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Moradi S, Hashemi B, Bakhshandeh M, Banaei A, Mofid B. Introducing new plan evaluation indices for prostate dose painting IMRT plans based on apparent diffusion coefficient images. Radiat Oncol 2022; 17:193. [PMID: 36419067 PMCID: PMC9685857 DOI: 10.1186/s13014-022-02163-7] [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: 08/01/2022] [Accepted: 11/17/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Dose painting planning would be more complicated due to different levels of prescribed doses and more complex evaluation with conventional plan quality indices considering uniform dose prescription. Therefore, we tried to introduce new indices for evaluating the dose distribution conformity and homogeneity of treatment volumes based on the tumoral cell density and relative volumes of each lesion in prostate IMRT. METHODS CT and MRI scans of 20 male patients having local prostate cancer were used for IMRT DP planning. Apparent diffusion coefficient (ADC) images were imported to a MATLAB program to identify lesion regions based on ADC values automatically. Regions with ADC values lower than 750 mm2/s and regions with ADC values higher than 750 and less than 1500 mm2/s were considered CTV70Gy (clinical tumor volume with 70 Gy prescribed dose), and CTV60Gy, respectively. Other regions of the prostate were considered as CTV53Gy. New plan evaluation indices based on evaluating the homogeneity (IOE(H)), and conformity (IOE(C)) were introduced, considering the relative volume of each lesion and cellular density obtained from ADC images. These indices were compared with conventional homogeneity and conformity indices and IOEs without considering cellular density. Furthermore, tumor control probability (TCP) was calculated for each patient, and the relationship of the assessed indices were evaluated with TCP values. RESULTS IOE (H) and IOE (C) with considering cellular density had significantly lower values compared to conventional indices and IOEs without considering cellular density. (P < 0.05). TCP values had a stronger relationship with IOE(H) considering cell density (R2 = -0.415), and IOE(C) without considering cell density (R2 = 0.624). CONCLUSION IOE plan evaluation indices proposed in this study can be used for evaluating prostate IMRT dose painting plans. We suggested to consider cell densities in the IOE(H) calculation formula and it's appropriate to calculate IOE(C) without considering cell density values.
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Affiliation(s)
- Saman Moradi
- grid.412266.50000 0001 1781 3962Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, 1411713116 Iran
| | - Bijan Hashemi
- grid.412266.50000 0001 1781 3962Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, 1411713116 Iran
| | - Mohsen Bakhshandeh
- grid.411600.2Department of Radiology Technology, Faculty of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, 1985717443 Iran
| | - Amin Banaei
- grid.412266.50000 0001 1781 3962Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, 1411713116 Iran
| | - Bahram Mofid
- grid.411600.2Department of Radiation Oncology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, 1985717443 Iran
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Boudet J, Aubignac L, Beneux A, Mazoyer F, Bessieres I. Evaluation of QA software system analysis for the static picket fence test. J Appl Clin Med Phys 2022; 23:e13618. [PMID: 35570379 PMCID: PMC9278673 DOI: 10.1002/acm2.13618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 02/01/2022] [Accepted: 04/01/2022] [Indexed: 11/16/2022] Open
Abstract
Intensity modulation treatments are widely used in radiotherapy because of many known advantages. In this context, the picket fence test (PF) is a relevant test to check the Multileaf Collimator (MLC) performances. So this work compares and evaluates three analysis platforms for the PF used routinely by three different institutions. This study covers two linear accelerators (Linac) with two MLC types, a Millenium 120 MLC and Millenium 120 High Definition MLC respectively on a Varian Truebeam and Truebeam STx. Both linacs include an As 1200 portal imager (EPID). From a reference PF plan, MLC errors have been introduced to modify the slits in position or width (shifts from 0.1 to 0.5 mm on one or both banks). Then errors have been defined on the EPID to investigate detection system deviations (signal sensitivity and position variations). Finally, 110 DICOM‐RT images have been generated and analyzed by each software system. All software systems have shown good performances to quantify the position errors, even though the leaf pair identifications can be wrong in some cases regarding the analysis method considered. The slit width measurement (not calculated by all software systems) has shown good sensitivity, but some quantification difficulties have been highlighted regardless of the analysis method used. Linked to the expected accuracy of the PF test, the imager variations have demonstrated considerable influence in the results. Differences in the results and the analysis methods have been pointed out for each software system. The results can be helpful to optimize the settings of each analysis software system depending on expectations and treatment modalities of each institution.
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Affiliation(s)
- Julien Boudet
- Department of Physics Centre Georges François Leclerc Dijon France
| | - Léone Aubignac
- Department of Physics Centre Georges François Leclerc Dijon France
| | - Amandine Beneux
- Department of Physics Hospices Civils de Lyon Pierre Bénite France
| | - Frédéric Mazoyer
- Department of Radiotherapy Centre Hospitalier Annecy Genevois Epagny Metz‐Tessy France
| | - Igor Bessieres
- Department of Physics Centre Georges François Leclerc Dijon France
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Does CyberKnife improve dose distribution versus IMRT and VMAT on a linear accelerator in low-risk prostate cancer? Radiol Oncol 2022; 56:259-266. [PMID: 35344646 PMCID: PMC9122296 DOI: 10.2478/raon-2022-0010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 01/31/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Hypofractionated stereotactic body radiation therapy (SBRT) for prostate cancer (PCa) can be delivered with the robot-assisted CyberKnife (CK) system or on a linear accelerator using dynamic intensity-modulated radiotherapy (IMRT) or volumetric arc radiotherapy (VMAT). This retrospective study was performed to determine whether CK offers better dose distribution than IMRT and/or VMAT. MATERIALS AND METHODS Treatment plans for three techniques were prepared using the same treatment parameters (36.35 Gy, 7.25 Gy/fr). We evaluated target coverage, conformity index (CI), homogeneity index (HI), gamma index (GI), and organs at risk (OAR) constraints. RESULTS The mean planning target volume (PTV) dose for CK (39.58 Gy) was significantly greater than VMAT or IMRT (both 36.25 Gy). However, CK resulted in a wider dose range (31.48 to 45.89 Gy) vs. VMAT and IMRT (34.6-38.76 Gy). The mean dose to the rectum (V36Gy, mm3) was significantly lower (p < 0.001) in the CK plans (219.78 vs. 519.59 and 422.62, respectively). The mean bladder dose (V37Gy, mm3) was significantly greater for CK (3256 vs. 1090.75 for VMAT and 4.5 for IMRT (p < 0.001). CK yielded significantly better CI (1.07 vs. 1.17 and 1.25 for VMAT and IMRT, respectively; p < 0.01) and HI values (1.27 vs. 1.07 and 1.04; p < 0.01). GI values for the δd = 3mm, δ% = 3% criteria were 99.86 (VMAT), 99.07 (IMRT) and 99.99 (CK). For δd = 2mm, δ% = 2%, the corresponding values were 98.3, 93.35, and 97.12, respectively. CONCLUSIONS For most variables, CK was superior to both VMAT and IMRT. However, dynamic IMRT techniques, especially VMAT, do not differ significantly from CK plans and are therefore acceptable alternatives to CyberKnife.
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Masson I, Bellanger M, Perrocheau G, Mahé MA, Azria D, Pommier P, Mesgouez-Nebout N, Giraud P, Peiffert D, Chauvet B, Dudouet P, Salem N, Noël G, Khalifa J, Latorzeff I, Guérin-Charbonnel C, Supiot S. Cost and Toxicity Comparisons of Two IMRT Techniques for Prostate Cancer: A Micro-Costing Study and Weighted Propensity Score Analysis Based on a Prospective Study. Front Oncol 2022; 11:781121. [PMID: 35087753 PMCID: PMC8787862 DOI: 10.3389/fonc.2021.781121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/10/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Intensity modulated radiation therapy (IMRT) combined with androgen deprivation therapy (ADT) has become the standard treatment for patients with high-risk prostate cancer. Two techniques of rotational IMRT are commonly used in this indication: Volumetric Modulated Arc Therapy (VMAT) and helical tomotherapy (HT). To the best of our knowledge, no study has compared their related costs and clinical effectiveness and/or toxicity in prostate cancer. We aimed to assess differences in costs and toxicity between VMAT and HT in patients with high-risk prostate cancer with pelvic irradiation. MATERIAL AND METHODS We used data from the "RCMI pelvis" prospective multicenter study (NCT01325961) including 155 patients. We used a micro-costing methodology to identify cost differences between VMAT and HT. To assess the effects of the two techniques on total actual costs per patient and on toxicity we used stabilized inverse probability of treatment weighting. RESULTS The mean total cost for HT, €2019 3,069 (95% CI, 2,885-3,285) was significantly higher than the mean cost for VMAT €2019 2,544 (95% CI, 2,443-2,651) (p <.0001). The mean ± SD labor and accelerator cost for HT was €2880 (± 583) and €1978 (± 475) for VMAT, with 81 and 76% for accelerator, respectively. Acute GI and GU toxicity were more frequent in VMAT than in HT (p = .021 and p = .042, respectively). Late toxicity no longer differed between the two groups up to 24 months after completion of treatment. CONCLUSION Use of VMAT was associated with lower costs for IMRT planning and treatment than HT. Similar stabilized long-term toxicity was reported in both groups after higher acute GI and GU toxicity in VMAT. The estimates provided can benefit future modeling work like cost-effectiveness analysis.
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Affiliation(s)
- Ingrid Masson
- Department of Radiation Oncology, Institut de Cancérologie de l’Ouest René Gauducheau, Saint-Herblain, France
| | - Martine Bellanger
- Department of Human and Social Sciences, Institut de Cancérologie de l’Ouest René Gauducheau, Saint-Herblain, France
- UMR CNRS6051, EHESP (Ecole des Hautes Etudes en Santé Publique - School of Public Health), University of Rennes, Rennes, France
| | - Geneviève Perrocheau
- Department of Human and Social Sciences, Institut de Cancérologie de l’Ouest René Gauducheau, Saint-Herblain, France
| | - Marc-André Mahé
- Department of Radiation Oncology, Institut de Cancérologie de l’Ouest René Gauducheau, Saint-Herblain, France
- Department of Radiation Oncology, François Baclesse Cancer Center, Caen, France
| | - David Azria
- Fédération Universitaire d’Oncologie Radiothérapie (FOROM), Institut Régional du Cancer Montpellier (ICM), Université de Montpellier, Institut de Recherche en Cancérologie de Montpellier (IRCM), Montpellier, France
| | - Pascal Pommier
- Department of Radiation Oncology, Léon Bérard Center, Lyon, France
| | - Nathalie Mesgouez-Nebout
- Department of Radiation Oncology, Institut de Cancérologie de l’Ouest Paul Papin, Angers, France
| | - Philippe Giraud
- Department of Radiation Oncology, Georges Pompidou European Hospital, Paris, France
| | - Didier Peiffert
- Department of Radiation Oncology, Lorraine Cancer Institute, Vandœuvre-lès-Nancy, France
| | - Bruno Chauvet
- Department of Radiation Oncology, Sainte Catherine Institute, Avignon, France
| | - Philippe Dudouet
- Department of Radiation Oncology, Pont de Chaume Clinic, Montauban, France
| | - Naji Salem
- Department of Radiation Oncology, Paoli-Calmettes Institute, Marseille, France
| | - Georges Noël
- Department of Radiation Oncology, Cancerology Institute of Strasbourg-Europe, Strasbourg, France
| | - Jonathan Khalifa
- Department of Radiation Oncology, Institut Universitaire du Cancer de Toulouse-Oncopole (IUCT-Oncopole), Toulouse, France
| | - Igor Latorzeff
- Department of Radiation Oncology, Pasteur Clinic, Toulouse, France
| | - Catherine Guérin-Charbonnel
- Clinical Trial Sponsor Unit/Biometry, Institut de Cancérologie de l’Ouest René Gauducheau, Saint-Herblain, France
- Centre de Recherche en Cancérologie et Immunologie Nantes Angers - Center for Research in Cancerology and Immunology Nantes-Angers (CRCINA), Institut National de la Santé et de la Recherche Médicale - National Institute for Health and Medical Research (INSERM) UMR1232, Centre National de la Recherche Scientifique - National Center for Scientific Research (CNRS) ERL6001, University of Nantes, Nantes, France
| | - Stéphane Supiot
- Department of Radiation Oncology, Institut de Cancérologie de l’Ouest René Gauducheau, Saint-Herblain, France
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Siciarz P, McCurdy B, Hanumanthappa N, Van Uytven E. Adaptive radiation therapy strategies in the treatment of prostate cancer patients using hypofractionated VMAT. J Appl Clin Med Phys 2021; 22:7-26. [PMID: 34787360 PMCID: PMC8664140 DOI: 10.1002/acm2.13415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 07/21/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
PURPOSE To perform a comprehensive evaluation of eight adaptive radiation therapy strategies in the treatment of prostate cancer patients who underwent hypofractionated volumetric modulated arc therapy (VMAT) treatment. MATERIAL AND METHODS The retrospective study included 20 prostate cancer patients treated with 40 Gy total dose over five fractions (8 Gy/fraction) using VMAT. Daily cone beam computed tomography images were acquired before the delivery of every fraction and then, with the application of deformable image registration used for the estimation of daily dose, contouring and plan re-optimization. Dosimetric benefits of the various ART strategies were quantified by the comparison of dose and dose-volume metrics derived from treatment planning objectives for original treatment plan and adapted plans with the consideration of target volumes (PTV and CTV) as well as critical structures (bladder, rectum, left, and right femoral heads). RESULTS Percentage difference (ΔD) between planning objectives and delivered dose in the D99% > 4000cGy (CTV) metric was -3.9% for the non-ART plan and 2.1% to 4.1% for ART plans. For D99% > 3800cGy and Dmax < 4280cGy (PTV), ΔD was -11.2% and -6.5% for the non-ART plan as well as -3.9% to -1.6% and -0.2% to 1.8% for ART plans, respectively. For D15% < 3200 cGy and D20% < 2800 cGy (bladder), ΔD was -62.4% and -68.8% for the non-ART plan as well as -60.0% to -57.4% and -67.0% to -64.0% for ART plans. For D15% < 3200 cGy and D20% < 2800 cGy (rectum), ΔD was -11.4% and -8.15% for non-ART plan as well as -14.9% to -9.0% and -11.8% to -5.1% for ART plans. CONCLUSIONS Daily on-line adaptation approaches were the most advantageous, although strategies adapting every other fraction were also impactful while reducing relative workload as well. Offline treatment adaptations were shown to be less beneficial due to increased dose delivered to bladder and rectum compared toother ART strategies.
