1
|
Treutwein M, Loeschel R, Hipp M, Koelbl O, Dobler B. Secondary malignancy risk for patients with localized prostate cancer after intensity-modulated radiotherapy with and without flattening filter. J Appl Clin Med Phys 2020; 21:197-205. [PMID: 33147377 PMCID: PMC7769399 DOI: 10.1002/acm2.13088] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 09/16/2020] [Accepted: 07/24/2020] [Indexed: 12/20/2022] Open
Abstract
Men treated for localized prostate cancer by radiotherapy have often a remaining life span of 10 yr or more. Therefore, the risk for secondary malignancies should be taken into account. Plans for ten patients were evaluated which had been performed on an Oncentra® treatment planning system for a treatment with an Elekta Synergy™ linac with Agility™ head. The investigated techniques involved IMRT and VMTA with and without flattening filter. Different dose response models were applied for secondary carcinoma and sarcoma risk in the treated region and also in the periphery. As organs at risk we regarded for carcinoma risk urinary bladder, rectum, colon, esophagus, thyroid, and for sarcoma risk bone and soft tissue. The excess absolute risk (EAR) was found very similar in the treated region for both techniques (IMRT and VMAT) and also for both with and without flattening filter. The secondary sarcoma risk resulted about one magnitude smaller than the secondary carcinoma risk. The EAR to the peripheral organs was statistically significant reduced by application of the flattening filter free mode concerning the flattening filter as main source of scattered dose. Application of flattening filter free mode can thus support to reduce second malignancy risk for patients with localized prostate cancer.
Collapse
Affiliation(s)
- Marius Treutwein
- Department for radiotherapy, Regensburg University Medical Center, Regensburg, Germany
| | - Rainer Loeschel
- Faculty of computer science and mathematics, Ostbayerische Technische Hochschule, Regensburg, Germany
| | - Matthias Hipp
- Department for radiotherapy, Regensburg University Medical Center, Regensburg, Germany.,Strahlentherapie, Klinikum St. Marien, Amberg, Germany
| | - Oliver Koelbl
- Department for radiotherapy, Regensburg University Medical Center, Regensburg, Germany
| | - Barbara Dobler
- Department for radiotherapy, Regensburg University Medical Center, Regensburg, Germany
| |
Collapse
|
2
|
Sasaki M, Ikushima H, Tsuzuki A, Sugimoto W. The effect of rectal gas on dose distribution during prostate cancer treatment using full arc and partial arc Volumetric Modulated Arc Therapy (VMAT) treatment plans. Rep Pract Oncol Radiother 2020; 25:974-980. [DOI: 10.1016/j.rpor.2020.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 08/10/2020] [Accepted: 09/21/2020] [Indexed: 11/25/2022] Open
|
3
|
Treutwein M, Hipp M, Koelbl O, Dobler B. Volumetric-modulated arc therapy and intensity-modulated radiation therapy treatment planning for prostate cancer with flattened beam and flattening filter free linear accelerators. J Appl Clin Med Phys 2017; 18:307-314. [PMID: 28857432 PMCID: PMC5875831 DOI: 10.1002/acm2.12168] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 07/17/2017] [Accepted: 07/20/2017] [Indexed: 12/25/2022] Open
Abstract
This study on patients with localized prostate cancer was set up to investigate valuable differences using flattened beam (FB) and flattening filter free (FFF) mode in the application of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT). For ten patients, four different plans were calculated with Oncentra planning system of Elekta, using Synergy machines: IMRT and VMAT, with and without flattening filter. Homogeneity and conformity indexes, dose to the organs at risk, and measurements of peripheral dose and dosimetric plan verification including record of the delivery times were analyzed and statistically evaluated. The indexes for homogeneity and conformity (CTV and PTV) are either advantageous or not significantly different for FFF compared to FB with one minor exception. Regarding the doses to the organs at risk and the measured peripheral dose, equivalent or lower doses were delivered for FFF than with FB. Furthermore, the delivery times were significantly shorter for FFF. VMAT compared to IMRT reveals benefits or at least equivalent values. VMAT-FFF combines the most advantageous plan quality parameters with the shortest delivery times and reduced peripheral dose and is therefore recommended for the given equipment and cancer localization.
Collapse
Affiliation(s)
- Marius Treutwein
- Department for Radiotherapy, Regensburg University Medical Center, Regensburg, Germany
| | - Matthias Hipp
- Department for Radiotherapy, Regensburg University Medical Center, Regensburg, Germany.,Klinikum St. Marien, Strahlentherapie, Amberg, Germany
| | - Oliver Koelbl
- Department for Radiotherapy, Regensburg University Medical Center, Regensburg, Germany
| | - Barbara Dobler
- Department for Radiotherapy, Regensburg University Medical Center, Regensburg, Germany
| |
Collapse
|
4
|
Pursley J, Damato AL, Czerminska MA, Margalit DN, Sher DJ, Tishler RB. A comparative study of standard intensity-modulated radiotherapy and RapidArc planning techniques for ipsilateral and bilateral head and neck irradiation. Med Dosim 2016; 42:31-36. [PMID: 27919621 DOI: 10.1016/j.meddos.2016.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 10/20/2016] [Accepted: 10/26/2016] [Indexed: 01/25/2023]
Abstract
The purpose of this study was to investigate class solutions using RapidArc volumetric-modulated arc therapy (VMAT) planning for ipsilateral and bilateral head and neck (H&N) irradiation, and to compare dosimetric results with intensity-modulated radiotherapy (IMRT) plans. A total of 14 patients who received ipsilateral and 10 patients who received bilateral head and neck irradiation were retrospectively replanned with several volumetric-modulated arc therapy techniques. For ipsilateral neck irradiation, the volumetric-modulated arc therapy techniques included two 360° arcs, two 360° arcs with avoidance sectors around the contralateral parotid, two 260° or 270° arcs, and two 210° arcs. For bilateral neck irradiation, the volumetric-modulated arc therapy techniques included two 360° arcs, two 360° arcs with avoidance sectors around the shoulders, and 3 arcs. All patients had a sliding-window-delivery intensity-modulated radiotherapy plan that was used as the benchmark for dosimetric comparison. For ipsilateral neck irradiation, a volumetric-modulated arc therapy technique using two 360° arcs with avoidance sectors around the contralateral parotid was dosimetrically comparable to intensity-modulated radiotherapy, with improved conformity (conformity index = 1.22 vs 1.36, p < 0.04) and lower contralateral parotid mean dose (5.6 vs 6.8Gy, p < 0.03). For bilateral neck irradiation, 3-arc volumetric-modulated arc therapy techniques were dosimetrically comparable to intensity-modulated radiotherapy while also avoiding irradiation through the shoulders. All volumetric-modulated arc therapy techniques required fewer monitor units than sliding-window intensity-modulated radiotherapy to deliver treatment, with an average reduction of 35% for ipsilateral plans and 67% for bilateral plans. Thus, for ipsilateral head and neck irradiation a volumetric-modulated arc therapy technique using two 360° arcs with avoidance sectors around the contralateral parotid is recommended. For bilateral neck irradiation, 2- or 3-arc techniques are dosimetrically comparable to intensity-modulated radiotherapy, but more work is needed to determine the optimal approaches by disease site.
