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Zhang R, Bai J, Wang R, Yan J, Chang L, Bai H. Quantified difference of the collapsed cone convolution (CCC) and Monte Carlo (MC) algorithms based on DVH and gamma analysis for cervical cancer radiation therapy. Appl Radiat Isot 2024; 210:111340. [PMID: 38749237 DOI: 10.1016/j.apradiso.2024.111340] [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: 10/01/2023] [Revised: 03/27/2024] [Accepted: 05/02/2024] [Indexed: 06/13/2024]
Abstract
OBJECTIVE To quantify the difference between the (collapsed cone convolution) CCC algorithm and the (Monte Carlo) MC algorithm and remind that the planners should pay attention to some possible uncertainties of the two algorithms when employing the two algorithms. METHODS Thirty patients' cervical cancer VMAT plans were designed with a Pinnacle TPS (Philips) and divided equally into two groups: the simple group (SG, target volume was only the PTV) and the complex group (CG, target volume included the PTV and PGTV). The plans from the Pinnacle TPS were transferred to the Monaco TPS (Elekta). The plans' parameters all remained unchanged, and the dose was recalculated. Gamma passing rates (GPRs) obtained from dose distribution from Pinnacle TPS compared with that from Monaco TPS with SNC software based on three triaxial planes (transverse, sagittal and coronal). GPRs and DVH were used to quantify the difference between the CCC algorithm in pinnacle TPS and the MC algorithm in Monaco TPS. RESULTS Among the statistical dose indexes in DVHs from the Pinnacle and Monaco TPSs, there were 7(7/15) dose indexes difference with statistically significant differences in the SG, and 10(10/18) dose indexes difference with statistically significant differences in the CG. With 3%/3 mm criterion, the most (5/6) GPRs were greater than 95% from the SG and CG. But with 2%/2 mm criterion, the most (5/6) GPRs were less than 90% from the two groups. In addition, we found that GPRs were also related to the selected triaxial planes and the complexity of the plan (GPRs varied with the SG and CG). CONCLUSIONS Obvious difference between the CCC and MC algorithms from Pinnacle and Monaco TPS. DVH maybe better than 2D gamma analysis on quantifying difference of the CCC and MC algorithms. Some attention should be paid to the uncertainty of the TPS algorithm, especially when the indicator on the DVH is at the critical point of the threshold value, because the algorithm used may overestimate or underestimate the DVH indicator.
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Affiliation(s)
- Rui Zhang
- Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, Yunnan, China; Department of Radiation Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jie Bai
- Department of Radiation Oncology, Daqin Cancer Hospital, Guiyang, Guizhou, China
| | - Ru Wang
- Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, Yunnan, China
| | - Jiawen Yan
- Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, Yunnan, China
| | - Li Chang
- Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, Yunnan, China
| | - Han Bai
- Department of Radiation Oncology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, Yunnan, China; Department of Physics and Astronomy, Yunnan University, Kunming, Yunnan, China.
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Da Silva Mendes V, Nierer L, Li M, Corradini S, Reiner M, Kamp F, Niyazi M, Kurz C, Landry G, Belka C. Dosimetric comparison of MR-linac-based IMRT and conventional VMAT treatment plans for prostate cancer. Radiat Oncol 2021; 16:133. [PMID: 34289868 PMCID: PMC8296626 DOI: 10.1186/s13014-021-01858-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/12/2021] [Indexed: 02/07/2023] Open
Abstract
Background The aim of this study was to evaluate and compare the performance of intensity modulated radiation therapy (IMRT) plans, planned for low-field strength magnetic resonance (MR) guided linear accelerator (linac) delivery (labelled IMRT MRL plans), and clinical conventional volumetric modulated arc therapy (VMAT) plans, for the treatment of prostate cancer (PCa). Both plans used the original planning target volume (PTV) margins. Additionally, the potential dosimetric benefits of MR-guidance were estimated, by creating IMRT MRL plans using smaller PTV margins. Materials and methods 20 PCa patients previously treated with conventional VMAT were considered. For each patient, two different IMRT MRL plans using the low-field MR-linac treatment planning system were created: one with original (orig.) PTV margins and the other with reduced (red.) PTV margins. Dose indices related to target coverage, as well as dose-volume histogram (DVH) parameters for the target and organs at risk (OAR) were compared. Additionally, the estimated treatment delivery times and the number of monitor units (MU) of each plan were evaluated. Results The dose distribution in the high dose region and the target volume DVH parameters (D98%, D50%, D2% and V95%) were similar for all three types of treatment plans, with deviations below 1% in most cases. Both IMRT MRL plans (orig. and red. PTV margins) showed similar homogeneity indices (HI), however worse values for the conformity index (CI) were also found when compared to VMAT. The IMRT MRL plans showed similar OAR sparing when the orig. PTV margins were used but a significantly better sparing was feasible when red. PTV margins were applied. Higher number of MU and longer predicted treatment delivery times were seen for both IMRT MRL plans. Conclusions A comparable plan quality between VMAT and IMRT MRL plans was achieved, when applying the same PTV margin. However, online MR-guided adaptive radiotherapy allows for a reduction of PTV margins. With a red. PTV margin, better sparing of the surrounding tissues can be achieved, while maintaining adequate target coverage. Nonetheless, longer treatment delivery times, characteristic for the IMRT technique, have to be expected.