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Affiliation(s)
- Pawel Siciarz
- Department of Medical PhysicsCancerCare ManitobaWinnipegManitobaCanada
- Department of Physics and AstronomyUniversity of ManitobaWinnipegManitobaCanada
| | - Boyd McCurdy
- Department of Medical PhysicsCancerCare ManitobaWinnipegManitobaCanada
- Department of Physics and AstronomyUniversity of ManitobaWinnipegManitobaCanada
- Department of RadiologyUniversity of ManitobaWinnipegManitobaCanada
| | | | - Eric Van Uytven
- Department of Medical PhysicsCancerCare ManitobaWinnipegManitobaCanada
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Huang C, Yang Y, Panjwani N, Boyd S, Xing L. Pareto Optimal Projection Search (POPS): Automated Radiation Therapy Treatment Planning by Direct Search of the Pareto Surface. IEEE Trans Biomed Eng 2021; 68:2907-2917. [PMID: 33523802 PMCID: PMC8526351 DOI: 10.1109/tbme.2021.3055822] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Radiation therapy treatment planning is a time-consuming, iterative process with potentially high inter-planner variability. Fully automated treatment planning processes could reduce a planner's active treatment planning time and remove inter-planner variability, with the potential to tremendously improve patient turnover and quality of care. In developing fully automated algorithms for treatment planning, we have two main objectives: to produce plans that are 1) Pareto optimal and 2) clinically acceptable. Here, we propose the Pareto optimal projection search (POPS) algorithm, which provides a general framework for directly searching the Pareto front. METHODS Our POPS algorithm is a novel automated planning method that combines two main search processes: 1) gradient-free search in the decision variable space and 2) projection of decision variables to the Pareto front using the bisection method. We demonstrate the performance of POPS by comparing with clinical treatment plans. As one possible quantitative measure of treatment plan quality, we construct a clinical acceptability scoring function (SF) modified from the previously developed general evaluation metric (GEM). RESULTS On a dataset of 21 prostate cases collected as part of clinical workflow, our proposed POPS algorithm produces Pareto optimal plans that are clinically acceptable in regards to dose conformity, dose homogeneity, and sparing of organs-at-risk. CONCLUSION Our proposed POPS algorithm provides a general framework for fully automated treatment planning that achieves clinically acceptable dosimetric quality without requiring active planning from human planners. SIGNIFICANCE Our fully automated POPS algorithm addresses many key limitations of other automated planning approaches, and we anticipate that it will substantially improve treatment planning workflow.
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Gozal F, Gondhowiardjo SA, Kodrat H, Wibowo WE. Dosimetric analysis of three-dimensional conformal radiotherapy, intensity-modulated radiotherapy-step and shoot, helical tomotherapy, and volumetric modulated arc therapy in prostate cancer radiotherapy. J Cancer Res Ther 2021; 17:893-900. [PMID: 34528538 DOI: 10.4103/jcrt.jcrt_57_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Introduction There is limited study comparing dosimetry parameters in detail. In regard to prostate cancer, there are four different techniques, namely three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy-step and shoot (IMRT-SS), IMRT-helical tomotherapy (HT), and volumetric-modulated arc therapy (VMAT). Materials and Methods Experimental study with intervention on ten prostate cancer patients' computed tomography planning data. 78 Gy dose in 39 fractions was given for planning target volume.Experimental study with intervention on ten prostate cancer patients' computed tomography planning data. 78 Gy dose in 39 fractions was given for planning target volume. Results The mean V75 Gy rectum and bladder between 3D-CRT and the other three abovementioned techniques all showed significant results (P < 0.05). V5 Gy remaining volume at risk (RVR) between 3D-CRT versus VMAT and HT, IMRT-SS versus HT, and VMAT versus HT is statistically significant (P < 0.0001). The longest radiation time was done with HT (mean 4.70 ± 0.84 min). Conclusion V75 Gy rectum bladder between 3D-CRT techniques differ significantly compared to the three other techniques and may not be suitable to the implementation of escalation doses. The HT technique produced the highest V5 Gy RVR and needed the highest monitor unit amount and the longest radiation duration. The VMAT technique was considered capable of realizing dose escalation in prostate cancer radiotherapy by minimizing toxicity in the rectum and bladder with the shortest radiation duration.
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Affiliation(s)
- Fenny Gozal
- Radiation Oncology Department, Rumah Sakit Cipto Mangunkusumo, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | | | - Henry Kodrat
- Radiation Oncology Department, Rumah Sakit Cipto Mangunkusumo, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Wahyu Edy Wibowo
- Radiation Oncology Department, Rumah Sakit Cipto Mangunkusumo, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
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Vu E, Pratsinis M, Plasswilm L, Schmid HP, Panje C, Betschart P. Radiotherapy or Surgery? Comparative, Qualitative Assessment of Online Patient Education Materials on Prostate Cancer. Curr Oncol 2021; 28:3420-3429. [PMID: 34590594 PMCID: PMC8482178 DOI: 10.3390/curroncol28050296] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/26/2021] [Accepted: 08/31/2021] [Indexed: 11/16/2022] Open
Abstract
As multiple different treatment options are available for prostate cancer (PCa) and YouTube is commonly used as a source for medical information, we performed a systematic and comparative assessment of available videos guiding patients on their choice for the optimal treatment. An independent search for surgical therapy or radiotherapy of PCa on YouTube was performed and the 40 most viewed videos of both groups were analyzed. The validated DISCERN questionnaire and PEMAT were utilized to evaluate their quality and misinformation. The median overall quality of the videos was found to be low for surgery videos, while radiotherapy videos results reached a moderate quality. The median PEMAT understandability score was 60% (range 0-100%) for radiotherapy and 75% (range 40-100) for surgery videos. The radiotherapy videos contained less misinformation and were judged to be of higher quality. Summarized, the majority of the provided videos offer insufficient quality of content and are potentially subject to commercial bias without reports on possible conflict of interest. Thus, most of available videos on YouTube informing PCa patients about possible treatment methods are not suited for a balanced patient education or as a basis for the patient's decision.
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Affiliation(s)
- Erwin Vu
- Department of Radiation Oncology, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland; (E.V.); (L.P.); (C.P.)
| | - Manolis Pratsinis
- Department of Urology, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland; (M.P.); (H.-P.S.)
| | - Ludwig Plasswilm
- Department of Radiation Oncology, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland; (E.V.); (L.P.); (C.P.)
- Faculty of Medicine, University of Bern, 3008 Bern, Switzerland
| | - Hans-Peter Schmid
- Department of Urology, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland; (M.P.); (H.-P.S.)
| | - Cédric Panje
- Department of Radiation Oncology, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland; (E.V.); (L.P.); (C.P.)
- Faculty of Medicine, University of Bern, 3008 Bern, Switzerland
| | - Patrick Betschart
- Department of Urology, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland; (M.P.); (H.-P.S.)
- Correspondence: ; Tel.: +41-71-494-914-16
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Aland T, Jones M, Aho J, Kairn T, Trapp J. Modelling of a novel technique to improve the visualisation of implanted fiducial markers for intra-fraction MV imaging of prostate VMAT targets. Biomed Phys Eng Express 2021; 7. [PMID: 34265752 DOI: 10.1088/2057-1976/ac14d2] [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: 05/27/2021] [Accepted: 07/15/2021] [Indexed: 11/11/2022]
Abstract
Purpose. This study explored a novel technique to improve the MV imaging based fiducial visibility for a cohort of prostate radiotherapy patients, without compromising the original treatment plan. The study also compared these results to visibility using single MLC control points, as well as short arcs.Methods. Geometric data from 68 prostate radiotherapy treatments, each with implanted gold fiducials, was retrospectively analysed. Fiducials were contoured for each patient, and conventional and SBRT treatment plans were generated using a VMAT technique. Using an in-house script, fiducial contours were projected onto the VMAT MLC control points. Resulting data was assessed to determine whether the fiducial contours were theoretically visible for single MLC control points and groups of MLC control points (short arcs), both being surrogates for intra-fraction MV imaging. Using this data, a theoretical quadrant technique was investigated that assessed the region surrounding each fiducial to determine if visualisation would theoretically improve.Results. Using a conventional treatment type, mean fiducial visibility for single MLC control points across the patient cohort ranged from 2.5% up to 17.8%. For SBRT, fiducial visibility ranged from 1.8% up to 19.7%. For short arcs, fiducial visibility for conventional treatment types ranged from 5.9% up to 20.7%. For SBRT, fiducial visibility ranged from 4.6% up to 23.1%. When the novel fiducial quadrant technique was used, theoretical visibility improved two-fold, from 22.7% up to 52.5% and from 24.7% up to 55.3% for conventional and SBRT treatment types respectively.Conclusions. Fiducial visibility was assessed for a cohort of VMAT prostate patients. Using the novel quadrant technique, it was demonstrated that theoretical visualisation and localisation of the implanted fiducials could be improved two-fold, without sacrificing treatment plan quality.