Collapse
Affiliation(s)
- Jennifer Pursley
- Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women׳s Hospital, Boston, MA; Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA.
| | - Antonio L Damato
- Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women׳s Hospital, Boston, MA
| | - Maria A Czerminska
- Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women׳s Hospital, Boston, MA
| | - Danielle N Margalit
- Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women׳s Hospital, Boston, MA
| | - David J Sher
- Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women׳s Hospital, Boston, MA; Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX
| | - Roy B Tishler
- Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women׳s Hospital, Boston, MA
| |
Collapse
|
5
|
Chung JB, Kang SW, Eom KY, Song C, Choi KS, Suh TS. Comparison of Dosimetric Performance among Commercial Quality Assurance Systems for Verifying Pretreatment Plans of Stereotactic Body Radiotherapy Using Flattening-Filter-Free Beams. J Korean Med Sci 2016; 31:1742-1748. [PMID: 27709851 PMCID: PMC5056205 DOI: 10.3346/jkms.2016.31.11.1742] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 07/19/2016] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to compare the performance of different commercial quality assurance (QA) systems for the pretreatment verification plan of stereotactic body radiotherapy (SBRT) with volumetric arc therapy (VMAT) technique using a flattening-filter-free beam. The verification for 20 pretreatment cancer patients (seven lung, six spine, and seven prostate cancers) were tested using three QA systems (EBT3 film, I'mRT MatriXX array, and MapCHECK). All the SBRT-VMAT plans were optimized in the Eclipse (version 11.0.34) treatment planning system (TPS) using the Acuros XB dose calculation algorithm and were delivered to the Varian TrueBeam® accelerator equipped with a high-definition multileaf collimator. Gamma agreement evaluation was analyzed with the criteria of 2% dose difference and 2 mm distance to agreement (2%/2 mm) or 3%/3 mm. The highest passing rate (99.1% for 3%/3 mm) was observed on the MapCHECK system while the lowest passing rate was obtained on the film. The pretreatment verification results depend on the QA systems, treatment sites, and delivery beam energies. However, the delivery QA results for all QA systems based on the TPS calculation showed a good agreement of more than 90% for both the criteria. It is concluded that the three 2D QA systems have sufficient potential for pretreatment verification of the SBRT-VMAT plan.
Collapse
Affiliation(s)
- Jin Beom Chung
- Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Sang Won Kang
- Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Keun Yong Eom
- Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Changhoon Song
- Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Kyoung Sik Choi
- Department of Radiation Oncology, SAM Anyang Hospital, Anyang, Korea
| | - Tae Suk Suh
- Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Korea.
| |
Collapse
|
6
|
mARC Treatment of Hypopharynx Carcinoma with Flat and Flattening-Filter-Free Beam Energies - A Planning Study. PLoS One 2016; 11:e0164616. [PMID: 27741272 PMCID: PMC5065169 DOI: 10.1371/journal.pone.0164616] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 09/22/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The recently implemented mARC-rotation-technique is capable to deliver high dose rate bursts. For the case of hypopharynx cancer plans we evaluate whether the mARC can achieve an advantage in treatment time in comparison to IMRT. These plans consider two arcs with flat and flattening filter free (FFF) beam energies. MATERIALS AND METHODS For 8 hypopharynx-cancer patients step-and-shoot-IMRT and mARC plans were created retrospectively using flat and FFF beam energy. The comparison of the plan scenarios considered measures of quality for PTV coverage and sparing of organs at risk. All plans were irradiated on an anthromorphic phantom equipped with thermoluminescent dosimeters to measure scattered dose and treatment times. RESULTS A visual comparison of the dose distribution did not show a marked preference for either technique or energy. The statistical evaluation yielded significant differences in favor of the mARC technique and the FFF energy. Scattered dose could be decreased markedly by the use of the mARC technique. Treatment times could be reduced up to 3 minutes with the use of mARC in comparison to IMRT. The high dose rate energy results in another time advantage of about 1 minute. CONCLUSIONS All four plan scenarios yielded equally good quality plans. A combination of the mARC technique with FFF 7 MV high dose rate resulted in a decrease of treatment times from about 9 minutes to 5-6 minutes in comparison to 6 MV IMRT.
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Sales CP, Carvalho HDA, Taverna KC, Pastorello BF, Rubo RA, Borgonovi AF, Stuart SR, Rodrigues LN. Evaluation of different magnetic resonance imaging contrast materials to be used as dummy markers in image-guided brachytherapy for gynecologic malignancies. Radiol Bras 2016; 49:165-9. [PMID: 27403016 PMCID: PMC4938446 DOI: 10.1590/0100-3984.2015.0004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Objective To identify a contrast material that could be used as a dummy marker for
magnetic resonance imaging. Materials and Methods Magnetic resonance images were acquired with six different catheter-filling
materials-water, glucose 50%, saline, olive oil, glycerin, and copper
sulfate (CuSO4) water solution (2.08 g/L)-inserted into
compatible computed tomography/magnetic resonance imaging ring applicators
placed in a phantom made of gelatin and CuSO4. The best contrast
media were tested in four patients with the applicators in place. Results In T2-weighted sequences, the best contrast was achieved with the
CuSO4-filled catheters, followed by saline- and
glycerin-filled catheters, which presented poor visualization. In addition
(also in T2-weighted sequences), CuSO4 presented better contrast
when tested in the phantom than when tested in the patients, in which it
provided some contrast but with poor identification of the first dwell
position, mainly in the ring. Conclusion We found CuSO4 to be the best solution for visualization of the
applicator channels, mainly in T2-weighted images in vitro,
although the materials tested presented low signal intensity in the images
obtained in vivo, as well as poor precision in determining
the first dwell position.
Collapse
|
9
|
Berwouts D, Olteanu LAM, Speleers B, Duprez F, Madani I, Vercauteren T, De Neve W, De Gersem W. Intensity modulated arc therapy implementation in a three phase adaptive (18)F-FDG-PET voxel intensity-based planning strategy for head-and-neck cancer. Radiat Oncol 2016; 11:52. [PMID: 27039294 PMCID: PMC4818905 DOI: 10.1186/s13014-016-0629-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/28/2016] [Indexed: 12/15/2022] Open
Abstract
Background This study investigates the implementation of a new intensity modulated arc therapy (IMAT) class solution in comparison to a 6-static beam step-and-shoot intensity modulated radiotherapy (s-IMRT) for three-phase adaptive 18F-FDG-PET-voxel-based dose-painting-by-numbers (DPBN) for head-and-neck cancer. Methods We developed 18F-FDG-PET-voxel intensity-based IMAT employing multiple arcs and compared it to clinically used s-IMRT DPBN. Three IMAT plans using 18F-FDG-PET/CT acquired before treatment (phase I), after 8 fractions (phase II) and CT acquired after 18 fractions (phase III) were generated for each of 10 patients treated with 3 s-IMRT plans based on the same image sets. Based on deformable image registration (ABAS, version 0.41, Elekta CMS Software, Maryland Heights, MO), doses of the 3 plans were summed on the pretreatment CT using validated in-house developed software. Dosimetric indices in targets and organs-at-risk (OARs), biologic conformity of treatment plans set at ≤5 %, treatment quality and efficiency were compared between IMAT and s-IMRT for the whole group and for individual patients. Results Doses to most organs-at-risk (OARs) were significantly better in IMAT plans, while target levels were similar for both types of plans. On average, IMAT ipsilateral and contralateral parotid mean doses were 14.0 % (p = 0.001) and 12.7 % (p < 0.001) lower, respectively. Pharyngeal constrictors D50% levels were similar or reduced with up to 54.9 % for IMAT compared to s-IMRT for individual patient cases. IMAT significantly improved biologic conformity by 2.1 % for treatment phases I and II. 3D phantom measurements reported an agreement of ≥95 % for 3 % and 3 mm criteria for both treatment modalities. IMAT delivery time was significantly shortened on average by 41.1 %. Conclusions IMAT implementation significantly improved the biologic conformity as compared to s-IMRT in adaptive dose-escalated DPBN treatments. The better OAR sparing and faster delivery highly improved the treatment efficiency. Electronic supplementary material The online version of this article (doi:10.1186/s13014-016-0629-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Dieter Berwouts
- Department of Radiotherapy, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium. .,Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium.
