA and AXB algorithms, in phantom setups, with Ti5 implant material were found to be closer to the EBT3 film measurements, when compared with the same estimations using SS316L implant material.
Collapse
Affiliation(s)
- Yucel Akdeniz
- Department of Radiation Oncology, Acıbadem Adana Hospital, Seyhan, Adana, 01130, Turkey
| | - Ilhami Yegingil
- Department of Electrical and Electronics Engineering, Faculty of Engineering, Hasan Kalyoncu University, Gaziantep, Turkey
| | - Zehra Yegingil
- Department of Physics, Faculty of Science and Letters, Cukurova University, Saricam, Adana, 01330, Turkey
| |
Collapse
|
15
|
Zhang J, Jiang D, Su H, Dai Z, Dai J, Liu H, Xie C, Yu H. Dosimetric comparison of different algorithms in stereotactic body radiation therapy (SBRT) plan for non-small cell lung cancer (NSCLC). Onco Targets Ther 2019; 12:6385-6391. [PMID: 31496740 PMCID: PMC6697670 DOI: 10.2147/ott.s201473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 07/11/2019] [Indexed: 12/25/2022] Open
Abstract
Purposes The main aim of the study was to investigate the dosimetric difference between acuros XB algorithm (AXB), anisotropic analytic algorithm (AAA), and pencil beam convolution (PBC) algorithm in stereotactic body radiation therapy (SBRT) plan for non-small cell lung cancer (NSCLC). Patients and Methods Thirty-eight NSCLC patients were included. GTV, PTV, and organs at risk were delineated by the radiation oncologists. Three optimized SBRT plans for each patients were gained using three algorithms of AXB, AAA, and PBC with the identical plan parameters. Dosimetric endpoints were collected and compared among the three plans, including dosimetric criteria: V100%, V90%, PTV Dmin, Dmax, Dmean, homogeneity index (HI), and Paddick conformity index (CI). Results AXB plan resulted in decreased V100% with a mean difference 6.14% compared with PBC plan (For V100%, AXB vs AAA vs PBC=93.44% vs 95.54% vs 99.58%, P<0.05). Three plans showed no significant difference as to the parameter V90%. AXB plan leaded to reduced Dmin of PTV compared with other two algorithms (For Dmin of PTV, AXB vs AAA vs PBC=4048cGy vs 4365Gy vs 4873Gy, P<0.05). PBC induced the enhanced trend of Dmax of PTV compared with other two algorithms (Dmax among three algorithms, P>0.05); and increased the Dmean of PTV in three algorithms with significant difference (For Dmean of PTV, AXB vs AAA vs PBC=5332cGy vs 5330Gy vs 5785Gy, P<0.05). AXB algorithm achieved a similar plan conformity with other two algorithms (For CI, AXB vs AAA vs PBC=0.80 vs 0.85 vs 0.71, P>0.05). Conclusion For SBRT plan of NSCLC, AAA and PBC algorithms overestimate target coverage, AXB algorithm is recommended for the SBRT plan of NSCLC.