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Affiliation(s)
- Trent Aland
- Icon Group, 22 Cordelia Street, South Brisbane Qld 4101, Australia.,School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane Qld 4000, Australia
| | - Mark Jones
- Icon Group, 22 Cordelia Street, South Brisbane Qld 4101, Australia
| | - Jari Aho
- Varian Medical Systems, Paciuksenkatu 21, 00270 Helsinki, Finland
| | - Tanya Kairn
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane Qld 4000, Australia.,Cancer Care Services, Royal Brisbane and Women's Hospital, Butterfield Street, Herston Qld 4029, Australia
| | - Jamie Trapp
- School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane Qld 4000, Australia
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Incidence and dosimetric predictive factors of late rectal toxicity after low-dose-rate brachytherapy combined with volumetric modulated arc therapy in high-risk prostate cancer at a single institution: Retrospective study. Brachytherapy 2021; 20:584-594. [PMID: 33485811 DOI: 10.1016/j.brachy.2020.12.004] [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: 10/12/2020] [Revised: 11/20/2020] [Accepted: 12/12/2020] [Indexed: 11/23/2022]
Abstract
PURPOSE The purpose of this study is to investigate the incidence of rectal toxicity and to identify the associated dosimetric predictive parameters after I-125 seed low-dose-rate brachytherapy (LDR-BT) combined with volumetric modulated arc therapy (VMAT) and dose constraints. METHODS AND MATERIALS In total, 110 patients with high-risk prostate cancer received 110 Gy LDR-BT, followed by 45 Gy VMAT. Rectal toxicity was recorded according to Common Terminology Criteria for Adverse Events v.4.03. The dosimetric factors associated with LDR-BT and VMAT were analyzed to determine their relationship with rectal toxicity. Receiver operating characteristic (ROC) curve analysis was performed for ≥ grade 2 (G2) rectal toxicity prediction. RESULTS The follow-up duration was 10.1-115.2 months (median 60.5 months). Seven patients had G2 rectal hemorrhage, and none of the patients had grade 3 rectal hemorrhage. In the univariate analysis, the rectal volume receiving 100% of the prescribed dose (rV100) (p < 0.001), the dose covering 2 cc of the rectum (rD2cc) during LDR-BT (p = 0.002), and the combined rD2cc during LDR-BT and VMAT (p = 0.001) were identified as predictors of G2 rectal hemorrhage. In the ROC curve analysis, the cutoff value was 0.46 cc for rV100, 74.0 Gy for rD2cc, and 86.8 GyEQD2 for combined rD2cc. CONCLUSION Predictors of late ≥ G2 rectal hemorrhage are rV100, rD2cc, and combined rD2cc. The incidence of rectal toxicity is low and acceptable in this setting and is highly dependent on the rectal dose of LDR-BT. The use of higher-quality LDR-BT and VMAT dose constraints may further reduce the rate of rectal hemorrhage.
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Aynaci O, Çolak F, Serdar L, Yöney A. Dosimetric comparison of three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and volumetric modulated arc therapy in high-risk prostate cancer. JOURNAL OF RADIATION AND CANCER RESEARCH 2021. [DOI: 10.4103/jrcr.jrcr_34_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Mannerberg A, Persson E, Jonsson J, Gustafsson CJ, Gunnlaugsson A, Olsson LE, Ceberg S. Dosimetric effects of adaptive prostate cancer radiotherapy in an MR-linac workflow. Radiat Oncol 2020; 15:168. [PMID: 32650811 PMCID: PMC7350593 DOI: 10.1186/s13014-020-01604-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/23/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The purpose was to evaluate the dosimetric effects in prostate cancer treatment caused by anatomical changes occurring during the time frame of adaptive replanning in a magnetic resonance linear accelerator (MR-linac) workflow. METHODS Two MR images (MR1 and MR2) were acquired with 30 min apart for each of the 35 patients enrolled in this study. The clinical target volume (CTV) and organs at risk (OARs) were delineated based on MR1. Using a synthetic CT (sCT), ultra-hypofractionated VMAT treatment plans were created for MR1, with three different planning target volume (PTV) margins of 7 mm, 5 mm and 3 mm. The three treatment plans of MR1, were recalculated onto MR2 using its corresponding sCT. The dose distribution of MR2 represented delivered dose to the patient after 30 min of adaptive replanning, omitting motion correction before beam on. MR2 was registered to MR1, using deformable registration. Using the inverse deformation, the structures of MR1 was deformed to fit MR2 and anatomical changes were quantified. For dose distribution comparison the dose distribution of MR2 was warped to the geometry MR1. RESULTS The mean center of mass vector offset for the CTV was 1.92 mm [0.13 - 9.79 mm]. Bladder volume increase ranged from 12.4 to 133.0% and rectum volume difference varied between -10.9 and 38.8%. Using the conventional 7 mm planning target volume (PTV) margin the dose reduction to the CTV was 1.1%. Corresponding values for 5 mm and 3 mm PTV margin were 2.0% and 4.2% respectively. The dose to the PTV and OARs also decreased from D1 to D2, for all PTV margins evaluated. Statistically significant difference was found for CTV Dmin between D1 and D2 for the 3 mm PTV margin (p < 0.01). CONCLUSIONS A target underdosage caused by anatomical changes occurring during the reported time frame for adaptive replanning MR-linac workflows was found. Volume changes in both bladder and rectum caused large prostate displacements. This indicates the importance of thorough position verification before treatment delivery and that the workflow needs to speed up before introducing margin reduction.
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Affiliation(s)
- Annika Mannerberg
- Department of Medical Radiation Physics, Lund University, Lund, Sweden.
| | - Emilia Persson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Joakim Jonsson
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - Christian Jamtheim Gustafsson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Adalsteinn Gunnlaugsson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Lars E Olsson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Sofie Ceberg
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
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Dosimetric evaluation of whole-pelvis radiation therapy of prostate cancers: clinical experience. JOURNAL OF RADIOTHERAPY IN PRACTICE 2020. [DOI: 10.1017/s1460396920000461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractBackground:The standard treatment modalities for prostate cancer include surgery, chemotherapy, hormonal therapy and radiation therapy or any combination depending on the stage of the tumour. Radiation therapy is a common and effective treatment modality for low-intermediate-risk patients with localised prostate cancer, to treat the intact prostate and seminal vesicles or prostate bed post prostatectomy. However, for high-risk patients with lymph node involvement, treatment with radiation will usually include treatment of the whole pelvis to cover the prostate and seminal vesicles or prostate bed and the pelvic lymph nodes followed by a boost delivery dose to the prostate and seminal vesicles or prostate bed.Materials and Methods:We retrospectively analysed the treatment plans for 179 prostate cancer patients treated at the cancer centre with the volumetric-modulated arc therapy (VMAT) technique via RapidArc using 6 MV photon beam. Patients were either treated with a total prescription dose of 78 Gy in 39 fractions for patients with intact prostate or 66 Gy in 33 fractions for post prostatectomy patients.Results:There were 114 (64%) patients treated with 78 Gy/39 and 65 (36%) treated with 66 Gy/34. The mean homogeneity index (HI), conformity index (CI) and uniformity index (UI) for the PTV-primary of patients treated with 78 Gy are 0.06 ± 0.01, 1.04 ± 0.01 and 0.99 ± 0.01, respectively, and the corresponding mean values for patients treated with 66 Gy are 0.06 ± 0.02, 1.05 ± 0.01 and 0.99 ± 0.01, respectively. The mean PTV-primary V95%, V100% and V105% are 99.5 ± 0.5%, 78.8 ± 12.2% and 0.1 ± 0.5%, respectively, for patients treated with 78 Gy and 99.3 ± 0.9%, 78.1 ± 10.6% and 0.1 ± 0.4%, respectively, for patients treated with 66 Gy. The rectal V50Gy, V65Gy, V66.6Gy, V70Gy, V75Gy and V80Gy are 26.8 ± 9.1%, 14.2 ± 5.3%, 13.1 ± 5.0%, 10.8 ± 4.3%, 6.9 ± 3.1% and 0.1 ± 0.1%, respectively, for patients treated with 78 Gy and 33.7 ± 8.4%, 14.1 ± 4.5%, 6.7 ± 4.5%, 0.0 ± 0.2%, 0.0% and 0.0%, respectively, for patients treated with 66 Gy.Conclusion:The use of VMAT technique for radiation therapy of high-risk prostate cancer patients is an efficient and reliable method for achieving superior dose conformity, uniformity and homogeneity to the PTV and minimal doses to the organs at risk. Results from this study provide the basis for the development and implementation of consistent treatment criteria in radiotherapy programs, have the potential to establish an evaluation process to define a consistent, standardised and transparent treatment path for all patients that reduces significant variations in the acceptability of treatment plans and potentially improve patient standard of care.
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Urethra-Sparing Stereotactic Body Radiation Therapy for Prostate Cancer: Quality Assurance of a Randomized Phase 2 Trial. Int J Radiat Oncol Biol Phys 2020; 108:1047-1054. [PMID: 32535161 DOI: 10.1016/j.ijrobp.2020.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 05/12/2020] [Accepted: 06/01/2020] [Indexed: 02/05/2023]
Abstract
PURPOSE To present the radiation therapy quality assurance results from a prospective multicenter phase 2 randomized trial of short versus protracted urethra-sparing stereotactic body radiation therapy (SBRT) for localized prostate cancer. METHODS AND MATERIALS Between 2012 and 2015, 165 patients with prostate cancer from 9 centers were randomized and treated with SBRT delivered either every other day (arm A, n = 82) or once a week (arm B, n = 83); 36.25 Gy in 5 fractions were prescribed to the prostate with (n = 92) or without (n = 73) inclusion of the seminal vesicles (SV), and the urethra planning-risk volume received 32.5 Gy. Patients were treated either with volumetric modulated arc therapy (VMAT; n = 112) or with intensity modulated radiation therapy (IMRT; n = 53). Deviations from protocol dose constraints, planning target volume (PTV) homogeneity index, PTV Dice similarity coefficient, and number of monitor units for each treatment plan were retrospectively analyzed. Dosimetric results of VMAT versus IMRT and treatment plans with versus without inclusion of SV were compared. RESULTS At least 1 major protocol deviation occurred in 51 patients (31%), whereas none was observed in 41. Protocol violations were more frequent in the IMRT group (P < .001). Furthermore, the use of VMAT yielded better dosimetric results than IMRT for urethra planning-risk volume D98% (31.1 vs 30.8 Gy, P < .0001), PTV D2% (37.9 vs 38.7 Gy, P < .0001), homogeneity index (0.09 vs 0.10, P < .0001), Dice similarity coefficient (0.83 vs 0.80, P < .0001), and bladder wall V50% (24.5% vs 33.5%, P = .0001). To achieve its goals volumetric modulated arc therapy required fewer monitor units than IMRT (2275 vs 3378, P <.0001). The inclusion of SV in the PTV negatively affected the rectal wall V90% (9.1% vs 10.4%, P = .0003) and V80% (13.2% vs 15.7%, P = .0003). CONCLUSIONS Protocol deviations with potential impact on tumor control or toxicity occurred in 31% of patients in this prospective clinical trial. Protocol deviations were more frequent with IMRT. Prospective radiation therapy quality assurance protocols should be strongly recommended for SBRT trials to minimize potential protocol deviations.
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Matar FS, Wilkinson D, Davis J, Biasi G, Causer T, Fuduli I, Brace O, Stansook N, Carolan M, Rosenfeld AB, Petasecca M. Quality assurance of VMAT on flattened and flattening filter-free accelerators using a high spatial resolution detector. J Appl Clin Med Phys 2020; 21:44-52. [PMID: 32277745 PMCID: PMC7324694 DOI: 10.1002/acm2.12864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 01/02/2023] Open
Abstract
PURPOSE This study investigated the use of high spatial resolution solid-state detectors (DUO and Octa) combined with an inclinometer for machine-based quality assurance (QA) of Volumetric Modulated Arc Therapy (VMAT) with flattened and flattening filter-free beams. METHOD The proposed system was inserted in the accessory tray of the gantry head of a Varian 21iX Clinac and a Truebeam linear accelerator. Mutual dependence of the dose rate (DR) and gantry speed (GS) was assessed using the standard Varian customer acceptance plan (CAP). The multi-leaf collimator (MLC) leaf speed was evaluated under static gantry conditions in directions parallel and orthogonal to gravity as well as under dynamic gantry conditions. Measurements were compared to machine log files. RESULTS DR and GS as a function of gantry angle were reconstructed using the DUO/inclinometer and in agreement to within 1% with the machine log files in the sectors of constant DR and GS. The MLC leaf speeds agreed with the nominal speeds and those extracted from the machine log files to within 0.03 cm s-1 . The effect of gravity on the leaf motion was only observed when the leaves traveled faster than the nominal maximum velocity stated by the vendor. Under dynamic gantry conditions, MLC leaf speeds ranging between 0.33 and 1.42 cm s-1 were evaluated. Comparing the average MLC leaf speeds with the machine log files found differences between 0.9% and 5.7%, with the largest discrepancy occurring under conditions of fastest leaf velocity, lowest DR and lowest detector signal. CONCLUSIONS The investigation on the use of solid-state detectors in combination with an inclinometer has demonstrated the capability to provide efficient and independent verification of DR, GS, and MLC leaf speed during dynamic VMAT delivery. Good agreement with machine log files suggests the detector/inclinometer system is a useful tool for machine-specific VMAT QA.