| | - Luiza Ana Maria Olteanu
- Department of Radiotherapy, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium
| | | | - Frédéric Duprez
- Department of Radiotherapy, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium
| | - Indira Madani
- Ghent University, Ghent, Belgium.,Zürich University Hospital, Zürich, Switzerland
| | - Tom Vercauteren
- Department of Radiotherapy, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium
| | - Wilfried De Neve
- Department of Radiotherapy, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium.,Ghent University, Ghent, Belgium
| | | |
Collapse
|
10
|
Maerz M, Mittermair P, Krauss A, Koelbl O, Dobler B. Iterative metal artifact reduction improves dose calculation accuracy. Strahlenther Onkol 2016; 192:403-13. [DOI: 10.1007/s00066-016-0958-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 02/03/2016] [Indexed: 11/25/2022]
|
11
|
Lee J, Park JM, Wu HG, Kim JH, Ye SJ. The effect of body contouring on the dose distribution delivered with volumetric-modulated arc therapy technique. J Appl Clin Med Phys 2015; 16:365-375. [PMID: 26699591 PMCID: PMC5691003 DOI: 10.1120/jacmp.v16i6.5810] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 07/20/2015] [Accepted: 07/08/2015] [Indexed: 11/23/2022] Open
Abstract
The purpose of the study was to investigate the dosimetric effect defining the body structure with various Hounsfield unit (HU) threshold values on the dose distributions of volumetric‐modulated arc therapy (VMAT) plans. Twenty patients with prostate cancer and twenty patients with head and neck (H&N) cancer were retrospectively selected. For each patient, the body structure was redefined with HU threshold values of −180(Body180), −350(Body350), −700(Body700), and −980(Body980). For each patient, dose‐volumetric parameters with those body structures were calculated using identical VMAT plans. The differences in dose‐volumetric parameters due to the varied HU threshold values were calculated. For the prostate boost target volume, the maximum dose, mean dose, D95%, and D5% with Body180 were higher than those with Body980 by approximately 0.7% (p<0.001). For H&N target volumes, the changes in D95% of the targets receiving 67.5 Gy, 54 Gy, and 48 Gy between Body180 and Body980 were −1.2%, −0.9%, and −1.2%, respectively (p<0.001). The differences were larger for H&N VMAT plans than for prostate VMAT plans due to the inclusion of an immobilization device in the irradiated region in H&N cases. To apply all attenuating materials to dose calculation, the body structure would be defined with −980 HU. Otherwise, systematic error of about 1%, resulting in underdosage of the target volume, can occur. PACS number: 87.55.ne
Collapse
Affiliation(s)
- Jaegi Lee
- Seoul National University Graduate School of Convergence Science and Technology and Seoul National University Hospital.
| | | | | | | | | |
Collapse
|
12
|
Liu X, Yang Y, Jin F, He Y, Zhong M, Luo H, Qiu D, Li C, Yang H, He G, Wang Y. A comparison of volumetric modulated arc therapy and sliding-window intensity-modulated radiotherapy in the treatment of Stage I-II nasal natural killer/T-cell lymphoma. Med Dosim 2015; 41:42-6. [PMID: 26428072 DOI: 10.1016/j.meddos.2015.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 06/05/2015] [Accepted: 07/17/2015] [Indexed: 11/25/2022]
Abstract
This article is aimed to compare the dosimetric differences between volumetric modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) for Stage I-II nasal natural killer/T-cell lymphoma (NNKTL). Ten patients with Stage I-II NNKTL treated with IMRT were replanned with VMAT (2 arcs). The prescribed dose of the planning target volume (PTV) was 50Gy in 25 fractions. The VMAT plans with the Anisotropic Analytical Algorithm (Version 8.6.15) were based on an Eclipse treatment planning system; the monitor units (MUs) and treatment time (T) were scored to measure the expected treatment efficiency. All the 10 patients under the study were subject to comparisons regarding the quality of target coverage, the efficiency of delivery, and the exposure of normal adjacent organs at risk (OARs). The study shows that VMAT was associated with a better conformal index (CI) and homogeneity index (HI) (both p < 0.05) but slightly higher dose to OARs than IMRT. The MUs with VMAT (650.80 ± 24.59) were fewer than with IMRT (1300.10 ± 57.12) (relative reduction of 49.94%, p = 0.00) when using 2-Gy dose fractions. The treatment time with VMAT (3.20 ± 0.02 minutes) was shorter than with IMRT (7.38 ± 0.18 minutes) (relative reduction of 56.64%, p = 0.00). We found that VMAT and IMRT both provide satisfactory target dosimetric coverage and OARs sparing clinically. Likely to deliver a bit higher dose to OARs, VMAT in comparison with IMRT, is still a better choice for treatment of patients with Stage I-II NNKTL, thanks to better dose distribution, fewer MUs, and shorter delivery time.
Collapse
Affiliation(s)
- Xianfeng Liu
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China
| | - Yong Yang
- Department of Radiation Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China
| | - Fu Jin
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China
| | - Yanan He
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China
| | - Mingsong Zhong
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China
| | - Huanli Luo
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China
| | - Da Qiu
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China
| | - Chao Li
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China
| | - Han Yang
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China
| | - Guanglei He
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China
| | - Ying Wang
- Department of Radiation Oncology, Chongqing Cancer Institute, Chongqing, PR China.
| |
Collapse
|
13
|
Ali M, Babaiah M, Madhusudhan N, George G. Comparative dosimetric analysis of IMRT and VMAT (RapidArc) in brain, head and neck, breast and prostate malignancies. INTERNATIONAL JOURNAL OF CANCER THERAPY AND ONCOLOGY 2014. [DOI: 10.14319/ijcto.0301.9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
14
|
Jassal K, Sarkar B, Munshi A, Roy S. Consistency analysis for the performance of planar detector systems used in advanced radiotherapy. INTERNATIONAL JOURNAL OF CANCER THERAPY AND ONCOLOGY 2014. [DOI: 10.14319/ijcto.0301.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
15
|
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
|
16
|
Radiotherapy for unresectable sinonasal cancers: Dosimetric comparison of intensity modulated radiation therapy with coplanar and non-coplanar volumetric modulated arc therapy. Radiother Oncol 2014; 113:260-6. [DOI: 10.1016/j.radonc.2014.11.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 02/05/2023]
|
17
|
Influence of metallic dental implants and metal artefacts on dose calculation accuracy. Strahlenther Onkol 2014; 191:234-41. [DOI: 10.1007/s00066-014-0774-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 10/09/2014] [Indexed: 11/26/2022]
|
18
|
Craft D, Papp D, Unkelbach J. Plan averaging for multicriteria navigation of sliding window IMRT and VMAT. Med Phys 2014; 41:021709. [PMID: 24506600 DOI: 10.1118/1.4859295] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To describe a method for combining sliding window plans [intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT)] for use in treatment plan averaging, which is needed for Pareto surface navigation based multicriteria treatment planning. METHODS The authors show that by taking an appropriately defined average of leaf trajectories of sliding window plans, the authors obtain a sliding window plan whose fluence map is the exact average of the fluence maps corresponding to the initial plans. In the case of static-beam IMRT, this also implies that the dose distribution of the averaged plan is the exact dosimetric average of the initial plans. In VMAT delivery, the dose distribution of the averaged plan is a close approximation of the dosimetric average of the initial plans. RESULTS The authors demonstrate the method on three Pareto optimal VMAT plans created for a demanding paraspinal case, where the tumor surrounds the spinal cord. The results show that the leaf averaged plans yield dose distributions that approximate the dosimetric averages of the precomputed Pareto optimal plans well. CONCLUSIONS The proposed method enables the navigation of deliverable Pareto optimal plans directly, i.e., interactive multicriteria exploration of deliverable sliding window IMRT and VMAT plans, eliminating the need for a sequencing step after navigation and hence the dose degradation that is caused by such a sequencing step.