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Affiliation(s)
- Vanessa Da Silva Mendes
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany.
| | - Lukas Nierer
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Minglun Li
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Stefanie Corradini
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Michael Reiner
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Florian Kamp
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany.,Department of Radiation Oncology, Cologne University Hospital, Cologne, Germany
| | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Christopher Kurz
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Guillaume Landry
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistraße 15, 81377, Munich, Germany.,German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany
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Sasaki M, Nakaguchi Y, Kamomae T, Kajino A, Ikushima H. Impact of treatment planning quality assurance software on volumetric-modulated arc therapy plans for prostate cancer patients. Med Dosim 2021; 46:e1-e6. [PMID: 33972163 DOI: 10.1016/j.meddos.2021.03.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Software that evaluates the quality of treatment plans (PlanIQTM) has become commercially available in recent years. It includes a feasibility assessment tool that provides the ideal dose volume histogram (DVH) for each organ at risk, based on the ideal dose falloff from the prescribed dose at the target boundary. It is important to investigate whether the PlanIQTM assessment tool (Feasibility DVHTM) can assist treatment planners who have limited to no experience in treatment planning. Therefore, the present study aimed to evaluate this tool's usefulness for improving the quality of treatment plans. MATERIALS & METHODS This study included 5 patients with prostate cancer. The treatment planners were 2 graduate students, 2 undergraduate students, and one clinical planner. All students were radiological technology and medical physics students with no clinical experience. Two different volumetric-modulated arc therapy (VMAT) plans were developed before and after Feasibility DVHTM. The quality of each treatment plan was evaluated based on a scoring system implemented in PlanIQTM. RESULTS Of 5 patients included, 4 received improved treatment plans when Feasibility DVHTM was used. Moreover, 4 of 5 treatment planners showed improvement in treatment planning using Feasibility DVHTM. CONCLUSIONS The findings suggest that using the Feasibility DVHTM tool may improve treatment plans for different planners and patients. However, planners at any level of experience should be trained to check the dose distribution in addition to checking the DVH, which depends on the adequacy of the contours.
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Affiliation(s)
- Motoharu Sasaki
- Department of Therapeutic Radiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Tokushima 770-8503, Japan.
| | | | - Takeshi Kamomae
- Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Akimi Kajino
- School of Health Sciences, Tokushima University, Tokushima 770-8503, Japan
| | - Hitoshi Ikushima
- Department of Therapeutic Radiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Tokushima 770-8503, Japan
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Sasaki M, Nakaguuchi Y, Kamomae T, Tsuzuki A, Kobuchi S, Kuwahara K, Ueda S, Endo Y, Ikushima H. Analysis of prostate intensity- and volumetric-modulated arc radiation therapy planning quality with PlanIQ TM. J Appl Clin Med Phys 2021; 22:132-142. [PMID: 33768648 PMCID: PMC8035557 DOI: 10.1002/acm2.13233] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 02/21/2021] [Accepted: 03/02/2021] [Indexed: 11/21/2022] Open
Abstract
Purpose The purpose of this study was to assess the quality of treatment planning using the PlanIQTM software and to investigate whether it is possible to improve the quality of treatment planning using the “Feasibility dose‐volume histogram (DVH)TM” implemented in the PlanIQTM software. Methods Using the PlanIQTM software, we retrospectively analyzed the learning curve regarding the quality of the treatment plans for 148 patients of prostate intensity‐modulated radiation therapy and volumetric‐modulated radiation therapy performed at our institution over the past eight years. We also sought to examine the possibility of improving treatment planning quality by re‐planning in 47 patients where the quality of the target dose and the dose limits for organs at risk (OARs) were inadequate. The re‐planning treatment plans referred to the Feasibility DVHTM implemented in the PlanIQTM software and modified the treatment planning system based on the target dose and OAR constraints. Results Analysis of the learning curve of the treatment plans quality using PlanIQTM software retrospectively showed a trend of improvement in the treatment plan quality from year to year. The improvement in the treatment plans quality was more influenced by dose reduction in the OARs than by target coverage. In all cases where re‐planning was performed, the improvement in the treatment plan's quality resulted in a better treatment plan than the one adopted for delivery to patients in the clinical plan. Conclusions The PlanIQTM provided insights into the quality of the treatment plans at our institution and identified problems and areas for improvement in the treatment plans, allowing for the development of appropriate treatment plans for specific patients.