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Affiliation(s)
- F. S. Matar
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
| | - D. Wilkinson
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
- Illawarra Cancer Care CentreWollongong HospitalWollongongAustralia
| | - J. Davis
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
- Illawarra Health and Medical Research Institute – IHMRIWollongongAustralia
| | - G. Biasi
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
| | - T. Causer
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
- Illawarra Cancer Care CentreWollongong HospitalWollongongAustralia
| | - I. Fuduli
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
| | - O. Brace
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
| | - N. Stansook
- Department of RadiologyFaculty of MedicineMahidol UniversityBangkokThailand
| | - M. Carolan
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
- Illawarra Cancer Care CentreWollongong HospitalWollongongAustralia
- Illawarra Health and Medical Research Institute – IHMRIWollongongAustralia
| | - A. B. Rosenfeld
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
- Illawarra Health and Medical Research Institute – IHMRIWollongongAustralia
| | - Marco Petasecca
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongAustralia
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Cross-modality applicability of rectal normal tissue complication probability models from photon- to proton-based radiotherapy. Radiother Oncol 2020; 142:253-260. [DOI: 10.1016/j.radonc.2019.09.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 09/20/2019] [Accepted: 09/21/2019] [Indexed: 11/21/2022]
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K BT, Ganesh KM, A P. Is High Definition MLC Dosimetrically Superior to Standard Definition MLC for SIB-SBRT for Carcinoma Prostate. Asian Pac J Cancer Prev 2019; 20:3817-3823. [PMID: 31870127 PMCID: PMC7173375 DOI: 10.31557/apjcp.2019.20.12.3817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/28/2019] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE The study was conducted to quantitatively evaluate the dosimetric effects of high definition (2.5 mm) and standard definition (5.0 mm) MLC on the quality of SBRT plans using SIB-IMRT and SIB-VMAT technique for carcinoma prostate and also to evaluate the dosimetric advantage of one technique over the other. MATERIALS AND METHODS Seventeen annonymized planning CT data sets were used to generate plans for both VMAT and IMRT techniques using 2.5 mm and 5.0 mm MLC.The prescription to the nodule was 45Gy in 5 fractions and to the prostate was 35Gy in 5 fractions.CI, GI, D2%, D98%, D50% and V95% for target; D2%, Dmean, V80%, V20% for OAR's; V5% of the irradiated volume, and delivered MU's were analyzed.An independent t-test was used to compare the plans. Patient specific QA for all plans were also performed and analyzed. RESULTS Minor difference in dosimetric indices was observed between 2.5mm and 5mm MLC VMAT plans, except D2% (PTV35) and D98% (GTV45) were better in 2.5mm MLC plans (p.
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Affiliation(s)
- Bijina T K
- Research and Development center, Bharathiar University, Coimbatore,
- Department of Radiation Oncology, Healthcare Global Enterprises,
| | - K M Ganesh
- Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bangalore, India.
| | - Pichandi A
- Department of Radiation Oncology, Healthcare Global Enterprises,
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Hatano K, Tohyama N, Kodama T, Okabe N, Sakai M, Konoeda K. Current status of intensity‐modulated radiation therapy for prostate cancer: History, clinical results and future directions. Int J Urol 2019; 26:775-784. [DOI: 10.1111/iju.14011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 04/07/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Kazuo Hatano
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Naoki Tohyama
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Takashi Kodama
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Naoyuki Okabe
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Mitsuhiro Sakai
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
| | - Koichi Konoeda
- Division of Radiation Oncology Tokyo‐Bay Advanced Imaging & Radiation Oncology Clinic/Makuhari Chiba Japan
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Chow JCL, Jiang R, Xu L. Dosimetric and radiobiological comparison of prostate VMAT plans optimized using the photon and progressive resolution algorithm. Med Dosim 2019; 45:14-18. [PMID: 31103251 DOI: 10.1016/j.meddos.2019.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 02/26/2019] [Accepted: 04/12/2019] [Indexed: 11/20/2022]
Abstract
This study compared the dosimetric and radiobiological parameters of prostate volumetric modulated arc therapy (VMAT) plans using different prescriptions optimized by the photon optimization (PO) and progressive resolution optimization (PRO) algorithm. A total of 20 prostate patients were selected retrospectively and divided into 2 groups of VMAT plans using prescriptions of 60 Gy/20 fx and 79 Gy/38 fx. Inverse treatment planning optimized by the PO and PRO algorithm based on the dual-arc technique was carried out by the Eclipse treatment planning system. The maximum dose, minimum dose, mean dose, dose-volume points, and dose-volume indices of the targets and organs at risk (OAR) were calculated from the plans. In addition, radiobiological parameters such as tumor control probability (TCP), normal tissue complication probability (NTCP), and equivalent uniform dose (EUD) of the targets and OAR were determined based on their dose-volume histograms (DVHs). A paired Student's t-test was carried out to compare the difference between mean dose-volume points, radiobiological parameters, and dose-volume indices. Two-tailed p < 0.05 was defined as having statistical difference. For prostate VMAT plans optimized by the PO algorithm, equal or slightly larger mean dose and TCP of the PTV (1% for 60 Gy/20 fx and 0.2% for 78 Gy/39 fx) were found by comparing to the PRO. These were followed by finding the slightly larger conformity index (CI; 0.927 vs 0.895 and 0.910 vs 0.904), larger or equal homogeneity index (HI; 0.054 vs 0.052 and 0.058 vs 0.058), and smaller gradient index (GI; 1.366 vs 2.288 and 1.585 vs 1.742) of the PTV using plans optimized by the PO vs PRO using prescriptions of 60 Gy/20 fx and 78 Gy/39 fx. For the OAR, we found that the mean doses, NTCPs, and EUDs of the rectum, bladder, and femur were slightly larger for plans optimized by the PO algorithm compared to the PRO, though both optimization algorithms satisfied all the dose-volume criteria and objectives in the inverse planning. Both the PO and PRO algorithm can generate prostate VMAT plans fulfilling the required dose-volume criteria. It is concluded that plans optimized by the PO algorithm can produce prostate plan with very similar quality compared to PRO.
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Affiliation(s)
- James C L Chow
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1X6, Canada; Department of Radiation Oncology, University of Toronto, Toronto, ON M5S 3E2, Canada.
| | - Runqing Jiang
- Medical Physics Department, Grand River Regional Cancer Centre, Kitchener, ON N2G 1G3, Canada; Department of Physics, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Lu Xu
- Department of Medical Biophysics, Western University, London, ON N6A 3K7, Canada
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Wang S, Zhou L, Xue J, Lan J, Deng L, Yi T, Lu Y. Comparison of biologically effective dose for treatment planning in the fixed-beam intensity-modulated radiotherapy and the volumetric-modulated arc therapy for the typical types of cancer. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2018.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Sun WZ, Chen L, Yang X, Wang B, Deng XW, Huang XY. Comparison of treatment plan quality of VMAT for esophageal carcinoma with: flattening filter beam versus flattening filter free beam. J Cancer 2018; 9:3263-3268. [PMID: 30271485 PMCID: PMC6160692 DOI: 10.7150/jca.26044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 08/02/2018] [Indexed: 12/11/2022] Open
Abstract
Purpose: To investigate the difference in treatment plan quality of volumetric modulated arc treatment (VMAT) for esophageal carcinoma with flattening filter beam (FF) and flattening filter free beam (FFF). Material and methods: A total of fifty-six treatment plans were generated for twenty eight esophageal carcinoma patients with flattening filter beam and flattening filter free beam, using same optimal parameters. The homogeneity index (HI) and conformal index (CI) of targets, and some special points on Dose-Volume Histogram (DVH) curves were used to compare the plan quality. The coverage volumes of 45 Gy, 30 Gy and 20 Gy outside targets (V45Gy, V30Gy and V20Gy ) were used to compare the targets peripheral dose. The MU numbers, measured delivery time and averaged dose rates were used to evaluate the delivery efficiency of treatment plans. Results: A significant decreasing in peripheral dose around targets was found using FFF beams while the dose distributions in targets were equivalent to the plans with FF beams. V45Gy, V30Gy and V20Gy were decreased by 6.46%, 88.18% and 4.40%, respectively. A significant increase in MUs and decrease in treatment time were also found in delivery test. The average MUs was increased by 21.83% and the average treatment time was reduced by down to 11.9%. Conclusions: For esophageal carcinoma, the research showed that the treatment plans with FFF beams could get comparable dose distribution in targets and could significantly reduce the peripheral dose around targets compared to the plans with FF beams.
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Affiliation(s)
| | | | | | | | | | - Xiao-yan Huang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China
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Dosimetric variations in calculation grid size in prostate VMAT: a dose-volume histogram analysis using the Gaussian error function. JOURNAL OF RADIOTHERAPY IN PRACTICE 2018. [DOI: 10.1017/s1460396917000619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractBackgroundVarying the calculation grid size can change the results of dose-volume and radiobiological parameters in a treatment plan, and therefore has an impact on the treatment planning quality assurance.PurposeThis study investigated the dosimetric influence of the calculation grid size variation in the prostate volumetric modulated arc therapy (VMAT) plan.Methods and materialsDose distributions of 10 prostate VMAT plans were acquired using calculation grid sizes of 1–5 mm. Dose-volume histogram (DVH) analysis was carried out to determine the dose-volume variation corresponding to the grid size change using the Gaussian error function (GEF). At the same time, dose-volume points, dose-volume parameters and radiobiological parameters were calculated based on DVHs of targets and organs at risk (OARs) for each grid size.ResultsComparing percentage variations of GEF parameters between the planning target volume (PTV) and clinical target volume (CTV), GEF parameters of the PTV were found varied more significantly than the CTV. This resulted in larger variations of dose-volume (%ΔCI=40·02 versus 13·55%, %ΔHI=12·45 versus 2·93% and %ΔGI=0·22 versus 0·06%) and radiobiological parameters (%ΔTCP=0·61 versus 0·25% and %ΔEUD=2·11 versus 0·26%) of the PTV compared with CTV. For OARs, the rectal wall showed a larger dose-volume variation than the rectum. However, similar dose-volume variation due to grid size change was not found in the bladder, bladder wall and femur.ConclusionsKnowing the dosimetric variation in this study is important to the radiotherapy staff in the quality assurance for the prostate VMAT planning.
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Dose-volume and radiobiological dependence on the calculation grid size in prostate VMAT planning. Med Dosim 2018; 43:383-389. [PMID: 29373184 DOI: 10.1016/j.meddos.2017.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 09/27/2017] [Accepted: 12/15/2017] [Indexed: 02/03/2023]
Abstract
This study evaluated the effects of dose-volume and radiobiological dependence on the calculation grid size in prostate volumetric-modulated arc therapy (VMAT) planning. Ten patients with prostate cancer were selected for this retrospective treatment planning study. Prostate VMAT plans were created for the patients using the 6 MV photon beam produced by a Varian TrueBEAM linac with the calculation grid size equal to 1, 2, 2.5, 3, 4, and 5 mm. Dose-volume histograms (DVHs) of targets and organs at risk were generated for different grid sizes. We calculated the radiobiological parameters of the tumor control probability (TCP) of clinical target volume (CTV) and planning target volume (PTV), and the normal tissue complication probability (NTCP) of organs at risk (rectal wall, rectum, bladder wall, bladder, left femur, and right femur). The homogeneity, conformity, and gradient indexes of CTV and PTV were calculated for different grid sizes. The TCP of PTV was found decreasing with a rate of 0.06%/mm when the calculation grid size increased from 1 to 5 mm. On the other hand, both NTCPs of rectal wall and rectum were found decreasing with rates of 0.03%/mm and 0.05%/mm, respectively, with an increase of grid size. The homogeneity index of PTV increased with a rate of 0.57/mm of the calculation grid size, whereas the conformity index of PTV decreased with a rate of 0.0075/mm. The gradient index of PTV was found increasing with a rate equal to 0.05/mm. In prostate VMAT planning, variations of dose-volume and radiobiological parameters with calculation grid size on PTV, rectal wall, and rectum were more significant than those of CTV and other organs at risk such as bladder wall, bladder, and femurs. Results in this study are important in the treatment planning quality assurance when the calculation grid size is varied to compromise a shorter dose computing time.