Collapse
Affiliation(s)
- David Craft
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Dávid Papp
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Jan Unkelbach
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| |
Collapse
|
19
|
Smet S, Lambrecht M, Vanstraelen B, Nuyts S. Clinical and dosimetric evaluation of RapidArc versus standard sliding window IMRT in the treatment of head and neck cancer. Strahlenther Onkol 2014; 191:43-50. [PMID: 25168752 DOI: 10.1007/s00066-014-0742-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 07/07/2014] [Indexed: 01/25/2023]
Abstract
BACKGROUND Several planning studies have already proven the substantial dosimetric advantages of RapidArc (RA) over standard intensity-modulated radiotherapy. We retrospectively compared RapidArc and standard sliding window IMRT (swIMRT) in locally advanced head and neck cancer, looking both at dosimetrics as well as toxicity and outcome. METHODS CT datasets of 78 patients treated with swIMRT and 79 patients treated with RA were included. To compare the resulting dose distributions, the dose-volume parameters were evaluated for the planning target volumes (PTVs), clinical target volumes (CTVs), and organs at risk (OARs), and the number of MU were calculated. Acute toxicity was assessed by the Common Toxicity Criteria version 3.0. RESULTS PTV coverage with the 95% isodose was slightly better for RA. Dose distribution has proven to be significantly more homogenous with RA and led to a reduction of 62% in MU with better OAR sparing. As for toxicity, more grade 3 mucositis and dysphagia was observed for swIMRT, though we observed more grade 3 dermatitis for RA. CONCLUSION In our retrospective analysis, RA had better target coverage and better sparing of the OAR. Overall, the grade of acute toxicity was lower for RA than for swIMRT for the same types of tumor locations, except for the grade of dermatitis.
Collapse
Affiliation(s)
- Stéphanie Smet
- Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium,
| | | | | | | |
Collapse
|
20
|
New possibilities for volumetric-modulated arc therapy using the AgilityTM 160-leaf multileaf collimator. Strahlenther Onkol 2014; 190:1066-74. [DOI: 10.1007/s00066-014-0692-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 05/14/2014] [Indexed: 10/25/2022]
|
21
|
Li Z, Zeng J, Wang Z, Zhu H, Wei Y. Dosimetric comparison of intensity modulated and volumetric arc radiation therapy for gastric cancer. Oncol Lett 2014; 8:1427-1434. [PMID: 25202345 PMCID: PMC4156206 DOI: 10.3892/ol.2014.2363] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 05/07/2014] [Indexed: 02/05/2023] Open
Abstract
The aim of the present study was to compare radiotherapy treatment plans for gastric cancer using intensity-modulated radiotherapy (IMRT) and single/double-arc volumetric modulated arc therapy (SA/DA-VMAT) delivery techniques. A total of 29 postoperative gastric cancer patients were enrolled in this study and each patient was scheduled 5-field IMRT (5F-IMRT), 7-field IMRT (7F-IMRT), SA-VMAT and DA-VMAT techniques. Dose-volume histogram statistics, conformal index (CI), homogeneity index (HI) and monitor units (MUs) were analyzed to compare treatment plans. The DA-VMAT plans exceeded the other three methods in terms of planning tumor volume dose and organs at risk in the kidneys, but not in the liver. DA-VMAT exhibited a better mean CI (0.87±0.03) and HI (0.10±0.01) than the other techniques. In addition, for the kidneys the dose sparing (V13, V18 and mean kidney dose) was improved by DA-VMAT plans. Similar results were observed for MUs. However, 5F-IMRT showed a marginal advantage in V30 and mean dose in normal liver when compared with DA-VMAT. The results of this study suggest that DA-VMAT provides improved tumor coverage when compared with 5F-IMRT, 7F-IMRT and SA-VMAT; however, DA-VMAT exhibits no advantage in liver protection when compared with 5F-IMRT. Further studies are required to establish differences in treatment outcomes among the four technologies.
Collapse
Affiliation(s)
- Zhiping Li
- Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Jianshuang Zeng
- Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Zi Wang
- Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Hong Zhu
- Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Yuquan Wei
- Department of Abdominal Oncology, Cancer Center of West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China ; State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| |
Collapse
|
22
|
Pyshniak V, Fotina I, Zverava A, Siamkouski S, Zayats E, Kopanitsa G, Okuntsau D. Efficiency of biological versus physical optimization for single-arc VMAT for prostate and head and neck cases. J Appl Clin Med Phys 2014; 15:4514. [PMID: 25207394 PMCID: PMC5875496 DOI: 10.1120/jacmp.v15i4.4514] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 02/12/2014] [Accepted: 02/11/2014] [Indexed: 12/02/2022] Open
Abstract
The aim of this work was to compare different approaches to VMAT optimization (biological vs. physical DVH-based) in two commercial treatment planning systems (TPS) for head and neck and prostate cases, using Pareto fronts. VMAT vs. IMRT Pareto front comparison was additionally performed in order to benchmark the optimizer efficiency and VMAT plan quality for each TPS. Three prostate and three head and neck cancer patients were selected for nine-beam IMRT and single-arc VMAT planning in Monaco 3.00 and Oncentra MasterPlan (OMP) 3.3 planning systems. Pareto fronts for prostate cases were constructed based on PTV coverage by 95% isodose and volume of rectum receiving 60 Gy or more. For head and neck cases, PTV coverage by the same isodose and mean dose to parotid gland were used for the construction of Pareto fronts. DVH analysis was performed together with evaluation of planning and delivery efficiency for all the plans. In the intersystem comparison for prostate plans, Monaco generated very similar IMRT and VMAT solutions. Quality of Monaco VMAT plans was superior compared to Oncentra in terms of conformity, homogeneity, and lower median dose to bladder due to biological formalism of optimization cost functions. For the head and neck cases, IMRT and VMAT plans were similar in both systems, except the case where a very strong modulation was required. In this situation single-arc VMAT plan generated with OMP was inferior compared to IMRT. VMAT OMP solutions were similar to Monaco or slightly better for two less-modulated head and neck cases. However, this advantage was achieved on the cost of lower conformity and homogeneity of the Oncentra VMAT plans. IMRT and VMAT solutions generated by Monaco were very similar for both prostate and head and neck cases. Oncentra system shows a bigger difference, and use of the dual-arc VMAT would be recommended to achieve the same plan quality as nine-field IMRT. Biological optimization seems beneficial in terms of plan conformity and homogeneity and allowed achieving lower OAR doses for prostate cases. In complex anatomical situations represented by head and neck cases, sequencing algorithm in Monaco imposed limitations on VMAT plan quality in the intersystem comparison.
Collapse
|
23
|
Chen H, Winey BA, Daartz J, Oh KS, Shin JH, Gierga DP. Efficiency gains for spinal radiosurgery using multicriteria optimization intensity modulated radiation therapy guided volumetric modulated arc therapy planning. Pract Radiat Oncol 2014; 5:49-55. [PMID: 25413420 DOI: 10.1016/j.prro.2014.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 04/16/2014] [Accepted: 04/17/2014] [Indexed: 11/18/2022]
Abstract
PURPOSE To evaluate plan quality and delivery efficiency gains of volumetric modulated arc therapy (VMAT) versus a multicriteria optimization-based intensity modulated radiation therapy (MCO-IMRT) for stereotactic radiosurgery of spinal metastases. METHODS AND MATERIALS MCO-IMRT plans (RayStation V2.5; RaySearch Laboratories, Stockholm, Sweden) of 10 spinal radiosurgery cases using 7-9 beams were developed for clinical delivery, and patients were replanned using VMAT with partial arcs. The prescribed dose was 18 Gy, and target coverage was maximized such that the maximum dose to the planning organ-at-risk volume (PRV) of the spinal cord was 10 or 12 Gy. Dose-volume histogram (DVH) constraints from the clinically acceptable MCO-IMRT plans were utilized for VMAT optimization. Plan quality and delivery efficiency with and without collimator rotation for MCO-IMRT and VMAT were compared and analyzed based upon DVH, planning target volume coverage, homogeneity index, conformity number, cord PRV sparing, total monitor units (MU), and delivery time. RESULTS The VMAT plans were capable of matching most DVH constraints from the MCO-IMRT plans. The ranges of MU were 4808-7193 for MCO-IMRT without collimator rotation, 3509-5907 for MCO-IMRT with collimator rotation, 4444-7309 for VMAT without collimator rotation, and 3277-5643 for VMAT with collimator of 90 degrees. The MU for the VMAT plans were similar to their corresponding MCO-IMRT plans, depending upon the complexity of the target and PRV geometries, but had a larger range. The delivery times of the MCO-IMRT and VMAT plans, both with collimator rotation, were 18.3 ± 2.5 minutes and 14.2 ± 2.0 minutes, respectively (P < .05). CONCLUSIONS The MCO-IMRT and VMAT can create clinically acceptable plans for spinal radiosurgery. The MU for MCO-IMRT and VMAT can be reduced significantly by utilizing a collimator rotation following the orientation of the spinal cord. Plan quality for VMAT is similar to MCO-IMRT, with similar MU for both modalities. Delivery times can be reduced by nominally 25% with VMAT.