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Affiliation(s)
- Motoharu Sasaki
- Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | | | - Takeshi Kamomae
- Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Akira Tsuzuki
- Department of Radiological Technology, Kochi University Hospital, Kochi, Japan
| | - Satoshi Kobuchi
- Graduate School of Health Sciences, Tokushima University, Tokushima, Japan
| | - Kenmei Kuwahara
- Graduate School of Health Sciences, Tokushima University, Tokushima, Japan
| | - Shoji Ueda
- School of Health Sciences, Tokushima University, Tokushima, Japan
| | - Yuto Endo
- School of Health Sciences, Tokushima University, Tokushima, Japan
| | - Hitoshi Ikushima
- Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
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Miyazaki M, Ohira S, Ueda Y, Isono M, Fujiwara M, Tanooka M, Okada W, Nakahara R, Sueoka M, Suzuki H, Teshima T, Yamakado K. Oesophageal Cancer: Conformal Radiotherapy vs. Hybrid-VMAT Technique With Two Different Treatment Planning Systems. IN VIVO (ATHENS, GREECE) 2020; 34:331-337. [PMID: 31882496 DOI: 10.21873/invivo.117778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 10/30/2019] [Accepted: 11/05/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND/AIM Traditionally, the radiotherapy of oesophageal cancer has been conformal radiotherapy (CRT). We sought to compare dosimetric parameters of conformal radiotherapy (CRT) with those of two treatment planning systems for hybrid-volumetric modulated arc therapy (h-VMAT) for the treatment of oesophageal cancer. PATIENTS AND METHODS In 11 patients, we compared: i) planning target volume coverage, ii) dose to organs at risk, and iii) the dose rate (DR) of the three techniques. We evaluated two treatment planning systems: i) Eclipse and ii) RayStation. RESULTS The Conformity Index of the CRT plan was significantly higher for the h-VMAT plans, compared to all other parameters. Normal lung tissue volumes receiving >5, 13, or 20 Gy were lower with the RayStation plan compared to Eclipse. The volume of cardiac tissue receiving >40 Gy was highest with the CRT plan. The minimum DR in VMAT was lowest for the RayStation plan (49.5 MU/min). CONCLUSION The h-VMAT plan using RayStation is the appropriate choice for reducing lung dose.