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Tempel DG, Brodin NP, Tomé WA. On the Inclusion of Short-distance Bystander Effects into a Logistic Tumor Control Probability Model. Cureus 2018. [PMID: 29515941 PMCID: PMC5832408 DOI: 10.7759/cureus.2012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Currently, interactions between voxels are neglected in the tumor control probability (TCP) models used in biologically-driven intensity-modulated radiotherapy treatment planning. However, experimental data suggests that this may not always be justified when bystander effects are important. We propose a model inspired by the Ising model, a short-range interaction model, to investigate if and when it is important to include voxel to voxel interactions in biologically-driven treatment planning. This Ising-like model for TCP is derived by first showing that the logistic model of tumor control is mathematically equivalent to a non-interacting Ising model. Using this correspondence, the parameters of the logistic model are mapped to the parameters of an Ising-like model and bystander interactions are introduced as a short-range interaction as is the case for the Ising model. As an example, we apply the model to study the effect of bystander interactions in the case of radiation therapy for prostate cancer. The model shows that it is adequate to neglect bystander interactions for dose distributions that completely cover the treatment target and yield TCP estimates that lie in the shoulder of the dose response curve. However, for dose distributions that yield TCP estimates that lie on the steep part of the dose response curve or for inhomogeneous dose distributions having significant hot and/or cold regions, bystander effects may be important. Furthermore, the proposed model highlights a previously unexplored and potentially fruitful connection between the fields of statistical mechanics and tumor control probability/normal tissue complication probability modeling.
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Affiliation(s)
- David G Tempel
- Department of Radiation Oncology, Montefiore Medical Center/Albert Einstein College of Medicine
| | - N Patrik Brodin
- Department of Radiation Oncology, Montefiore Medical Center/Albert Einstein College of Medicine
| | - Wolfgang A Tomé
- Department of Radiation Oncology, Montefiore Medical Center/Albert Einstein College of Medicine
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Ren W, Sun C, Lu N, Xu Y, Han F, Liu YP, Dai J. Dosimetric comparison of intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy in patients with prostate cancer: a meta-analysis. J Appl Clin Med Phys 2016; 17:254-262. [PMID: 27929498 PMCID: PMC5690508 DOI: 10.1120/jacmp.v17i6.6464] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 08/13/2016] [Accepted: 08/10/2016] [Indexed: 11/23/2022] Open
Abstract
Intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) are two main radiotherapy techniques. The aim of this study is to explore which is the preferred technique in prostate treatment through the related publica-tions and meta-analysis. Two authors independently identified all relevant articles available regarding eligibility criteria on PubMed, Embase, and Cochrane Library databases until December 2015. Publication bias was evaluated with funnel plot, and statistical analyses were performed with Stata software. P < 0.05 was thought statistically significant. Ten studies comprised a total of 110 patients; in total 110 IMRT plans and 110 VMAT plans that were included in this study. V40, V60, and V70 of rectum were significantly decreased in VMAT than in IMRT. However, V50 of rectum and V40, V50, V60, V70 of bladder had no statistical differences between IMRI and VMAT plans. Compared with IMRT, the treatment time and MUs of VMAT were significantly lower. VMAT protects rectum better than IMRT and improves the delivery efficiency. VMAT may be the preferred modality for treating prostate cancer.
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Affiliation(s)
- Wenting Ren
- Cancer Hospital, National Cancer Center, Chinese Academy of Medical Sciences and Peking Union Medical College.
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Biegała M, Hydzik A. Analysis of dose distribution in organs at risk in patients with prostate cancer treated with the intensity-modulated radiation therapy and arc technique. J Med Phys 2016; 41:198-204. [PMID: 27651567 PMCID: PMC5019039 DOI: 10.4103/0971-6203.189490] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
This study describes a comparative analysis of treatment plans in 48 patients with prostate cancer treated with ionizing radiation. Each patient was subjected to the intensity-modulated radiation therapy (IMRT) and arc technique. In each treatment plan, the organs at risk were assessed: the urinary bladder, rectum and heads of the femur, as well as the volume of normal tissue. The following features were compared: treatment time, conformity indices for the planning target volume, mean doses and standard deviation in organs at risk, and organ volumes for each particular dose. The treatment period in the arc technique is 13.7% shorter than in the IMRT technique. Comparing the results of the IMRT and arc techniques (arc vs. IMRT), the mean values were 29.21 ± 12.91 Gy versus 28.36 ± 13.79 Gy for the bladder, 20.36 ± 3.16 Gy versus 18.17 ± 5.11 Gy for the right femoral head, and 18.98 ± 3.28 Gy versus 16.67 ± 5.15 Gy for the left femoral head. For the rectum, lower values were obtained after application of the arc technique, not the IMRT technique: 35.84 ± 12.28 Gy versus 35.90 ± 13.05 Gy. The results indicate that the applied therapy has a statistically significant influence on the volume for a particular dose with regard to the urinary bladder. It is advisable to apply the IMRT technique to patients who need the femur heads and urinary bladder protected by exposing them to low irradiation doses.
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Affiliation(s)
- Michał Biegała
- Department of Medical Imaging Technology, Faculty of Biomedical Sciences and Postgraduate Training, Medical University of Lodz, 90-251, Lodz, Poland; Department of Medical Physics, Regional Cancer Center, Copernicus Memorial Hospital of Lodz, 93-513 Lodz, Poland
| | - Adam Hydzik
- Department of Medical Physics, Regional Cancer Center, Copernicus Memorial Hospital of Lodz, 93-513 Lodz, Poland
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Khan MI, Jiang R, Kiciak A, Ur Rehman J, Afzal M, Chow JCL. Dosimetric and radiobiological characterizations of prostate intensity-modulated radiotherapy and volumetric-modulated arc therapy: A single-institution review of ninety cases. J Med Phys 2016; 41:162-8. [PMID: 27651562 PMCID: PMC5019034 DOI: 10.4103/0971-6203.189479] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
This study reviewed prostate volumetric-modulated arc therapy (VMAT) plans with intensity-modulated radiotherapy (IMRT) plans after prostate IMRT technique was replaced by VMAT in an institution. Characterizations of dosimetry and radiobiological variation in prostate were determined based on treatment plans of 40 prostate IMRT patients (planning target volume = 77.8–335 cm3) and 50 VMAT patients (planning target volume = 120–351 cm3) treated before and after 2013, respectively. Both IMRT and VMAT plans used the same dose-volume criteria in the inverse planning optimization. Dose-volume histogram, mean doses of target and normal tissues (rectum, bladder and femoral heads), dose-volume points (D99% of planning target volume; D30%, D50%, V30 Gy and V35 Gy of rectum and bladder; D5%, V14 Gy, V22 Gy of femoral heads), conformity index (CI), homogeneity index (HI), gradient index (GI), prostate tumor control probability (TCP), and rectal normal tissue complication probability (NTCP) based on the Lyman-Burman-Kutcher algorithm were calculated for each IMRT and VMAT plan. From our results, VMAT plan was found better due to its higher (1.05%) CI, lower (0.83%) HI and (0.75%) GI than IMRT. Comparing doses in normal tissues between IMRT and VMAT, it was found that IMRT mostly delivered higher doses of about 1.05% to the normal tissues than VMAT. Prostate TCP and rectal NTCP were found increased (1%) for VMAT than IMRT. It is seen that VMAT technique can decrease the dose-volume evaluation criteria for the normal tissues. Based on our dosimetric and radiobiological results in treatment plans, it is concluded that our VMAT implementation could produce comparable or slightly better target coverage and normal tissue sparing with a faster treatment time in prostate radiotherapy.
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Affiliation(s)
| | - Runqing Jiang
- Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, Canada; Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada
| | - Alexander Kiciak
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada
| | | | - Muhammad Afzal
- Department of Physics, Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - James C L Chow
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Canada
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Beech R, Burgess K, Stratford J. Process evaluation of treatment times in a large radiotherapy department. Radiography (Lond) 2016. [DOI: 10.1016/j.radi.2016.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Dosimetric comparison between the prostate intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans using the planning target volume (PTV) dose–volume factor. JOURNAL OF RADIOTHERAPY IN PRACTICE 2016. [DOI: 10.1017/s1460396916000194] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractBackgroundWe demonstrated that our proposed planning target volume (PTV) dose–volume factor (PDVF) can be used to evaluate the PTV dose coverage between the intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans based on 90 prostate patients.PurposePDVF were determined from the prostate IMRT and VMAT plans to compare their variation of PTV dose coverage. Comparisons of the PDVF with other plan evaluation parameters such as D5%, D95%, D99%, Dmean, conformity index (CI), homogeneity index (HI), gradient index (GI) and prostate tumour control probability (TCP) were carried out.Methods and materialsProstate IMRT and VMAT plans using the 6 MV photon beams were created from 40 and 50 patients, respectively. Dosimetric indices (CI, HI and GI), dose–volume points (D5%, D95%, D99% and Dmean) and prostate TCP were calculated according to the PTV dose–volume histograms (DVHs) of the plans. All PTV DVH curves were fitted using the Gaussian error function (GEF) model. The PDVF were calculated based on the GEF parameters.ResultsFrom the PTV DVHs of the prostate IMRT and VMAT plans, the average D99% of the PTV for IMRT and VMAT were 74·1 and 74·5 Gy, respectively. The average prostate TCP were 0·956 and 0·958 for the IMRT and VMAT plans, respectively. The average PDVF of the IMRT and VMAT plans were 0·970 and 0·983, respectively. Although both the IMRT and VMAT plans showed very similar prostate TCP, the dosimetric and radiobiological results of the VMAT technique were slightly better than IMRT.ConclusionThe calculated PDVF for the prostate IMRT and VMAT plans agreed well with other dosimetric and radiobiological parameters in this study. PDVF was verified as an alternative of evaluation parameter in the quality assurance of prostate treatment planning.
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Balderson M, Brown D, Johnson P, Kirkby C. Under conditions of large geometric miss, tumor control probability can be higher for static gantry intensity-modulated radiation therapy compared to volume-modulated arc therapy for prostate cancer. Med Dosim 2016; 41:180-5. [PMID: 27067229 DOI: 10.1016/j.meddos.2015.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 12/04/2015] [Accepted: 12/29/2015] [Indexed: 10/22/2022]
Abstract
The purpose of this work was to compare static gantry intensity-modulated radiation therapy (IMRT) with volume-modulated arc therapy (VMAT) in terms of tumor control probability (TCP) under scenarios involving large geometric misses, i.e., those beyond what are accounted for when margin expansion is determined. Using a planning approach typical for these treatments, a linear-quadratic-based model for TCP was used to compare mean TCP values for a population of patients who experiences a geometric miss (i.e., systematic and random shifts of the clinical target volume within the planning target dose distribution). A Monte Carlo approach was used to account for the different biological sensitivities of a population of patients. Interestingly, for errors consisting of coplanar systematic target volume offsets and three-dimensional random offsets, static gantry IMRT appears to offer an advantage over VMAT in that larger shift errors are tolerated for the same mean TCP. For example, under the conditions simulated, erroneous systematic shifts of 15mm directly between or directly into static gantry IMRT fields result in mean TCP values between 96% and 98%, whereas the same errors on VMAT plans result in mean TCP values between 45% and 74%. Random geometric shifts of the target volume were characterized using normal distributions in each Cartesian dimension. When the standard deviations were doubled from those values assumed in the derivation of the treatment margins, our model showed a 7% drop in mean TCP for the static gantry IMRT plans but a 20% drop in TCP for the VMAT plans. Although adding a margin for error to a clinical target volume is perhaps the best approach to account for expected geometric misses, this work suggests that static gantry IMRT may offer a treatment that is more tolerant to geometric miss errors than VMAT.