Collapse
Affiliation(s)
- Huixiao Chen
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Brian A Winey
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Juliane Daartz
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Kevin S Oh
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - John H Shin
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - David P Gierga
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
| |
Collapse
|
24
|
Boylan C, Rowbottom C. A bias-free, automated planning tool for technique comparison in radiotherapy - application to nasopharyngeal carcinoma treatments. J Appl Clin Med Phys 2014; 15:4530. [PMID: 24423853 PMCID: PMC5711248 DOI: 10.1120/jacmp.v15i1.4530] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/25/2013] [Accepted: 07/17/2013] [Indexed: 12/01/2022] Open
Abstract
In this study a novel, user‐independent automated planning technique was developed to objectively compare volumetric‐modulated arc therapy (VMAT) and intensity‐modulated radiotherapy (IMRT) for nasopharyngeal carcinoma planning, and to determine which technique offers a greater benefit for parotid‐sparing and dose escalation strategies. Ten patients were investigated, with a standard prescription of three dose levels to the target volumes (70, 63, and 56 Gy), using a simultaneous integrated boost in 33 fractions. The automated tool was used to investigate three planning strategies with both IMRT and VMAT: clinically acceptable plan creation, parotid dose sparing, and dose escalation. Clinically acceptable plans were achieved for all patients using both techniques. For parotid‐sparing, automated planning reduced the mean dose to a greater extent using VMAT rather than IMRT (17.0 Gy and 19.6 Gy, respectively, p<0.01). For dose escalation to the mean of the main clinical target volume, neither VMAT nor IMRT offered a significant benefit over the other. The OAR‐limiting prescriptions for VMAT ranged from 84‐98 Gy, compared to 76‐110 Gy for IMRT. Employing a user‐independent planning technique, it was possible to objectively compare VMAT and IMRT for nasopharyngeal carcinoma treatment strategies. VMAT offers a parotid‐sparing improvement, but no significant benefit was observed for dose escalation to the primary target. PACS numbers: 87.55.D‐, 87.55.kd
Collapse
Affiliation(s)
- Christopher Boylan
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust.
| | | |
Collapse
|
25
|
Chen H, Craft DL, Gierga DP. Multicriteria optimization informed VMAT planning. Med Dosim 2013; 39:64-73. [PMID: 24360919 DOI: 10.1016/j.meddos.2013.10.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/18/2013] [Accepted: 10/21/2013] [Indexed: 11/19/2022]
Abstract
We developed a patient-specific volumetric-modulated arc therapy (VMAT) optimization procedure using dose-volume histogram (DVH) information from multicriteria optimization (MCO) of intensity-modulated radiotherapy (IMRT) plans. The study included 10 patients with prostate cancer undergoing standard fractionation treatment, 10 patients with prostate cancer undergoing hypofractionation treatment, and 5 patients with head/neck cancer. MCO-IMRT plans using 20 and 7 treatment fields were generated for each patient on the RayStation treatment planning system (clinical version 2.5, RaySearch Laboratories, Stockholm, Sweden). The resulting DVH of the 20-field MCO-IMRT plan for each patient was used as the reference DVH, and the extracted point values of the resulting DVH of the MCO-IMRT plan were used as objectives and constraints for VMAT optimization. Weights of objectives or constraints of VMAT optimization or both were further tuned to generate the best match with the reference DVH of the MCO-IMRT plan. The final optimal VMAT plan quality was evaluated by comparison with MCO-IMRT plans based on homogeneity index, conformity number of planning target volume, and organ at risk sparing. The influence of gantry spacing, arc number, and delivery time on VMAT plan quality for different tumor sites was also evaluated. The resulting VMAT plan quality essentially matched the 20-field MCO-IMRT plan but with a shorter delivery time and less monitor units. VMAT plan quality of head/neck cancer cases improved using dual arcs whereas prostate cases did not. VMAT plan quality was improved by fine gantry spacing of 2 for the head/neck cancer cases and the hypofractionation-treated prostate cancer cases but not for the standard fractionation-treated prostate cancer cases. MCO-informed VMAT optimization is a useful and valuable way to generate patient-specific optimal VMAT plans, though modification of the weights of objectives or constraints extracted from resulting DVH of MCO-IMRT or both is necessary.
Collapse
Affiliation(s)
- Huixiao Chen
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - David L Craft
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - David P Gierga
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
| |
Collapse
|
26
|
Cilla S, Deodato F, Digesù C, Macchia G, Picardi V, Ferro M, Sallustio G, De Spirito M, Piermattei A, Morganti AG. Assessing the feasibility of volumetric-modulated arc therapy using simultaneous integrated boost (SIB-VMAT): An analysis for complex head-neck, high-risk prostate and rectal cancer cases. Med Dosim 2013; 39:108-16. [PMID: 24342167 DOI: 10.1016/j.meddos.2013.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 10/02/2013] [Accepted: 11/11/2013] [Indexed: 10/25/2022]
Abstract
Intensity-modulated radiotherapy (IMRT) allowed the simultaneous delivery of different doses to different target volumes within a single fraction, an approach called simultaneous integrated boost (SIB). As consequence, the fraction dose to the boost volume can be increased while keeping low doses to the elective volumes, and the number of fractions and overall treatment time will be reduced, translating into better radiobiological effectiveness. In recent years, volumetric-modulated arc therapy (VMAT) has been shown to provide similar plan quality with respect to fixed-field IMRT but with large reduction in treatment time and monitor units (MUs) number. However, the feasibility of VMAT when used with SIB strategy has few investigations to date. We explored the potential of VMAT in a SIB strategy for complex cancer sites. A total of 15 patients were selected, including 5 head-and-neck, 5 high-risk prostate, and 5 rectal cancer cases. Both a double-arc VMAT and a 7-field IMRT plan were generated for each case using Oncentra MasterPlan treatment planning system for an Elekta Precise linac. Dosimetric indexes for targets and organs at risk (OARs) were compared based on dose-volume histograms. Conformity index, homogeneity index, and dose-contrast index were used for target analyses. The equivalent uniform doses and the normal tissue complication probabilities were calculated for main OARs. MUs number and treatment time were analyzed to score treatment efficiency. Pretreatment dosimetry was performed using 2-dimensional (2D)-array dosimeter. SIB-VMAT plans showed a high level of fluence modulation needed for SIB treatments, high conformal dose distribution, similar target coverage, and a tendency to improve OARs sparing compared with the benchmark SIB-IMRT plans. The median treatment times reduced from 13 to 20 minutes to approximately 5 minutes for all cases with SIB-VMAT, with a MUs reduction up to 22.5%. The 2D-array ion-chambers' measurements reported an agreement of more than 95% for a criterion of 3% to 3mm. SIB-VMAT was able to combine the advantages of conventional SIB-IMRT with its highly conformal dose distribution and OARs sparing and the advantages of 3D-conformal radiotherapy with its fast delivery.