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Affiliation(s)
- Masayoshi Miyazaki
- Department of Radiology, Hyogo College of Medicine, Hyogo, Japan .,Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan
| | - Shingo Ohira
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan.,Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yoshihiro Ueda
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan.,Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Masaru Isono
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan
| | | | - Masao Tanooka
- Department of Radiology, Hyogo College of Medicine, Hyogo, Japan
| | - Wataru Okada
- Department of Radiology, Hyogo College of Medicine, Hyogo, Japan
| | - Ryuta Nakahara
- Department of Radiology, Hyogo College of Medicine, Hyogo, Japan
| | - Masaki Sueoka
- Department of Radiology, Hyogo College of Medicine, Hyogo, Japan
| | - Hitomi Suzuki
- Department of Radiology, Hyogo College of Medicine, Hyogo, Japan
| | - Teruki Teshima
- Department of Radiation Oncology, Osaka International Cancer Institute, Osaka, Japan
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Melles-Bencsik B, Pócza T, Major T, Ágoston P, Jorgo K, Polgár C, Pesznyák C. Normal tissue sparing using different techniques for prostate irradiation. Rep Pract Oncol Radiother 2020; 25:85-90. [DOI: 10.1016/j.rpor.2019.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 09/10/2019] [Accepted: 11/29/2019] [Indexed: 11/16/2022] Open
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Grigorov G, Chow JC, Bauman G, Darko J, Kiciak A, Osei E. A Novel 2D Probability Density Function Integrating the Rectal Motion and Wall Thickness in Prostate IMRT. J Med Imaging Radiat Sci 2019; 50:488-498. [DOI: 10.1016/j.jmir.2019.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 09/03/2019] [Accepted: 09/05/2019] [Indexed: 11/26/2022]
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Lee YK, Munawar I, Mashouf S, Sahgal A, Ruschin M. Dosimetric comparison of two treatment planning systems for spine SBRT. Med Dosim 2019; 45:77-84. [PMID: 31376988 DOI: 10.1016/j.meddos.2019.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 06/13/2019] [Accepted: 07/02/2019] [Indexed: 10/26/2022]
Abstract
Two commonly used treatment planning systems (TPS) are compared for the planning of spine stereotactic body radiotherapy (SBRT). The main purpose is to highlight relative advantages and disadvantages of each system and propose a methodologic approach for comparisons. Twenty clinical plans were inversely planned with step-and-shoot intensity-modulated radiotherapy (IMRT) each using 9 to 11 beams, referred to as IMRT_P. The prescription dose was 24 Gy in 2 fractions, and the plans were generated following our institutional protocol using the Pinnacle3 v9.2. Each case was replanned using a 2-arc volumetric modulated arc therapy (VMAT) approach, referred as VMAT_P. CT and structure sets were DICOM exported to Monaco v5.10 and planned in 2 different ways: IMRT (IMRT_M) and VMAT (VMAT_M) using the same prescription dose. Dose volume histograms (DVH) and other dose statistics of planning target volumes (PTV) and organ-at-risk (OAR) were analyzed and compared between plans. The gradient index (GI = ratio of 50% isodose volume to prescribed isodose volume) was used to measure dose fall-off outside of the PTV. Another metric - Gradient Index Inner (GIinner = the rate (in Gy/mm) - at which the dose changes from the level of the spinal cord/thecal sac toward the prescription dose) was developed and compared. All plans were considered clinically acceptable by institutional guidelines and achieved all of the OAR dose constraints. VMAT_M and IMRT_M showed comparable dose statistics for the PTV when compared to VMAT_P and IMRT_P, respectively. For IMRT plans, the median GIinner was 1.88 Gy/mm vs 1.52 Gy/mm for IMRT_M and IMRT_P respectively (p< 0.001). All other IMRT metrics were statistically similar except for the PTV maximum dose (Dmax), which was higher for IMRT_M than IMRT_P (median 30.7 Gy vs 29.0 Gy, p< 0.001). For VMAT plans, only PTV Dmin showed a statistical different between VMAT_M and VMAT_P of median 12.7 Gy vs 9.7 Gy (p< 0.001). In terms of beam sequencing parameters, the number of monitor units was statistically higher for VMAT_P compared to VMAT_M (median = 6764 vs 5376) whereas the number of segments for IMRT_M was statistically greater than IMRT_P (median = 155 vs 73). We were able to generate clinically acceptable plans for different types of spine SBRT using 2 different TPS. We used an evaluation strategy involving coverage, conformity, and dose gradient that can compared between TPS.
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Affiliation(s)
- Young Kyung Lee
- Department of Medical Physics, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON M4N 3M5, Canada.