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Affiliation(s)
- Michael Balderson
- Medical Physics Department, Tom Baker Cancer Centre, Calgary, Alberta; Jack Ady Cancer Centre, Lethbridge, Alberta.
| | - Derek Brown
- Medical Physics Department, Tom Baker Cancer Centre, Calgary, Alberta; Jack Ady Cancer Centre, Lethbridge, Alberta
| | - Patricia Johnson
- Medical Physics Department, Tom Baker Cancer Centre, Calgary, Alberta; Jack Ady Cancer Centre, Lethbridge, Alberta
| | - Charles Kirkby
- Medical Physics Department, Tom Baker Cancer Centre, Calgary, Alberta; Jack Ady Cancer Centre, Lethbridge, Alberta
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Amaloo C, Nazareth DP, Kumaraswamy LK. Comparison of hybrid volumetric modulated arc therapy (VMAT) technique and double arc VMAT technique in the treatment of prostate cancer. Radiol Oncol 2015; 49:291-8. [PMID: 26401136 PMCID: PMC4577227 DOI: 10.1515/raon-2015-0018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 02/26/2015] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Volumetric modulated arc therapy (VMAT) has quickly become accepted as standard of care for the treatment of prostate cancer based on studies showing it is able to provide faster delivery with adequate target coverage and reduced monitor units while maintaining organ at risk (OAR) sparing. This study aims to demonstrate the potential to increase dose conformality with increased planner control and OAR sparing using a hybrid treatment technique compared to VMAT. METHODS Eleven patients having been previously treated for prostate cancer with VMAT techniques were replanned with a hybrid technique on Varian Treatment Planning System. Multiple static IMRT fields (2 to 3) were planned initially based on critical OAR to reduce dose but provide some planning treatment volume (PTV) coverage. This was used as a base dose plan to provide 30-35% coverage for a single arc VMAT plan. RESULTS The clinical VMAT plan was used as a control for the purposes of comparison. Average of all OAR sparing between the hybrid technique and VMAT showed the hybrid plan delivering less dose in almost all cases except for V80 of the bladder and maximum dose to right femoral head. PTV coverage was superior with the VMAT technique. Monitor unit differences varied, with the hybrid plan able to deliver fewer units 37% of the time, similar results 18% of the time, and higher units 45% of the time. On average, the hybrid plan delivered 10% more monitor units. CONCLUSIONS The hybrid plan can be delivered in a single gantry rotation combining aspects of VMAT with regions of dynamic intensity modulated radiation therapy (IMRT) within the treatment arc.
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Affiliation(s)
- Christopher Amaloo
- Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - Daryl P Nazareth
- Department of Radiation Medicine, Roswell Park Cancer Institute and Department of Biophysics and Physiology, University at Buffalo, Buffalo, USA
| | - Lalith K Kumaraswamy
- Department of Radiation Medicine and Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, USA
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Isa M, Rehman J, Afzal M, Chow J. Dosimetric dependence on the collimator angle in prostate volumetric modulated arc therapy. INTERNATIONAL JOURNAL OF CANCER THERAPY AND ONCOLOGY 2014. [DOI: 10.14319/ijcto.0204.19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Dzierma Y, Bell K, Palm J, Nuesken F, Licht N, Rübe C. mARC vs. IMRT radiotherapy of the prostate with flat and flattening-filter-free beam energies. Radiat Oncol 2014; 9:250. [PMID: 25424536 PMCID: PMC4272773 DOI: 10.1186/s13014-014-0250-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 11/04/2014] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND There as yet exists no systematic planning study investigating the novel mARC rotational radiotherapy technique, which is conceptually different from VMAT. We therefore present a planning study for prostate cancer, comparing mARC with IMRT treatment at the same linear accelerator equipped with flat and flattening-filter-free (FFF) photon energies. METHODS We retrospectively re-contoured and re-planned treatment plans for 10 consecutive prostate cancer patients. Plans were created for a Siemens Artiste linear accelerator with flat 6 MV and FFF 7 MV photons, using the Prowess Panther treatment planning system. mARC and IMRT plans were compared with each other considering indices for plan quality and dose to organs at risk. All plans were exported to the machine and irradiated while measuring scattered dose by thermoluminescent dosimeters placed on an anthropomorphic phantom. Treatment times were also measured and compared. RESULTS All plans were found acceptable for treatment. There was no marked preference for either technique or energy from the point of view of target coverage and dose to organs at risk. Scattered dose was significantly decreased by the use of FFF energies. While mARC and IMRT plans were of very similar overall quality, treatment time could be markedly decreased both by the use of mARC and FFF energy. CONCLUSIONS Highly conformal treatment plans could be created both by the use of flat 6 MV and FFF 7 MV energy, using IMRT or mARC. For all practical purposes, the FFF 7 MV energy and mARC plans are acceptable for treatment, a combination of both allowing a drastic reduction in treatment time from over 5 minutes to about half this value.
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Affiliation(s)
- Yvonne Dzierma
- Department of Radiotherapy, Saarland University Medical Center, Kirrberger Str. Geb. 6.5, 66421, Homburg, Germany.
| | - Katharina Bell
- Department of Radiotherapy, Saarland University Medical Center, Kirrberger Str. Geb. 6.5, 66421, Homburg, Germany.
| | - Jan Palm
- Department of Radiotherapy, Saarland University Medical Center, Kirrberger Str. Geb. 6.5, 66421, Homburg, Germany.
| | - Frank Nuesken
- Department of Radiotherapy, Saarland University Medical Center, Kirrberger Str. Geb. 6.5, 66421, Homburg, Germany.
| | - Norbert Licht
- Department of Radiotherapy, Saarland University Medical Center, Kirrberger Str. Geb. 6.5, 66421, Homburg, Germany.
| | - Christian Rübe
- Department of Radiotherapy, Saarland University Medical Center, Kirrberger Str. Geb. 6.5, 66421, Homburg, Germany.
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Elith CA, Dempsey SE, Warren-Forward HM. Comparing four volumetric modulated arc therapy beam arrangements for the treatment of early-stage prostate cancer. J Med Radiat Sci 2014; 61:91-101. [PMID: 26229643 PMCID: PMC4175844 DOI: 10.1002/jmrs.52] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 04/03/2014] [Accepted: 04/04/2014] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION This study compared four different volumetric modulated arc therapy (VMAT) beam arrangements for the treatment of early-stage prostate cancer examining plan quality and the impact on a radiotherapy department's resources. METHODS Twenty prostate cases were retrospectively planned using four VMAT beam arrangements (1) a partial arc (PA), (2) one arc (1A), (3) one arc plus a partial arc (1A + PA) and (4) two arcs (2A). The quality of the dose distributions generated were compared by examining the overall plan quality, the homogeneity and conformity to the planning target volume (PTV), the number of monitor units and the dose delivered to the organs at risk. Departmental resources were considered by recording the planning time and beam delivery time. RESULTS Each technique produced a plan of similar quality that was considered adequate for treatment; though some differences were noted. The 1A, 1A + PA and 2A plans demonstrated a better conformity to the PTV which correlated to improved sparing of the rectum in the 60-70 Gy range for the 1A + PA and 2A techniques. The time needed to generate the plans was different for each technique ranging from 13.1 min for 1A + PA to 17.8 min for 1A. The PA beam delivery time was fastest with a mean time of 0.9 min. Beam-on times then increased with an increase in the number of arcs up to an average of 2.2 min for the 2A technique. CONCLUSION Which VMAT technique is best suited for clinical implementation for the treatment of prostate cancer may be dictated by the individual patient and the availability of departmental resources.
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Affiliation(s)
- Craig A Elith
- British Columbia Cancer Agency, Fraser Valley Centre Surrey, BC, Canada ; School of Health Sciences, University of Newcastle Callaghan, NSW, Australia
| | - Shane E Dempsey
- School of Health Sciences, University of Newcastle Callaghan, NSW, Australia
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Kim JI, Park JM, Park SY, Choi CH, Wu HG, Ye SJ. Assessment of potential jaw-tracking advantage using control point sequences of VMAT planning. J Appl Clin Med Phys 2014; 15:4625. [PMID: 24710450 PMCID: PMC5875480 DOI: 10.1120/jacmp.v15i2.4625] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Revised: 01/02/2014] [Accepted: 11/25/2013] [Indexed: 11/23/2022] Open
Abstract
This study aims to evaluate the potential jaw-tracking advantage using control point sequences of volume volumetric modulated arc therapy (VMAT) planning. VMAT plans for patients with prostate and head and neck (H&N) cancers were converted into new static arc (SA) plans. The SA plan consisted of a series of static fields at each control point of the VMAT plan. All other machine parameters of the SA plan were perfectly identical to those of the original VMAT plan. The jaw-tracking static arc (JTSA) plans were generated with fields that closed the jaws of each SA field into the multileaf collimators (MLCs) aperture. The dosimetric advantages of JTSA over SA were evaluated in terms of a dose-volume histogram (DVH) of organ at risk (OAR) after renormalizing both plans to make the same target coverage. Both plans were delivered to the MatriXX-based COMPASS system for 3D volume dose verification. The average jaw size reduction of the JTSA along the X direction was 3.1 ± 0.9 cm for prostate patients and 6.9 ± 1.9 cm for H&N patients. For prostate patients, the organs far from the target showed larger sparing (3.7%-8.1% on average) in JTSA than the organs adjacent to the target (1.1%-1.5%). For the H&N plans, the mean dose reductions for all organs ranged from 4.3% to 11.9%. The dose reductions were more significant in the dose regions of D80, D90, and D95 than the dose regions of D5, D10, and D20 for all patients. Likewise, the deliverability and reproducibility of jaw-tracking plan were validated. The measured dosimetric advantage of JTSA over SA coincided with the calculated one above.
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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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White P, Yee CK, Shan LC, Chung LW, Man NH, Cheung YS. A comparison of two systems of patient immobilization for prostate radiotherapy. Radiat Oncol 2014; 9:29. [PMID: 24447702 PMCID: PMC3905910 DOI: 10.1186/1748-717x-9-29] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 01/17/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Reproducibility of different immobilization systems, which may affect set-up errors, remains uncertain. Immobilization systems and their corresponding set-up errors influence the clinical target volume to planning target volume (CTV-PTV) margins and thus may result in undesirable treatment outcomes. This study compared the reproducibility of patient positioning with Hipfix system and whole body alpha cradle with respect to localized prostate cancer and investigated the existing CTV-PTV margins in the clinical oncology departments of two hospitals. METHODS Forty sets of data of patients with localized T1-T3 prostate cancer were randomly selected from two regional hospitals, with 20 patients immobilized by a whole-body alpha cradle system and 20 by a thermoplastic Hipfix system. Seven sets of the anterior-posterior (AP), cranial-caudal (CC) and medial-lateral (ML) deviations were collected from each patient. The reproducibility of patient positioning within the two hospitals was compared using a total vector error (TVE) parameter. In addition, CTV-PTV margins were computed using van Herk's formula. The resulting values were compared to the current CTV-PTV margins in both hospitals. RESULTS The TVE values were 5.1 and 2.8 mm for the Hipfix and the whole-body alpha cradle systems respectively. TVE associated with the whole-body alpha cradle system was found to be significantly less than the Hipfix system (p < 0.05). The CC axis in the Hipfix system attained the highest frequency of large (23.6%) and serious (7.9%) set-up errors. The calculated CTV to PTV margin was 8.3, 1.9 and 2.3 mm for the Hipfix system, and 2.1, 3.4 and 1.8 mm for the whole body alpha cradle in CC, ML and AP axes respectively. All but one (CC axis using Hipfix) margin calculated did not exceed the corresponding hospital protocol. The whole body alpha cradle system was found to be significantly better than the Hipfix system in terms of reproducibility (p < 0.05), especially in the CC axis. CONCLUSIONS The whole body alpha cradle system was more reproducible than the Hipfix system. In particular, the difference in CC axis contributed most to the results and the current CC margin for the Hipfix system might be considered as inadequate.
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Affiliation(s)
- Peter White
- The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Chui Ka Yee
- The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Lee Chi Shan
- The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Lee Wai Chung
- The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Ng Ho Man
- The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Yik Shing Cheung
- The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
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Dong P, Nguyen D, Ruan D, King C, Long T, Romeijn E, Low DA, Kupelian P, Steinberg M, Yang Y, Sheng K. Feasibility of prostate robotic radiation therapy on conventional C-arm linacs. Pract Radiat Oncol 2013; 4:254-60. [PMID: 25012834 DOI: 10.1016/j.prro.2013.10.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 10/29/2013] [Accepted: 10/30/2013] [Indexed: 11/25/2022]
Abstract
PURPOSE Significant dosimetric improvement for radiation therapy using optimized noncoplanar fields has been previously demonstrated. The purpose here is to study the feasibility of optimized robotic noncoplanar radiation therapy, termed 4π therapy, for prostate cancer treatments on a conventional C-arm linac. METHODS AND MATERIALS Twelve low-risk prostate cancer patients previously treated by 2-arc volumetric modulated arc therapy (VMAT) were selected. Forty gray in 5 fractions were prescribed to cover 95% of the prostate planning target volume (PTV). To replan by 4π therapy, a column generation method was used to optimize beam orientations and fluence. A total of 30 beams were selected for each patient. RESULTS Both planning methods provided adequate PTV coverage. Compared against VMAT plans, the 4π plan reduced the rectum V50%, V80%, V90%, D1cc, and the penile bulb maximum doses by 50%, 28%, 19% 11%, and 9% (P < .005), respectively, and the mean body dose was reduced from 2.07 Gy to 1.75 Gy (P = .0001). The bladder dose was only slightly reduced. CONCLUSIONS By optimizing beam angles and fluences in the noncoplanar solution space, superior prostate treatment plan quality was achieved compared against state of the art VMAT plans. The dosimetric potential for 4π therapy is established on an existing C-arm linac platform.