Collapse
Affiliation(s)
- Savino Cilla
- Medical Physics Unit, Fondazione di ricerca e cura "Giovanni Paolo II," Università Cattolica del Sacro Cuore, Campobasso, Italy.
| | - Francesco Deodato
- Radiation Oncology Unit, Fondazione di ricerca e cura "Giovanni Paolo II," Università Cattolica del Sacro Cuore, Campobasso, Italy
| | - Cinzia Digesù
- Radiation Oncology Unit, Fondazione di ricerca e cura "Giovanni Paolo II," Università Cattolica del Sacro Cuore, Campobasso, Italy
| | - Gabriella Macchia
- Radiation Oncology Unit, Fondazione di ricerca e cura "Giovanni Paolo II," Università Cattolica del Sacro Cuore, Campobasso, Italy
| | - Vincenzo Picardi
- Radiation Oncology Unit, Fondazione di ricerca e cura "Giovanni Paolo II," Università Cattolica del Sacro Cuore, Campobasso, Italy
| | - Marica Ferro
- Radiation Oncology Unit, Fondazione di ricerca e cura "Giovanni Paolo II," Università Cattolica del Sacro Cuore, Campobasso, Italy
| | - Giuseppina Sallustio
- Radiology Unit, Fondazione di ricerca e cura "Giovanni Paolo II," Università Cattolica del Sacro Cuore, Campobasso, Italy
| | - Marco De Spirito
- Physics Institute, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Angelo Piermattei
- Physics Institute, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Alessio G Morganti
- Radiation Oncology Unit, Fondazione di ricerca e cura "Giovanni Paolo II," Università Cattolica del Sacro Cuore, Campobasso, Italy
| |
Collapse
|
27
|
Tanooka M, Doi H, Miura H, Inoue H, Niwa Y, Takada Y, Fujiwara M, Sakai T, Sakamoto K, Kamikonya N, Hirota S. Three-dimensional radiochromic film dosimetry for volumetric modulated arc therapy using a spiral water phantom. JOURNAL OF RADIATION RESEARCH 2013; 54:1153-1159. [PMID: 23685667 PMCID: PMC3823780 DOI: 10.1093/jrr/rrt059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Revised: 04/11/2013] [Accepted: 04/11/2013] [Indexed: 06/02/2023]
Abstract
We validated 3D radiochromic film dosimetry for volumetric modulated arc therapy (VMAT) using a newly developed spiral water phantom. The phantom consists of a main body and an insert box, each of which has an acrylic wall thickness of 3 mm and is filled with water. The insert box includes a spiral film box used for dose-distribution measurement, and a film holder for positioning a radiochromic film. The film holder has two parallel walls whose facing inner surfaces are equipped with spiral grooves in a mirrored configuration. The film is inserted into the spiral grooves by its side edges and runs along them to be positioned on a spiral plane. Dose calculation was performed by applying clinical VMAT plans to the spiral water phantom using a commercial Monte Carlo-based treatment-planning system, Monaco, whereas dose was measured by delivering the VMAT beams to the phantom. The calculated dose distributions were resampled on the spiral plane, and the dose distributions recorded on the film were scanned. Comparisons between the calculated and measured dose distributions yielded an average gamma-index pass rate of 87.0% (range, 91.2-84.6%) in nine prostate VMAT plans under 3 mm/3% criteria with a dose-calculation grid size of 2 mm. The pass rates were increased beyond 90% (average, 91.1%; range, 90.1-92.0%) when the dose-calculation grid size was decreased to 1 mm. We have confirmed that 3D radiochromic film dosimetry using the spiral water phantom is a simple and cost-effective approach to VMAT dose verification.
Collapse
Affiliation(s)
- Masao Tanooka
- Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Hiroshi Doi
- Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Hideharu Miura
- Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Hiroyuki Inoue
- Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Yasue Niwa
- Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Yasuhiro Takada
- Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Masayuki Fujiwara
- Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Toshiyuki Sakai
- Department of Radiological Technology, Hyogo College of Medicine College Hospital, Hyogo, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Kiyoshi Sakamoto
- Department of Radiological Technology, Hyogo College of Medicine College Hospital, Hyogo, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Norihiko Kamikonya
- Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| | - Shozo Hirota
- Department of Radiology, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya City, Hyogo, 663-8501, Japan
| |
Collapse
|
28
|
Ashamalla H, Tejwani A, Parameritis I, Swamy U, Luo PC, Guirguis A, Lavaf A. Comparison study of intensity modulated arc therapy using single or multiple arcs to intensity modulated radiation therapy for high-risk prostate cancer. Radiat Oncol J 2013; 31:104-10. [PMID: 23865007 PMCID: PMC3712173 DOI: 10.3857/roj.2013.31.2.104] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/06/2013] [Accepted: 06/10/2013] [Indexed: 12/25/2022] Open
Abstract
Purpose Intensity modulated arc therapy (IMAT) is a form of intensity modulated radiation therapy (IMRT) that delivers dose in single or multiple arcs. We compared IMRT plans versus single-arc field (1ARC) and multi-arc fields (3ARC) IMAT plans in high-risk prostate cancer. Materials and Methods Sixteen patients were studied. Prostate (PTVP), right pelvic (PTVRtLN) and left pelvic lymph nodes (PTVLtLN), and organs at risk were contoured. PTVP, PTVRtLN, and PTVLtLN received 50.40 Gy followed by a boost to PTVB of 28.80 Gy. Three plans were per patient generated: IMRT, 1ARC, and 3ARC. We recorded the dose to the PTV, the mean dose (DMEAN) to the organs at risk, and volume covered by the 50% isodose. Efficiency was evaluated by monitor units (MU) and beam on time (BOT). Conformity index (CI), Paddick gradient index, and homogeneity index (HI) were also calculated. Results Average Radiation Therapy Oncology Group CI was 1.17, 1.20, and 1.15 for IMRT, 1ARC, and 3ARC, respectively. The plans' HI were within 1% of each other. The DMEAN of bladder was within 2% of each other. The rectum DMEAN in IMRT plans was 10% lower dose than the arc plans (p < 0.0001). The GI of the 3ARC was superior to IMRT by 27.4% (p = 0.006). The average MU was highest in the IMRT plans (1686) versus 1ARC (575) versus 3ARC (1079). The average BOT was 6 minutes for IMRT compared to 1.3 and 2.9 for 1ARC and 3ARC IMAT (p < 0.05). Conclusion For high-risk prostate cancer, IMAT may offer a favorable dose gradient profile, conformity, MU and BOT compared to IMRT.
Collapse
Affiliation(s)
- Hani Ashamalla
- New York Methodist Hospital, Brooklyn, NY, USA. ; Leading Edge Radiation Oncology (LEROS), Weill Medical College of Cornell University, Brooklyn, NY, USA
| | | | | | | | | | | | | |
Collapse
|
29
|
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.
Collapse
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
| |
Collapse
|
30
|
Masi L, Doro R, Favuzza V, Cipressi S, Livi L. Impact of plan parameters on the dosimetric accuracy of volumetric modulated arc therapy. Med Phys 2013; 40:071718. [DOI: 10.1118/1.4810969] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
31
|
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.
Collapse
|
32
|
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
Collapse
Affiliation(s)
- James C L Chow
- Radiation Medicine Program, Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada .
| | | |
Collapse
|
33
|
Sanghangthum T, Suriyapee S, Srisatit S, Pawlicki T. Statistical process control analysis for patient-specific IMRT and VMAT QA. JOURNAL OF RADIATION RESEARCH 2013; 54:546-52. [PMID: 23220776 PMCID: PMC3650738 DOI: 10.1093/jrr/rrs112] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
This work applied statistical process control to establish the control limits of the % gamma pass of patient-specific intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) quality assurance (QA), and to evaluate the efficiency of the QA process by using the process capability index (Cpml). A total of 278 IMRT QA plans in nasopharyngeal carcinoma were measured with MapCHECK, while 159 VMAT QA plans were undertaken with ArcCHECK. Six megavolts with nine fields were used for the IMRT plan and 2.5 arcs were used to generate the VMAT plans. The gamma (3%/3 mm) criteria were used to evaluate the QA plans. The % gamma passes were plotted on a control chart. The first 50 data points were employed to calculate the control limits. The Cpml was calculated to evaluate the capability of the IMRT/VMAT QA process. The results showed higher systematic errors in IMRT QA than VMAT QA due to the more complicated setup used in IMRT QA. The variation of random errors was also larger in IMRT QA than VMAT QA because the VMAT plan has more continuity of dose distribution. The average % gamma pass was 93.7% ± 3.7% for IMRT and 96.7% ± 2.2% for VMAT. The Cpml value of IMRT QA was 1.60 and VMAT QA was 1.99, which implied that the VMAT QA process was more accurate than the IMRT QA process. Our lower control limit for % gamma pass of IMRT is 85.0%, while the limit for VMAT is 90%. Both the IMRT and VMAT QA processes are good quality because Cpml values are higher than 1.0.