| | - Iram Munawar
- Department of Medical Physics, Trillium Health Partners, the Credit Valley Hospital, Mississauga, Canada
| | - Shahram Mashouf
- Department of Medical Physics, Marshfield Clinic Health System, Marshfield, WI 54449, USA
| | - Arjun Sahgal
- Department of Radiation Oncology, University of Toronto, Toronto, ON M4N 3M5, Canada; Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Mark Ruschin
- Department of Medical Physics, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON M4N 3M5, Canada
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Radhakrishnan S, Chandrasekaran A, Sarma Y, Balakrishnan S, Nandigam J. Dosimetric Comparison between Single and Dual Arc-Volumetric Modulated Arc Radiotherapy and Intensity Modulated Radiotherapy for Nasopharyngeal Carcinoma Using a Simultaneous Integrated Boost Technique. Asian Pac J Cancer Prev 2017; 18:1395-1402. [PMID: 28612593 PMCID: PMC5555553 DOI: 10.22034/apjcp.2017.18.5.1395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Backround: Plan quality and performance of dual arc (DA) volumetric modulated arc therapy (VMAT), single arc (SA) VMAT and nine field (9F) intensity modulated radiotherapy were compared using a simultaneous integrated boost (SIB) technique. Methods: Twelve patients treated in Elekta Synergy Platform (mlci2) by 9F-IMRT were replanned with SA/DA-VMAT using a CMS Monaco Treatment Planning System (TPS) with Monte Carlo simulation. Target delineation was conducted as per Radiation Therapy Oncology Protocols (RTOG0225 and 0615). A 70Gy dose prescribed to PTV70 and 61Gy to PTV61 in 33 fractions was applied for the SIB technique. The conformity index (CI) and homogeneity index (HI) for targets and the mean dose and maximum dose for OAR’s, treatment delivery time (min), monitor units (MUs) per fraction, normal tissue integral dose and patient specific quality assurance were analysed. Results: Acceptable target coverage was achieved for PTV70 and PTV61 with all the planning techniques. No significant differences were observed except for D98 (PTV61), CI(PTV70) and HI(PTV61). Maximum dose (Dmax) to the spinal cord was lower in DA-VMAT than 9F-IMRT (p=0.002) and SA-VMAT (p=0.001). D50 (%) of parotid glands was better controlled by 9F-IMRT (p=0.001) and DA-VMAT (p=0.001) than SA-VMAT. A lower mean dose to the larynx was achieved with 9F-IMRT (P=0.001) and DA-VMAT (p=0.001) than with SA-VMAT. DA-VMAT achieved higher CI of PTV70 (P= 0.005) than SA-VMAT. For PTV61, DA-VMAT (P=0.001) and 9F-IMRT (P=0.001) achieved better HI than SA-VMAT. The average treatment delivery times were 7.67mins, 3.35 mins, 4.65 mins for 9F-IMRT, SA-VMAT and DA-VMAT, respectively. No significant difference were observed in MU/fr (p=0.9) and NTID (P=0.90) and the patient quality assurance pass rates were >95% (gamma analysis I3mm, 3%). Conclusion: DA-VMAT showed better conformity over target dose and spared the OARs better or equal to IMRT. SA-VMAT could not spare the OARs well. DA-VMAT offered shorter delivery time than IMRT without compromising the plan quality.
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Affiliation(s)
- Sivakumar Radhakrishnan
- Department Of Physics, VIT University, Vellore, India.,Department Of Radiotherapy, Omega Hospitals, Hyderabad, India.
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Assessment of monitor unit limiting strategy using volumetric modulated arc therapy for cancer of hypopharynx. Phys Med 2017; 35:73-80. [PMID: 28228330 DOI: 10.1016/j.ejmp.2017.01.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 01/05/2017] [Accepted: 01/21/2017] [Indexed: 11/21/2022] Open
Abstract
PURPOSE To quantify relative merit of MU deprived plans against freely optimized plans in terms of plan quality and report changes induced by progressive resolution optimizer algorithm (PRO3) to the dynamic parameters of RapidArc. MATERIALS AND METHODS Ten cases of carcinoma hypopharynx were retrospectively planned in three phases without using MU tool. Replicas of these baseline plans were reoptimized using "Intermediate dose" feature and "MU tool" to reduce MUs by 20%, 35%, and 50%. Overall quality indices for target and OAR, integral dose, dose-volume spread were assessed. All plans were appraised for changes induced in RapidArc dynamic parameters and pre-treatment quality assurance (QA). RESULTS With increasing MU reduction strength (MURS), MU/Gy values reduced, for all phases with an overall range of 8.6-34.7%; mean dose rate decreased among plans of each phase, phase3 plans recorded greater reductions. MURS20% showed good trade-off between MUs and plan quality. Dose-volume spread below 5Gy was higher for baseline plans while lower between 20 and 35Gy. Integral dose was lower for MURS0%, not exceeding 1.0%, compared against restrained plans. Mean leaf aperture and control point areas increased systematically, correlated negatively with increasing MURS. Absolute delta dose rate variations were least for MURS0%. MU deprived plans exhibited GAI (>93%), better than MURS0% plans. CONCLUSION Baseline plans are superior to MU restrained plans. However, MURS20% offers equivalent and acceptable plan quality with mileage of MUs, improved GAI for complex cases. MU tool may be adopted to tailor treatment plans using PRO3.