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Affiliation(s)
- Peng Dong
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Dan Nguyen
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Dan Ruan
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Christopher King
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Troy Long
- Department of Industrial and Operations, University of Michigan, Ann Arbor, Michigan
| | - Edwin Romeijn
- Department of Industrial and Operations, University of Michigan, Ann Arbor, Michigan
| | - Daniel A Low
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Patrick Kupelian
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Michael Steinberg
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Yingli Yang
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Ke Sheng
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California.
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Crowe SB, Kairn T, Middlebrook N, Hill B, Christie DRH, Knight RT, Kenny J, Langton CM, Trapp JV. Retrospective evaluation of dosimetric quality for prostate carcinomas treated with 3D conformal, intensity modulated and volumetric modulated arc radiotherapy. J Med Radiat Sci 2013; 60:131-8. [PMID: 26229621 PMCID: PMC4175818 DOI: 10.1002/jmrs.24] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 09/25/2013] [Accepted: 09/27/2013] [Indexed: 12/25/2022] Open
Abstract
INTRODUCTION This study examines and compares the dosimetric quality of radiotherapy treatment plans for prostate carcinoma across a cohort of 163 patients treated across five centres: 83 treated with three-dimensional conformal radiotherapy (3DCRT), 33 treated with intensity modulated radiotherapy (IMRT) and 47 treated with volumetric modulated arc therapy (VMAT). METHODS Treatment plan quality was evaluated in terms of target dose homogeneity and organs at risk (OAR), through the use of a set of dose metrics. These included the mean, maximum and minimum doses; the homogeneity and conformity indices for the target volumes; and a selection of dose coverage values that were relevant to each OAR. Statistical significance was evaluated using two-tailed Welch's T-tests. The Monte Carlo DICOM ToolKit software was adapted to permit the evaluation of dose metrics from DICOM data exported from a commercial radiotherapy treatment planning system. RESULTS The 3DCRT treatment plans offered greater planning target volume dose homogeneity than the other two treatment modalities. The IMRT and VMAT plans offered greater dose reduction in the OAR: with increased compliance with recommended OAR dose constraints, compared to conventional 3DCRT treatments. When compared to each other, IMRT and VMAT did not provide significantly different treatment plan quality for like-sized tumour volumes. CONCLUSIONS This study indicates that IMRT and VMAT have provided similar dosimetric quality, which is superior to the dosimetric quality achieved with 3DCRT.
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Affiliation(s)
- Scott B Crowe
- Science and Engineering Faculty, Queensland University of Technology Brisbane, Queensland, Australia
| | - Tanya Kairn
- Science and Engineering Faculty, Queensland University of Technology Brisbane, Queensland, Australia ; Premion, Wesley Medical Centre Brisbane, Queensland, Australia
| | | | - Brendan Hill
- Premion, Wesley Medical Centre Brisbane, Queensland, Australia
| | | | | | - John Kenny
- Australian Clinical Dosimetry Services, Australian Radiation Protection and Nuclear Safety Agency Melbourne, Victoria, Australia
| | - Christian M Langton
- Science and Engineering Faculty, Queensland University of Technology Brisbane, Queensland, Australia
| | - Jamie V Trapp
- Science and Engineering Faculty, Queensland University of Technology Brisbane, Queensland, Australia
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Elith CA, Dempsey SE, Warren-Forward HM. A retrospective planning analysis comparing intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) using two optimization algorithms for the treatment of early-stage prostate cancer. J Med Radiat Sci 2013; 60:84-92. [PMID: 26229615 PMCID: PMC4175809 DOI: 10.1002/jmrs.22] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 07/20/2013] [Accepted: 07/22/2013] [Indexed: 01/21/2023] Open
Abstract
INTRODUCTION The primary aim of this study is to compare intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) for the radical treatment of prostate cancer using version 10.0 (v10.0) of Varian Medical Systems, RapidArc radiation oncology system. Particular focus was placed on plan quality and the implications on departmental resources. The secondary objective was to compare the results in v10.0 to the preceding version 8.6 (v8.6). METHODS Twenty prostate cancer cases were retrospectively planned using v10.0 of Varian's Eclipse and RapidArc software. Three planning techniques were performed: a 5-field IMRT, VMAT using one arc (VMAT-1A), and VMAT with two arcs (VMAT-2A). Plan quality was assessed by examining homogeneity, conformity, the number of monitor units (MUs) utilized, and dose to the organs at risk (OAR). Resource implications were assessed by examining planning and treatment times. The results obtained using v10.0 were also compared to those previously reported by our group for v8.6. RESULTS In v10.0, each technique was able to produce a dose distribution that achieved the departmental planning guidelines. The IMRT plans were produced faster than VMAT plans and displayed improved homogeneity. The VMAT plans provided better conformity to the target volume, improved dose to the OAR, and required fewer MUs. Treatments using VMAT-1A were significantly faster than both IMRT and VMAT-2A. Comparison between versions 8.6 and 10.0 revealed that in the newer version, VMAT planning was significantly faster and the quality of the VMAT dose distributions produced were of a better quality. CONCLUSION VMAT (v10.0) using one or two arcs provides an acceptable alternative to IMRT for the treatment of prostate cancer. VMAT-1A has the greatest impact on reducing treatment time.
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Affiliation(s)
- Craig A Elith
- British Columbia Cancer Agency, Fraser Valley Centre Surrey, BC, Canada ; School of Health Sciences, University of Newcastle Newcastle, NSW, Australia
| | - Shane E Dempsey
- School of Health Sciences, University of Newcastle Newcastle, NSW, Australia
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Ishii K, Ogino R, Okada W, Nakahara R, Kawamorita R, Nakajima T. A dosimetric comparison of RapidArc and IMRT with hypofractionated simultaneous integrated boost to the prostate for treatment of prostate cancer. Br J Radiol 2013; 86:20130199. [PMID: 23995872 DOI: 10.1259/bjr.20130199] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To compare the dosimetric results and treatment delivery efficiency among RapidArc® (Varian Medical Systems, Palo Alto, CA), 7-field intensity-modulated radiotherapy (7-f IMRT) and 9-field IMRT (9-f IMRT) with hypofractionated simultaneous integrated boost to the prostate. METHODS RapidArc, 7-f IMRT and 9-f IMRT plans were created for 21 consecutive patients treated for high-risk prostate cancer using the Eclipse™ treatment planning system (Varian Medical Systems). All plans were designed to deliver 70.0 Gy in 28 fractions to the prostate planning target volume (PTV) while simultaneously delivering 50.4 Gy in 28 fractions to the pelvic nodal PTV. Target coverage and sparing of organs at risk (OARs) were compared across techniques. The total number of monitor units (MUs) and the treatment time were used to assess treatment delivery efficiency. RESULTS RapidArc resulted in slightly superior conformity and homogeneity of prostate PTV, whereas all plans were comparable with respect to dose to the nodal PTV. Although OARs sparing for RapidArc and 7-f IMRT plans were almost equivalent, 9-f IMRT achieved better sparing of the rectum and bladder than RapidArc and 7-f IMRT. RapidArc provided the highest treatment delivery efficiency with the lowest MUs and shortest treatment time. CONCLUSION RapidArc resulted in similar OAR sparing to 7-f IMRT, whereas 9-f IMRT provided the best OAR sparing. Treatment delivery efficiency is significantly higher for RapidArc. ADVANCES IN KNOWLEDGE This study validated the feasibility and limitations of RapidArc in the treatment of high-risk prostate cancer with complex pelvic target volumes.
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Affiliation(s)
- K Ishii
- Department of Radiation Oncology, Tane General Hospital, Osaka, Japan.
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Chow JCL, Jiang R. Comparison of dosimetric variation between prostate IMRT and VMAT due to patient's weight loss: Patient and phantom study. Rep Pract Oncol Radiother 2013; 18:272-8. [PMID: 24416564 DOI: 10.1016/j.rpor.2013.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 03/08/2013] [Accepted: 05/25/2013] [Indexed: 01/08/2023] Open
Abstract
AIM This study compared the dosimetric impact between prostate IMRT and VMAT due to patient's weight loss. BACKGROUND Dosimetric variation due to change of patient's body contour is difficult to predict in prostate IMRT and VMAT, since a large number of small and irregular segmental fields is used in the delivery. MATERIALS AND METHODS Five patients with prostate volumes ranging from 32.0 to 86.5 cm(3) and a heterogeneous pelvis phantom were used for prostate IMRT and VMAT plans using the same set of dose-volume constraints. Doses in IMRT and VMAT plans were recalculated with the patient's and phantom's body contour reduced by 0.5-2 cm to mimic size reduction. Dose coverage/criteria of the PTV and CTV and critical organs (rectum, bladder and femoral heads) were compared between IMRT and VMAT. RESULTS In IMRT plans, increases of the D99% for the PTV and CTV were equal to 4.0 ± 0.1% per cm of reduced depth, which were higher than those in VMAT plans (2.7 ± 0.24% per cm). Moreover, increases of the D30% of the rectum and bladder per reduced depth in IMRT plans (4.0 ± 0.2% per cm and 3.5 ± 0.5% per cm) were higher than those of VMAT (2.2 ± 0.2% per cm and 2.0 ± 0.6% per cm). This was also true for the increase of the D5% for the right femoral head in a patient or phantom with size reduction due to weight loss. CONCLUSIONS VMAT would be preferred to IMRT in prostate radiotherapy, when a patient has potential to suffer from weight loss during the treatment.
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Affiliation(s)
- James C L Chow
- Radiation Medicine Program, Princess Margaret Cancer Center, University Health Network, Toronto, ON, M5G 2M9, Canada ; Department of Radiation Oncology, University of Toronto, Toronto, ON, M5G 2M9, Canada
| | - Runqing Jiang
- Medical Physics Department, Grand River Regional Cancer Center, Kitchener, ON, N2G 1G3, Canada ; Department of Physics, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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Variation of PTV dose distribution on patient size in prostate VMAT and IMRT: a dosimetric evaluation using the PTV dose–volume factor. JOURNAL OF RADIOTHERAPY IN PRACTICE 2013. [DOI: 10.1017/s1460396913000137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractBackgroundWe propose to use the PTV dose–volume factor (PDVF) to evaluate treatment plans of prostate volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT).PurposePDVF was used to compare the variation of planning target volume (PTV) coverage between VMAT and IMRT because of weight loss of patient.Materials and methodsVMAT and IMRT plans of five patients (prostate volume = 32–86·5 cm3) using the 6 MV photon beams were created with the external contour reduced by depths of 0·5–2 cm to reflect the weight loss. Moreover, integral doses (volume integral of the patient dose) and prostate tumour control probability (TCP) were calculated.ResultsWe found that reduced depth resulted in PDVF decreasing 0·03 ± 4·7 × 10−4 (VMAT) and 0·04 ± 9·7 × 10−3 (IMRT) per cm for patients. The decrease of PDVF or degradation of PTV coverage was found more significant in IMRT plans than VMAT with patient size reduction. The integral dose did not change significantly between VMAT and IMRT, while the prostate TCP increased with an increase of reduced depth.ConclusionWe concluded that PDVF can be successfully used to evaluate the variation of PTV coverage because of weight loss of patient in prostate VMAT and IMRT. Degradation of PTV coverage in prostate VMAT is less significant than IMRT regarding patient size reduction.