Collapse
Affiliation(s)
- Taweap Sanghangthum
- Department of Nuclear Engineering, Faculty of Engineering, Chulalongkorn University, Thailand
- Division of Therapeutic Radiology and Oncology, Department of Radiology, King Chulalongkorn Memorial Hospital, Thailand
| | - Sivalee Suriyapee
- Division of Therapeutic Radiology and Oncology, Faculty of Medicine, Chulalongkorn University, Thailand
- Corresponding author. Tel: +662-256-4334; Fax: +662-256-4590; E-mail:
| | - Somyot Srisatit
- Department of Nuclear Engineering, Faculty of Engineering, Chulalongkorn University, Thailand
| | - Todd Pawlicki
- Department of Radiation Medicine and Applied Sciences, University of California, San Diego, USA
| |
Collapse
|
34
|
Inverse planned constant dose rate volumetric modulated arc therapy (VMAT) as an efficient alternative to five-field intensity modulated radiation therapy (IMRT) for prostate. JOURNAL OF RADIOTHERAPY IN PRACTICE 2013. [DOI: 10.1017/s1460396913000083] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractPurposeThe aim of this work was to determine if volumetric modulated arc therapy (VMAT) plans, created for constant dose-rate (cdrVMAT) delivery are a viable alternative to step and shoot five-field intensity modulated radiation therapy (IMRT).Materials and methodsThe cdrVMAT plans, inverse planned on a treatment planning system with no solution to account for couch top or rails, were created for delivery on a linear accelerator with no variable dose rate control system. A series of five-field IMRT and cdrVMAT plans were created using dual partial arcs (gantry rotating between 260° and 100°) with 4° control points for ten prostate patients with the average rectal constraint incrementally increased. Pareto fronts were compared for the planning target volume homogeneity and average rectal dose between the two techniques for each patient. Also investigated were tumour control probability and normal tissue complication probability values for each technique. The delivery parameters [monitor units (MU) and time] and delivery accuracy of the IMRT and VMAT plans were also compared.ResultsPareto fronts showed that the dual partial arc plans were superior to the five-field IMRT plans, particularly for the clinically acceptable plans where average rectal doses were less for rotational plans (p = 0·009) with no statistical difference in target homogeneity. The cdrVMAT plans had significantly more MU (p = 0·005) but the average delivery time was significantly less than the IMRT plans by 42%. All clinically acceptable cdrVMAT plans were accurate in their delivery (gamma 99·2 ± 1·1%, 3%3 mm criteria).ConclusionsAccurate delivery of dual partial arc cdrVMAT avoiding the couch top and rails has been demonstrated.
Collapse
|
35
|
Clinical experience transitioning from IMRT to VMAT for head and neck cancer. Med Dosim 2012; 38:171-5. [PMID: 23246253 DOI: 10.1016/j.meddos.2012.10.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 10/31/2012] [Accepted: 10/31/2012] [Indexed: 11/22/2022]
Abstract
To quantify clinical differences for volumetric modulated arc therapy (VMAT) versus intensity modulated radiation therapy (IMRT) in terms of dosimetric endpoints and planning and delivery time, twenty head and neck cancer patients have been considered for VMAT using Nucletron Oncentra MasterPlan delivered via an Elekta linear accelerator. Differences in planning time between IMRT and VMAT were estimated accounting for both optimization and calculation. The average delivery time per patient was obtained retrospectively using the record and verify software. For the dosimetric comparison, all contoured organs at risk (OARs) and planning target volumes (PTVs) were evaluated. Of the 20 cases considered, 14 had VMAT plans approved. Six VMAT plans were rejected due to unacceptable dose to OARs. In terms of optimization time, there was minimal difference between the two modalities. The dose calculation time was significantly longer for VMAT, 4 minutes per 358 degree arc versus 2 minutes for an entire IMRT plan. The overall delivery time was reduced by 9.2 ± 3.9 minutes for VMAT (51.4 ± 15.6%). For the dosimetric comparison of the 14 clinically acceptable plans, there was almost no statistical difference between the VMAT and IMRT. There was also a reduction in monitor units of approximately 32% from IMRT to VMAT with both modalities demonstrating comparable quality assurance results. VMAT provides comparable coverage of target volumes while sparing OARs for the majority of head and neck cases. In cases where high dose modulation was required for OARs, a clinically acceptable plan was only achievable with IMRT. Due to the long calculation times, VMAT plans can cause delays during planning but marked improvements in delivery time reduce patient treatment times and the risk of intra-fraction motion.
Collapse
|
36
|
Lu SH, Cheng JCH, Kuo SH, Lee JJS, Chen LH, Wu JK, Chen YH, Chen WY, Wen SY, Chong FC, Wu CJ, Wang CW. Volumetric modulated arc therapy for nasopharyngeal carcinoma: A dosimetric comparison with TomoTherapy and step-and-shoot IMRT. Radiother Oncol 2012; 104:324-30. [DOI: 10.1016/j.radonc.2011.11.017] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 11/14/2011] [Accepted: 11/28/2011] [Indexed: 11/30/2022]
|
37
|
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.
Collapse
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
| |
Collapse
|
38
|
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.
Collapse
Affiliation(s)
- James C L Chow
- Radiation Medicine Program, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada.
| | | |
Collapse
|
39
|
Treutwein M, Hipp M, Koelbl O, Dobler B. Searching standard parameters for volumetric modulated arc therapy (VMAT) of prostate cancer. Radiat Oncol 2012; 7:108. [PMID: 22784505 PMCID: PMC3434122 DOI: 10.1186/1748-717x-7-108] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 02/17/2012] [Indexed: 12/25/2022] Open
Abstract
Background Since December 2009 a new VMAT planning system tool is available in Oncentra® MasterPlan v3.3 (Nucletron B.V.). The purpose of this study was to work out standard parameters for the optimization of prostate cancer. Methods For ten patients with localized prostate cancer plans for simultaneous integrated boost were optimized, varying systematically the number of arcs, collimator angle, the maximum delivery time, and the gantry spacing. Homogeneity in clinical target volume, minimum dose in planning target volume, median dose in the organs at risk, maximum dose in the posterior part of the rectum, and number of monitor units were evaluated using student’s test for statistical analysis. Measurements were performed with a 2D-array, taking the delivery time, and compared to the calculation by the gamma method. Results Plans with collimator 45° were superior to plans with collimator 0°. Single arc resulted in higher minimum dose in the planning target volume, but also higher dose values to the organs at risk, requiring less monitor units per fraction dose than dual arc. Single arc needs a higher value (per arc) for the maximum delivery time parameter than dual arc, but as only one arc is needed, the measured delivery time was shorter and stayed below 2.5 min versus 3 to 5 min. Balancing plan quality, dosimetric results and calculation time, a gantry spacing of 4° led to optimal results. Conclusion A set of parameters has been found which can be used as standard for volumetric modulated arc therapy planning of prostate cancer.
Collapse
Affiliation(s)
- Marius Treutwein
- Department of Radiation Oncology, Regensburg University Medical Center, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
| | | | | | | |
Collapse
|
40
|
Liu T, Chen J, Gong G, Zhang G, Bai T, Sun T, Lu J, Ma C, Yin Y. Radiation therapy for nasopharyngeal carcinoma using simultaneously integrated boost (SIB) protocol: a comparison planning study between intensity modulated arc radiotherapy vs. intensity modulated radiotherapy. Technol Cancer Res Treat 2012; 11:415-20. [PMID: 22568626 DOI: 10.7785/tcrt.2012.500262] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The aim of this paper is to compare the dosimetric difference between intensity-modulated arc therapy (IMAT) and conventional intensity-modulated radiation therapy (IMRT) for radiotherapy of nasopharyngeal carcinoma (NPC) using simultaneously integrated boost (SIB) protocol. Ten patients with nasopharyngeal carcinoma underwent SIB protocol were retrospectively studied. The plan target volume (PTV) of NPC contained nasopharynx gross target volume and the positive neck lymph nodes, PTV1 contained the high-risk sites of microscopic extension and the whole nasopharynx and PTV2 contained the low-risk sites. The prescription dose of PTV was 66 Gy/30 fractions, and for PTV1 60 Gy/30 fractions and for PTV2 54 Gy/30 fractions. IMAT (two 358° arcs) and IMRT (7 fields) plans were designed for each patients using SIB strategies. The monitor unit (MU), treatment time (T) and dosimetric difference between IMRT and IMAT were compared. IMAT can achieve better conformal index (CI) than IMRT (P < 0.05) for all PTVs, while no significant difference were found in homogeneity index (HI) (P > 0.05). There's no significant difference found in radiation dose of brain stem, lenses and parotids, while the maximum dose of spinal cord of IMAT was higher than IMRT (P < 0.05). The monitor unit of IMRT (1308 ± 213) was more than IMAT (606 ± 96) (P < 0.05), while the treatment time of IMRT (540 ± 160S) was more than IMAT (160 ± 10S). This study shows that IMAT using SIB strategies for NPC radiotherapy can achieve similar target coverage with better conformity with less MU and delivery time comparing to IMRT.