Collapse
Affiliation(s)
- Jun Zhang
- Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Hubei 430072, People's Republic of China
| | - Dazhen Jiang
- Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Hubei 430072, People's Republic of China
| | - Huanfan Su
- Jiangxi Medical College, Department of Medical Imaging, Shangrao, Jiangxi 334000, People's Republic of China
| | - Zhitao Dai
- School of Physics and Technology, Wuhan University , Wuhan 430071, People's Republic of China
| | - Jing Dai
- Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Hubei 430072, People's Republic of China
| | - Hui Liu
- Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Hubei 430072, People's Republic of China
| | - Conghua Xie
- Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Hubei 430072, People's Republic of China
| | - Haijun Yu
- Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Hubei 430072, People's Republic of China
| |
Collapse
|
16
|
Neph R, Ouyang C, Neylon J, Yang Y, Sheng K. Parallel beamlet dose calculation via beamlet contexts in a distributed multi-GPU framework. Med Phys 2019; 46:3719-3733. [PMID: 31183871 DOI: 10.1002/mp.13651] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/03/2019] [Accepted: 06/03/2019] [Indexed: 12/14/2022] Open
Abstract
PURPOSE Dose calculation is one of the most computationally intensive, yet essential tasks in the treatment planning process. With the recent interest in automatic beam orientation and arc trajectory optimization techniques, there is a great need for more efficient model-based dose calculation algorithms that can accommodate hundreds to thousands of beam candidates at once. Foundational work has shown the translation of dose calculation algorithms to graphical processing units (GPUs), lending to remarkable gains in processing efficiency. But these methods provide parallelization of dose for only a single beamlet, serializing the calculation of multiple beamlets and under-utilizing the potential of modern GPUs. In this paper, the authors propose a framework enabling parallel computation of many beamlet doses using a novel beamlet context transformation and further embed this approach in a scalable network of multi-GPU computational nodes. METHODS The proposed context-based transformation separates beamlet-local density and TERMA into distinct beamlet contexts that independently provide sufficient data for beamlet dose calculation. Beamlet contexts are arranged in a composite context array with dosimetric isolation, and the context array is subjected to a GPU collapsed-cone convolution superposition procedure, producing the set of beamlet-specific dose distributions in a single pass. Dose from each context is converted to a sparse representation for efficient storage and retrieval during treatment plan optimization. The context radius is a new parameter permitting flexibility between the speed and fidelity of the dose calculation process. A distributed manager-worker architecture is constructed around the context-based GPU dose calculation approach supporting an arbitrary number of worker nodes and resident GPUs. Phantom experiments were executed to verify the accuracy of the context-based approach compared to Monte Carlo and a reference CPU-CCCS implementation for single beamlets and broad beams composed by addition of beamlets. Dose for representative 4π beam sets was calculated in lung and prostate cases to compare its efficiency with that of an existing beamlet-sequential GPU-CCCS implementation. Code profiling was also performed to evaluate the scalability of the framework across many networked GPUs. RESULTS The dosimetric accuracy of the context-based method displays <1.35% and 2.35% average error from the existing serialized CPU-CCCS algorithm and Monte Carlo simulation for beamlet-specific PDDs in water and slab phantoms, respectively. The context-based method demonstrates substantial speedup of up to two orders of magnitude over the beamlet-sequential GPU-CCCS method in the tested configurations. The context-based framework demonstrates near linear scaling in the number of distributed compute nodes and GPUs employed, indicating that it is flexible enough to meet the performance requirements of most users by simply increasing the hardware utilization. CONCLUSIONS The context-based approach demonstrates a new expectation of performance for beamlet-based dose calculation methods. This approach has been successful in accelerating the dose calculation process for very large-scale treatment planning problems - such as automatic 4π IMRT beam orientation and VMAT arc trajectory selection, with hundreds of thousands of beamlets - in clinically feasible timeframes. The flexibility of this framework makes it as a strong candidate for use in a variety of other very large-scale treatment planning tasks and clinical workflows.
Collapse
Affiliation(s)
- Ryan Neph
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
| | - Cheng Ouyang
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
| | - John Neylon
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
| | - Youming Yang
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
| | - Ke Sheng
- Department of Radiation Oncology, University of California Los Angeles, 200 Medical Plaza, #B265, Los Angeles, California, 90095, USA
| |
Collapse
|
17
|