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Improving plan quality for prostate volumetric-modulated arc therapy. Med Dosim 2017; 42:348-356. [DOI: 10.1016/j.meddos.2017.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/16/2017] [Accepted: 07/03/2017] [Indexed: 11/22/2022]
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Lafond C, Chiavassa S, Bertaut C, Boussion N, Chapel N, Chapron L, Coste F, Crespin S, Dy G, Faye PA, Leleu C, Bouvier J, Madec L, Mesgouez J, Palisson J, Vela A, Delpon G. DEMAT: A multi-institutional dosimetry audit of rotational and static intensity-modulated radiotherapy. Phys Med 2016; 32:664-70. [DOI: 10.1016/j.ejmp.2016.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/03/2016] [Accepted: 04/18/2016] [Indexed: 10/21/2022] Open
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Nithiyanantham K, Mani GK, Subramani V, Mueller L, Palaniappan KK, Kataria T. Analysis of direct clinical consequences of MLC positional errors in volumetric-modulated arc therapy using 3D dosimetry system. J Appl Clin Med Phys 2015; 16:296–305. [PMID: 26699311 PMCID: PMC5690184 DOI: 10.1120/jacmp.v16i5.5515] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 05/06/2015] [Accepted: 04/28/2015] [Indexed: 01/04/2023] Open
Abstract
In advanced, intensity-modulated external radiotherapy facility, the multileaf collimator has a decisive role in the beam modulation by creating multiple segments or dynamically varying field shapes to deliver a uniform dose distribution to the target with maximum sparing of normal tissues. The position of each MLC leaf has become more critical for intensity-modulated delivery (step-and-shoot IMRT, dynamic IMRT, and VMAT) compared to 3D CRT, where it defines only field boundaries. We analyzed the impact of the MLC positional errors on the dose distribution for volumetric-modulated arc therapy, using a 3D dosimetry system. A total of 15 VMAT cases, five each for brain, head and neck, and prostate cases, were retrospectively selected for the study. All the plans were generated in Monaco 3.0.0v TPS (Elekta Corporation, Atlanta, GA) and delivered using Elekta Synergy linear accelerator. Systematic errors of +1, +0.5, +0.3, 0, -1, -0.5, -0.3 mm were introduced in the MLC bank of the linear accelerator and the impact on the dose distribution of VMAT delivery was measured using the COMPASS 3D dosim-etry system. All the plans were created using single modulated arcs and the dose calculation was performed using a Monte Carlo algorithm in a grid size of 3 mm. The clinical endpoints D95%, D50%, D2%, and Dmax,D20%, D50% were taken for the evaluation of the target and critical organs doses, respectively. A significant dosimetric effect was found for many cases even with 0.5 mm of MLC positional errors. The average change of dose D 95% to PTV for ± 1 mm, ± 0.5 mm, and ±0.3mm was 5.15%, 2.58%, and 0.96% for brain cases; 7.19%, 3.67%, and 1.56% for head and neck cases; and 8.39%, 4.5%, and 1.86% for prostate cases, respectively. The average deviation of dose Dmax was 5.4%, 2.8%, and 0.83% for brainstem in brain cases; 8.2%, 4.4%, and 1.9% for spinal cord in H&N; and 10.8%, 6.2%, and 2.1% for rectum in prostate cases, respectively. The average changes in dose followed a linear relationship with the amount of MLC positional error, as can be expected. MLC positional errors beyond ± 0.3 mm showed a significant influence on the intensity-modulated dose distributions. It is, therefore, recommended to have a cautious MLC calibration procedure to sufficiently meet the accuracy in dose delivery.