Collapse
Affiliation(s)
- Tonghai Liu
- Department of Radiation Oncology, Shandong Cancer Hospital, Shandong Provincial Key Laboratory of Radiation Oncology, Shandong Academy of Medical Sciences, Jinan, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Fung-Kee-Fung SD, Hackett R, Hales L, Warren G, Singh AK. A prospective trial of volumetric intensity-modulated arc therapy vs conventional intensity modulated radiation therapy in advanced head and neck cancer. World J Clin Oncol 2012; 3:57-62. [PMID: 22553505 PMCID: PMC3341741 DOI: 10.5306/wjco.v3.i4.57] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 02/15/2012] [Accepted: 04/01/2012] [Indexed: 02/06/2023] Open
Abstract
AIM: To prospectively compare volumetric intensity-modulated arc therapy (VMAT) and conventional intensity-modulated radiation therapy (IMRT) in coverage of planning target volumes and avoidance of multiple organs at risk (OARs) in patients undergoing definitive chemoradiotherapy for advanced (stage III or IV) squamous cell cancer of the head and neck.
METHODS: Computed tomography scans of 20 patients with advanced tumors of the larynx, naso-, oro- and hypopharynx were prospectively planned using IMRT (7 field) and VMAT using two arcs. Calculated doses to planning target volume (PTV) and OAR were compared between IMRT and VMAT plans. Dose-volume histograms (DVH) were utilized to obtain calculated doses to PTV and OAR, including parotids, cochlea, spinal cord, brainstem, anterior tongue, pituitary and brachial plexus. DVH’s for all structures were compared between IMRT and VMAT plans. In addition the plans were compared for dose conformity and homogeneity. The final treatment plan was chosen by the treating radiation oncologist.
RESULTS: VMAT was chosen as the ultimate plan in 18 of 20 patients (90%) because the plans were thought to be otherwise clinically equivalent. The IMRT plan was chosen in 2 of 20 patients because the VMAT plan produced concentric irradiation of the cord which was not overcome even with an avoidance structure. For all patients, VMAT plans had a lower number of average monitor units on average (MU = 542.85) than IMRT plans (MU = 1612.58) (P < 0.001). Using the conformity index (CI), defined as the 95% isodose volume divided by the PTV, the IMRT plan was more conformal with a lower conformity index (CI = 1.61) than the VMAT plan (CI = 2.00) (P = 0.003). Dose homogeneity, as measured by average standard deviation of dose distribution over the PTV, was not different with VMAT (1.45 Gy) or IMRT (1.73 Gy) (P = 0.069). There were no differences in sparing organs at risk.
CONCLUSION: In this prospective study, VMAT plans were chosen over IMRT 90% of the time. Compared to IMRT, VMAT plans used only one third of the MUs, had shorter treatment times, and similar sparing of OAR. Overall, VMAT provided similar dose homogeneity but less conformity in PTV irradiation compared to IMRT. This difference in conformity was not clinically significant.
Collapse
Affiliation(s)
- Simon D Fung-Kee-Fung
- Simon D Fung-Kee-Fung, Rachel Hackett, Lee Hales, Graham Warren, Anurag K Singh, Department of Radiation Medicine, Roswell Park Cancer Institute, University at Buffalo School of Medicine, Elm and Carlton Streets, Buffalo, NY 14214, United States
| | | | | | | | | |
Collapse
|
42
|
Teoh M, Clark CH, Wood K, Whitaker S, Nisbet A. Volumetric modulated arc therapy: a review of current literature and clinical use in practice. Br J Radiol 2011; 84:967-96. [PMID: 22011829 DOI: 10.1259/bjr/22373346] [Citation(s) in RCA: 431] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Volumetric modulated arc therapy (VMAT) is a novel radiation technique, which can achieve highly conformal dose distributions with improved target volume coverage and sparing of normal tissues compared with conventional radiotherapy techniques. VMAT also has the potential to offer additional advantages, such as reduced treatment delivery time compared with conventional static field intensity modulated radiotherapy (IMRT). The clinical worldwide use of VMAT is increasing significantly. Currently the majority of published data on VMAT are limited to planning and feasibility studies, although there is emerging clinical outcome data in several tumour sites. This article aims to discuss the current use of VMAT techniques in practice and review the available data from planning and clinical outcome studies in various tumour sites including prostate, pelvis (lower gastrointestinal, gynaecological), head and neck, thoracic, central nervous system, breast and other tumour sites.
Collapse
Affiliation(s)
- M Teoh
- Department of Oncology, St Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey, UK.
| | | | | | | | | |
Collapse
|
43
|
Lee TF, Chao PJ, Ting HM, Lo SH, Wang YW, Tuan CC, Fang FM, Su TJ. Comparative analysis of SmartArc-based dual arc volumetric-modulated arc radiotherapy (VMAT) versus intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma. J Appl Clin Med Phys 2011; 12:3587. [PMID: 22089015 PMCID: PMC5718754 DOI: 10.1120/jacmp.v12i4.3587] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 05/17/2011] [Accepted: 05/24/2011] [Indexed: 12/15/2022] Open
Abstract
The purpose of this study was to evaluate and quantify the planning performance of SmartArc‐based volumetric‐modulated arc radiotherapy (VMAT) versus fixed‐beam intensity‐modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC) using a sequential mode treatment plan. The plan quality and performance of dual arc‐VMAT (DA‐VMAT) using the Pinnacle3 Smart‐Arc system (clinical version 9.0; Philips, Fitchburg, WI, USA) were evaluated and compared with those of seven‐field (7F)‐IMRT in 18 consecutive NPC patients. Analysis parameters included the conformity index (CI) and homogeneity index (HI) for the planning target volume (PTV), maximum and mean dose, normal tissue complication probability (NTCP) for the specified organs at risk (OARs), and comprehensive quality index (CQI) for an overall evaluation in the 11 OARs. Treatment delivery time, monitor units per fraction (MU/fr), and gamma (Γ3mm,3%) evaluations were also analyzed. DA‐VMAT achieved similar target coverage and slightly better homogeneity than conventional 7F‐IMRT with a similar CI and HI. NTCP values were only significantly lower in the left parotid gland (for xerostomia) for DA‐VMAT plans. The mean value of CQI at 0.98±0.02 indicated a 2% benefit in sparing OARs by DA‐VMAT. The MU/fr used and average delivery times appeared to show improved efficiencies in DA‐VMAT. Each technique demonstrated high accuracy in dose delivery in terms of a high‐quality assurance (QA) passing rate (>98%) of the (Γ3mm,3%) criterion. The major difference between DA‐VMAT and 7F‐IMRT using a sequential mode for treating NPC cases appears to be improved efficiency, resulting in a faster delivery time and the use of fewer MU/fr. PACS number: 87.53.Tf, 87.55.x, 87.55.D, 87.55.dk
Collapse
Affiliation(s)
- Tsair-Fwu Lee
- Medical Physics & Informatics Lab., Department of Electronics Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung, Taiwan.
| | | | | | | | | | | | | | | |
Collapse
|