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Chow JCL, Jiang R. Prostate volumetric-modulated arc therapy: dosimetry and radiobiological model variation between the single-arc and double-arc technique. J Appl Clin Med Phys 2013; 14:4053. [PMID: 23652240 PMCID: PMC5714414 DOI: 10.1120/jacmp.v14i3.4053] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 09/25/2012] [Accepted: 12/05/2012] [Indexed: 11/23/2022] Open
Abstract
This study investigates the dosimetry and radiobiological model variation when a second photon arc was added to prostate volumetric‐modulated arc therapy (VMAT) using the single‐arc technique. Dosimetry and radiobiological model comparison between the single‐arc and double‐arc prostate VMAT plans were performed on five patients with prostate volumes ranging from 29−68.1 cm3. The prescription dose was 78 Gy/39 fractions and the photon beam energy was 6 MV. Dose‐volume histogram, mean and maximum dose of targets (planning and clinical target volume) and normal tissues (rectum, bladder and femoral heads), dose‐volume criteria in the treatment plan (D99% of PTV; D30%,D50%,V17Gy and V35Gy of rectum and bladder; D5% of femoral heads), and dose profiles along the vertical and horizontal axis crossing the isocenter were determined using the single‐arc and double‐arc VMAT technique. For comparison, the monitor unit based on the RapidArc delivery method, prostate tumor control probability (TCP), and rectal normal tissue complication probability (NTCP) based on the Lyman‐Burman‐Kutcher algorithm were calculated. It was found that though the double‐arc technique required almost double the treatment time than the single‐arc, the double‐arc plan provided a better rectal and bladder dose‐volume criteria by shifting the delivered dose in the patient from the anterior–posterior direction to the lateral. As the femoral head was less radiosensitive than the rectum and bladder, the double‐arc technique resulted in a prostate VMAT plan with better prostate coverage and rectal dose‐volume criteria compared to the single‐arc. The prostate TCP of the double‐arc plan was found slightly increased (0.16%) compared to the single‐arc. Therefore, when the rectal dose‐volume criteria are very difficult to achieve in a single‐arc prostate VMAT plan, it is worthwhile to consider the double‐arc technique. PACS number: 87.55.D‐, 87.55.dk, 87.55.K‐, 87.55.Qr
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Affiliation(s)
- James C L Chow
- Radiation Medicine Program, Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada .
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Fenoglietto P, Servagi-Vernat S, Azria D, Giraud P. [Is volumetric modulated arctherapy the final evolution of conformal radiotherapy?]. Cancer Radiother 2012; 16:398-403. [PMID: 22925492 DOI: 10.1016/j.canrad.2012.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 05/22/2012] [Indexed: 10/28/2022]
Abstract
Technology development in radiotherapy has improved significantly during the last decade. The rapid evolution of 3D radiotherapy to intensity-modulated radiotherapy was possible thanks to inverse planning systems. Intensity modulated radiotherapy improved in its turn by possibilities of volumetric irradiation during a single rotation, reducing therefore the overall treatment. This article presents the technical parameters of this volumetric irradiation technique and a review of miscellaneous clinical indications.
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Affiliation(s)
- P Fenoglietto
- Département de cancérologie radiothérapie, CRLC Val d'Aurelle-Paul-Lamarque, Montpellier, France.
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Nguyen BT, Hornby C, Kron T, Cramb J, Rolfo A, Pham D, Haworth A, Tai KH, Foroudi F. Optimising the dosimetric quality and efficiency of post-prostatectomy radiotherapy: a planning study comparing the performance of volumetric-modulated arc therapy (VMAT) with an optimised seven-field intensity-modulated radiotherapy (IMRT) technique. J Med Imaging Radiat Oncol 2012; 56:211-9. [PMID: 22498196 DOI: 10.1111/j.1754-9485.2011.02324.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE The purpose of this study was to compare and evaluate radiotherapy treatment plans using volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT) for post-prostatectomy radiotherapy. METHODS AND MATERIALS The quality of radiotherapy plans for 10 patients planned and treated with a seven-field IMRT technique for biochemical failure post-prostatectomy were subsequently compared with 10 prospectively planned single-arc VMAT plans using the same computed tomography data set and treatment planning software. Plans were analysed using parameters to assess for target volume coverage, dose to organs at risk (OAR), biological outcomes, dose conformity and homogeneity, as well as the total monitor units (MU), planning and treatment efficiency. RESULTS The mean results for the study population are reported for the purpose of comparison. For IMRT, the median dose to the planning target volume, V(95%) and D(95%) was 71.1 Gy, 98.9% and 68.3 Gy compared with 71.2 Gy, 99.2% and 68.6 Gy for VMAT. There was no significant difference in the conformity index or homogeneity index. The VMAT plans achieved better sparing of the rectum and the left and right femora with a reduction in the median dose by 7.9, 6.3 and 3.6 Gy, respectively. The total number of monitor units (MU) was reduced by 24% and treatment delivery time by an estimated 3 min per fraction without a significant increase in planning requirements. CONCLUSIONS VMAT can achieve post-prostatectomy radiotherapy plans of comparable quality to IMRT with the potential to reduce dose to OAR and improve the efficiency of treatment delivery.
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Affiliation(s)
- Brandon T Nguyen
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Locked Bag 1, A’Beckett Street, Vic. 8006, Australia.
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Foroudi F, Wilson L, Bressel M, Haworth A, Hornby C, Pham D, Cramb J, Gill S, Tai KH, Kron T. A dosimetric comparison of 3D conformal vs intensity modulated vs volumetric arc radiation therapy for muscle invasive bladder cancer. Radiat Oncol 2012; 7:111. [PMID: 22824133 PMCID: PMC3444363 DOI: 10.1186/1748-717x-7-111] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 07/03/2012] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND To compare 3 Dimensional Conformal radiotherapy (3D-CRT) with Intensity Modulated Radiotherapy (IMRT) with Volumetric-Modulated Arc Therapy (VMAT) for bladder cancer. METHODS Radiotherapy plans for 15 patients with T2-T4N0M0 bladder cancer were prospectively developed for 3-DCRT, IMRT and VMAT using Varian Eclipse planning system. The same radiation therapist carried out all planning and the same clinical dosimetric constraints were used. 10 of the patients with well localised tumours had a simultaneous infield boost (SIB) of the primary tumour planned for both IMRT and VMAT. Tumour control probabilities and normal tissue complication probabilities were calculated. RESULTS Mean planning time for 3D-CRT, IMRT and VMAT was 30.0, 49.3, and 141.0 minutes respectively. The mean PTV conformity (CI) index for 3D-CRT was 1.32, for IMRT 1.05, and for VMAT 1.05. The PTV Homogeneity (HI) index was 0.080 for 3D-CRT, 0.073 for IMRT and 0.086 for VMAT. Tumour control and normal tissue complication probabilities were similar for 3D-CRT, IMRT and VMAT. The mean monitor units were 267 (range 250-293) for 3D-CRT; 824 (range 641-1083) for IMRT; and 403 (range 333-489) for VMAT (P < 0.05). Average treatment delivery time were 2:25min (range 2:01-3:09) for 3D-CRT; 4:39 (range 3:41-6:40) for IMRT; and 1:14 (range 1:13-1:14) for VMAT. In selected patients, the SIB did not result in a higher dose to small bowel or rectum. CONCLUSIONS VMAT is associated with similar dosimetric advantages as IMRT over 3D-CRT for muscle invasive bladder cancer. VMAT is associated with faster delivery times and less number of mean monitor units than IMRT. SIB is feasible in selected patients with localized tumours.
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Affiliation(s)
- Farshad Foroudi
- Division of Radiation Oncology, Peter MacCallum Cancer Center, Peter MacCallum Cancer Institute, St Andrews Place, East Melbourne, VIC, 3002, Australia
| | - Lesley Wilson
- Radiation Therapy Services, Peter MacCallum Cancer Center, Melbourne, VIC, Australia
| | - Mathias Bressel
- Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Annette Haworth
- Physical Sciences, Peter MacCallum Cancer Center, Melbourne, VIC, Australia
| | - Colin Hornby
- Radiation Therapy Services, Peter MacCallum Cancer Center, Melbourne, VIC, Australia
| | - Daniel Pham
- Radiation Therapy Services, Peter MacCallum Cancer Center, Melbourne, VIC, Australia
| | - Jim Cramb
- Physical Sciences, Peter MacCallum Cancer Center, Melbourne, VIC, Australia
| | - Suki Gill
- Division of Radiation Oncology, Peter MacCallum Cancer Center, Peter MacCallum Cancer Institute, St Andrews Place, East Melbourne, VIC, 3002, Australia
| | - Keen Hun Tai
- Division of Radiation Oncology, Peter MacCallum Cancer Center, Peter MacCallum Cancer Institute, St Andrews Place, East Melbourne, VIC, 3002, Australia
| | - Tomas Kron
- Physical Sciences, Peter MacCallum Cancer Center, Melbourne, VIC, Australia
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Chow JCL, Jiang R. Dosimetry estimation on variations of patient size in prostate volumetric-modulated arc therapy. Med Dosim 2012; 38:42-7. [PMID: 22819685 DOI: 10.1016/j.meddos.2012.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 04/17/2012] [Accepted: 05/08/2012] [Indexed: 01/12/2023]
Abstract
This study investigated the dosimetric variations of the target and critical organs of patients who had weight loss associated with prostate volumetric-modulated arc therapy (VMAT). Five patients with prostate volumes ranging from 32-86.5 cm³ were selected from a group of 30 patients. Prostate VMAT plans were carried out on each patient using the 6-MV photon beam with a single 360° arc. Decrease of patient size as a result of weight loss was mimicked by contracting the patient's external contour in the anterior, left, and right directions with depths from 0.5-2 cm. Soft tissue excluded by the contracted external contour was replaced by air and the dose distribution was recalculated using the same beam geometry and dose prescription. Dose-volume histograms and dose-volume points such as D99% and D5% for the planning target volume (PTV), clinical target volume (CTV), rectum, bladder, and femoral heads were calculated with variations of reduced depth. In addition, the minimum, maximum, and mean doses for the target and critical organs were determined. PTV and CTV D99% were found to have increased 2.86 ± 0.30% per cm and 2.75 ± 0.38% per cm of reduced depth ranging from 0.5-2 cm. Moreover, the rectal and bladder D30% increased 2.20 ± 0.20% per cm and 2.31 ± 0.83% per cm, and the femoral head D5% increased 3.30 ± 0.11% per cm of reduced depth. Results from variations of the minimum, maximum, and mean doses of the PTV, CTV, rectum, bladder, and femoral heads showed that there was a >5% increase of dose when the reduced depth reached 2 cm. This study provided dosimetry estimation for radiation oncology staff to justify dose variations of the target and critical organs when patients' weight loss occurred in prostate VMAT. Dose variations >5% were seen when the patients' reduced depth was equal to 2 cm.
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Affiliation(s)
- James C L Chow
- Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada.
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Risk-adaptive volumetric modulated arc therapy using biological objective functions for subvolume boosting in radiotherapy. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2012; 2012:348471. [PMID: 22792127 PMCID: PMC3390113 DOI: 10.1155/2012/348471] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 04/26/2012] [Indexed: 11/24/2022]
Abstract
Objectives. Simultaneous integrated boost (SIB) for prostate cancer allows increases in tumor control probability while respecting normal tissue dose constraints. Biological optimization functions that optimize based on treatment outcome can be used to create SIB prostate plans. This study investigates the feasibility of biologically optimized volumetric modulated arc therapy (VMAT) for SIB prostate radiotherapy. Methods. Five prostate cancer patients with diffusion-weighted MR images were selected for analysis. A two-step VMAT optimization was performed, which consisted of an initial biological optimization of a static gantry angle delivery followed by conversion of the static delivery to a single arc VMAT plan. A dosimetric analysis was performed on the resulting plans. Results. The VMAT plans resulted in a ΔEUD between the prostate and the boost volume of between 15.1 Gy and 20.3 Gy. Rectal volumes receiving 75.6 Gy ranged from 4.5 to 9.9%. Expected rectal normal tissue complication probabilities were between 8.6% and 21.4%. Maximum bladder doses ranged from 73.6 Gy to 75.8 Gy. Estimated treatment time was 120 s or less. Conclusions. The presented biological optimization method resulted in deliverable VMAT plans that achieved sufficient modulation for SIB without violating rectal and bladder dose constraints. Advances in knowledge. This study presents a method for creating simultaneous integrated boost VMAT treatments using biological outcome objective functions.
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Wong JHD, Fuduli I, Carolan M, Petasecca M, Lerch MLF, Perevertaylo VL, Metcalfe P, Rosenfeld AB. Characterization of a novel two dimensional diode array the “magic plate” as a radiation detector for radiation therapy treatment. Med Phys 2012; 39:2544-58. [DOI: 10.1118/1.3700234] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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