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Gimeno J, Pujades M, García T, Carmona V, Lliso F, Palomo R, Candela-Juan C, Richart J, Perez-Calatayud J. Commissioning and initial experience with a commercial software for in vivo volumetric dosimetry. Phys Med 2014; 30:954-9. [DOI: 10.1016/j.ejmp.2014.06.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 05/12/2014] [Accepted: 06/10/2014] [Indexed: 11/29/2022] Open
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Mancosu P, Reggiori G, Alongi F, Cozzi L, Fogliata A, Lobefalo F, Navarria P, Stravato A, Tomatis S, Scorsetti M. Total monitor units influence on plan quality parameters in volumetric modulated arc therapy for breast case. Phys Med 2014; 30:296-300. [DOI: 10.1016/j.ejmp.2013.08.142] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 08/26/2013] [Accepted: 08/29/2013] [Indexed: 10/26/2022] Open
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Andreou M, Karaiskos P, Kordolaimi S, Koutsouveli E, Sandilos P, Dimitriou P, Dardoufas C, Georgiou E. Anatomy- vs. fluence-based planning for prostate cancer treatments using VMAT. Phys Med 2014; 30:202-8. [DOI: 10.1016/j.ejmp.2013.05.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 05/09/2013] [Accepted: 05/22/2013] [Indexed: 12/12/2022] Open
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Comparison of IMRT and VMAT plans with different energy levels using Monte-Carlo algorithm for prostate cancer. Jpn J Radiol 2014; 32:224-32. [PMID: 24510241 DOI: 10.1007/s11604-014-0291-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 01/17/2014] [Indexed: 10/25/2022]
Abstract
PURPOSE To make dosimetric comparisons of volumetric-modulated arc therapy (VMAT) and 7-field intensity-modulated radiotherapy (IMRT) with dynamic MLCs using the Monaco treatment planning system with Monte Carlo algorithm. MATERIALS AND METHODS Single-arc VMAT and 7-field IMRT treatment plans were compared for 12 intermediate risk prostate cancer patients treated with prostate and seminal vesicle radiotherapy. For all patients, the prescribed dose was 78 Gy delivered in 39 fractions. The dosimetric data of IMRT and VMAT plans with 6, 10 and 15 MV energies were compared. The comparison was made for target volume, organs at risk (OAR) doses, and for monitor units (MU). RESULTS The normal tissue surrounding the target were lower in VMAT plans compared to IMRT plans. VMAT plans achieved lower doses to all OARs for nearly all dosimetric endpoints. VMAT plans achieved 9.4, 9.0 and 7.0 % relative decrease in MUs required for RT delivery, for 6, 10 and 15 MV energy levels, respectively. The target volume and OAR dosimetric values did not differ significantly between 6, 10 and 15 MV photon energies. CONCLUSION VMAT plans were found to be dosimetrically equivalent to IMRT plans for prostate cancer patients, with better rectum and bladder sparing and fewer MUs required.
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Onal C, Sonmez S, Erbay G, Guler OC, Arslan G. Simultaneous integrated boost to intraprostatic lesions using different energy levels of intensity-modulated radiotherapy and volumetric-arc therapy. Br J Radiol 2013; 87:20130617. [PMID: 24319009 DOI: 10.1259/bjr.20130617] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVE This study compared the dosimetry of volumetric-arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) with a dynamic multileaf collimator using the Monte Carlo algorithm in the treatment of prostate cancer with and without simultaneous integrated boost (SIB) at different energy levels. METHODS The data of 15 biopsy-proven prostate cancer patients were evaluated. The prescribed dose was 78 Gy to the planning target volume (PTV78) including the prostate and seminal vesicles and 86 Gy (PTV86) in 39 fractions to the intraprostatic lesion, which was delineated by MRI or MR-spectroscopy. RESULTS PTV dose homogeneity was better for IMRT than VMAT at all energy levels for both PTV78 and PTV86. Lower rectum doses (V30-V50) were significantly higher with SIB compared with PTV78 plans in both IMRT and VMAT plans at all energy levels. The bladder doses at high dose level (V60-V80) were significantly higher in IMRT plans with SIB at all energy levels compared with PTV78 plans, but no significant difference was observed in VMAT plans. VMAT plans resulted in a significant decrease in the mean monitor units (MUs) for 6, 10, and 15 MV energy levels both in plans with and those without SIB. CONCLUSION Dose escalation to intraprostatic lesions with 86 Gy is safe without causing serious increase in organs at risk (OARs) doses. VMAT is advantageous in sparing OARs and requiring less MU than IMRT. ADVANCES IN KNOWLEDGE VMAT with SIB to intraprostatic lesion is a feasible method in treating prostate cancer. Additionally, no dosimetric advantage of higher energy is observed.
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Affiliation(s)
- C Onal
- Department of Radiation Oncology, Baskent University Faculty of Medicine, Adana, Turkey
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