Evaluating small field dosimetry with the Acuros XB (AXB) and analytical anisotropic algorithm (AAA) dose calculation algorithms in the eclipse treatment planning system. JOURNAL OF RADIOTHERAPY IN PRACTICE 2019. [DOI: 10.1017/s1460396919000104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractBackground:An increasing number of external beam treatment modalities including intensity modulated radiation therapy, volumetric modulated arc therapy (VMAT) and stereotactic radiosurgery uses very small fields for treatment planning and delivery. However, there are major challenges in small photon field dosimetry, due to the partial occlusion of the direct photon beam source’s view from the measurement point, lack of lateral charged particle equilibrium, steep dose-rate gradient and volume averaging effect of the detector response and variation of the energy fluence in the lateral direction of the beam. Therefore, experimental measurements of dosimetric parameters such as percent depth doses (PDDs), beam profiles and relative output factors (ROFs) for small fields continue to be a challenge.Materials and Methods:In this study, we used a homogeneous water phantom and the heterogeneous anthropomorphic stereotactic end-to-end verification (STEEV) head phantom for all dose measurements and calculations. PDDs, lateral dose profiles and ROFs were calculated in the Eclipse Treatment Planning System version 13·6 using the Acuros XB (AXB) and the analytical anisotropic algorithms (AAAs) in a homogenous water phantom. Monte Carlo (MC) simulations and measurements using the Exradin W1 Scintillator were also accomplished for four photon energies: 6 MV, 6FFF, 10 MV and 10FFF. Two VMAT treatment plans were generated for two different targets: one located in the brain and the other in the neck (close to the trachea) in the head phantom (CIRS, Norfolk, VA, USA). A Varian Truebeam linear accelerator (Varian, Palo Alto, CA, USA) was used for all treatment deliveries. Calculated results with AXB and AAA were compared with MC simulations and measurements.Results:The average difference of PDDs between W1 Exradin Scintillator measurements and MC simulations, AAA and AXB algorithm calculations were 1·2, 2·4 and 3·2%, respectively, for all field sizes and energies. AXB and AAA showed differences in ROF of about 0·3 and 2·9%, respectively, compared with W1 Exradin Scintillator measured values. For the target located in the brain in the head phantom, the average dose difference between W1 Exradin Scintillator and the MC simulations, AAA and AXB were 0·2, 3·2 and 2·7%, respectively, for all field sizes. Similarly, for the target located in the neck, the respective dose differences were 3·8, 5·7 and 3·5%.Conclusion:In this study, we compared dosimetric parameters such as PDD, beam profile and ROFs in water phantom and isocenter point dose measurements in an anthropomorphic head phantom representing a patient. We observed that measurements using the W1 Exradin scintillator agreed well with MC simulations and can be used efficiently for dosimetric parameters such as PDDs and dose profiles and patient-specific quality assurance measurements for small fields. In both homogenous and heterogeneous media, the AXB algorithm dose prediction agrees well with MC and measurements and was found to be superior to the AAA algorithm.
Collapse
|
18
|
Bedford JL. Calculation of absorbed dose in radiotherapy by solution of the linear Boltzmann transport equations. Phys Med Biol 2019; 64:02TR01. [PMID: 30524016 DOI: 10.1088/1361-6560/aaf0e2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Over the last decade, dose calculations which solve the linear Boltzmann transport equations have been introduced into clinical practice and are now in widespread use. However, knowledge in the radiotherapy community concerning the details of their function is limited. This review gives a general description of the linear Boltzmann transport equations as applied to calculation of absorbed dose in clinical radiotherapy. The aim is to elucidate the principles of the method, rather than to describe a particular implementation. The literature on the performance of typical algorithms is then reviewed, in many cases with reference to Monte Carlo simulations. The review is completed with an overview of the emerging applications in the important area of MR-guided radiotherapy.
Collapse
Affiliation(s)
- James L Bedford
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5PT, United Kingdom
| |
Collapse
|
19
|
Rijken J, Jordan B, Crowe S, Kairn T, Trapp J. Improving accuracy for stereotactic body radiotherapy treatments of spinal metastases. J Appl Clin Med Phys 2018; 19:453-462. [PMID: 29943895 PMCID: PMC6123175 DOI: 10.1002/acm2.12395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 04/09/2018] [Accepted: 05/31/2018] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Use of SBRT techniques is now a relatively common recourse for spinal metastases due to good local control rates and durable pain control. However, the technique has not yet reached maturity for gantry-based systems, so work is still required in finding planning approaches that produce optimum conformity as well as delivery for the slew of treatment planning systems and treatment machines. METHODS A set of 32 SBRT spine treatment plans based on four vertebral sites, varying in modality and number of control points, were created in Pinnacle. These plans were assessed according to complexity metrics and planning objectives as well as undergoing treatment delivery QA on an Elekta VersaHD through ion chamber measurement, ArcCheck, film-dose map comparison and MLC log-file reconstruction via PerFraction. RESULTS All methods of QA demonstrated statistically significant agreement with each other (r = 0.63, P < 0.001). Plan complexity and delivery accuracy were found to be independent of MUs (r = 0.22, P > 0.05) but improved with the number of control points (r = 0.46, P < 0.03); with use of 90 control points producing the most complex and least accurate plans. The fraction of small apertures used in treatment had no impact on plan quality or accuracy (r = 0.29, P > 0.05) but rather more complexly modulated plans showed poorer results due to MLC leaf position inaccuracies. Plans utilizing 180 and 240 control points produced optimal plan coverage with similar complexity metrics to each other. However, plans with 240 control points demonstrated slightly better delivery accuracy, with fewer MLC leaf position discrepancies. CONCLUSION In contrast to other studies, MU had no effect on delivery accuracy, with the most impactful parameter at the disposal of the planner being the number of control points utilized.
Collapse
Affiliation(s)
- James Rijken
- Genesis CareFlinders Private HospitalBedford ParkSAAustralia
- Queensland University of TechnologyBrisbaneQLDAustralia
| | - Barry Jordan
- Genesis CareFlinders Private HospitalBedford ParkSAAustralia
| | - Scott Crowe
- Queensland University of TechnologyBrisbaneQLDAustralia
- Royal Brisbane and Women's HospitalBrisbaneQLDAustralia
| | - Tanya Kairn
- Queensland University of TechnologyBrisbaneQLDAustralia
- Royal Brisbane and Women's HospitalBrisbaneQLDAustralia
| | - Jamie Trapp
- Royal Brisbane and Women's HospitalBrisbaneQLDAustralia
| |
Collapse
|
20
|
Fogliata A, Lobefalo F, Reggiori G, Stravato A, Tomatis S, Scorsetti M, Cozzi L. Evaluation of the dose calculation accuracy for small fields defined by jaw or MLC for AAA and Acuros XB algorithms. Med Phys 2016; 43:5685. [DOI: 10.1118/1.4963219] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
21
|
Mampuya WA, Nakamura M, Hirose Y, Kitsuda K, Ishigaki T, Mizowaki T, Hiraoka M. Difference in dose-volumetric data between the analytical anisotropic algorithm, the dose-to-medium, and the dose-to-water reporting modes of the Acuros XB for lung stereotactic body radiation therapy. J Appl Clin Med Phys 2016; 17:341-347. [PMID: 27685138 PMCID: PMC5874099 DOI: 10.1120/jacmp.v17i5.6338] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 06/08/2016] [Accepted: 06/08/2016] [Indexed: 11/24/2022] Open
Abstract
The purpose of this study was to evaluate the difference in dose‐volumetric data between the analytical anisotropic algorithms (AAA) and the two dose reporting modes of the Acuros XB, namely, the dose to water (AXB−Dw) and dose to medium (AXB−Dm) in lung stereotactic body radiotherapy (SBRT). Thirty‐eight plans were generated using the AXB−Dm in Eclipse Treatment Planning System (TPS) and then recalculated with the AXB−Dw and AAA, using identical beam setup. A dose of 50 Gy in 4 fractions was prescribed to the isocenter and the planning target volume (PTV) D95%. The isocenter was always inside the PTV. The following dose‐volumetric parameters were evaluated; D2%, D50%, D95%, and D98% for the internal target volume (ITV) and the PTV. Two‐tailed paired Student's t‐tests determined the statistical significance. Although for most of the parameters evaluated, the mean differences observed between the AAA, AXB−Dmand AXB−Dw were statistically significant (p<0.05), absolute differences were rather small, in general less than 5% points. The maximum mean difference was observed in the ITV D50% between the AXB−Dm and the AAA and was 1.7% points under the isocenter prescription and 3.3% points under the D95 prescription. AXB−Dm produced higher values than AXB−Dw with differences ranging from 0.4 to 1.1% points under isocenter prescription and 0.0 to 0.7% points under the PTV D95% prescription. The differences observed under the PTV D95% prescription were larger compared to those observed for the isocenter prescription between AXB−Dm and AAA, AXB−Dm and AXB−Dw, and AXB−Dw and AAA. Although statistically significant, the mean differences between the three algorithms are within 3.3% points. PACS number(s): 87.55.x, 87.55.D‐, 87.55.dk
Collapse
|