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Saglam Y, Bolukbasi Y, Atasoy AI, Karakose F, Budak M, Alpan V, Topkan E, Selek U. Novel Clinically Weight-Optimized Dynamic Conformal Arcs (WO-DCA) for Liver SBRT: A Comparison with Volumetric Modulated Arc Therapy (VMAT). Ther Clin Risk Manag 2021; 17:1053-1064. [PMID: 34611405 PMCID: PMC8487279 DOI: 10.2147/tcrm.s328375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/11/2021] [Indexed: 12/28/2022] Open
Abstract
PURPOSE To evaluate the feasibility of shortening the duration of liver stereotactic radiotherapy (SBRT) without jeopardizing dosimetry or conformity by utilizing weight-optimized dynamic conformal arcs (WO-DCA) as opposed to volumetric modulated arc therapy (VMAT) for tumors away from critical structures. METHODS Nineteen patients with liver metastasis were included, previously treated with 50 Gy in 4 fractions with VMAT technique using two partial coplanar arcs of 6 MV beams delivered in high-definition multi-leaf collimator (HD-MLC). Two coplanar partial WO-DCA were generated on Pinnacle treatment planning system (TPS) for each patient; and MLC aperture around the planning target volume (PTV) was automatically generated at different margins for both arcs and maintained dynamically around the target during arc rotation. Weight of the two arcs using optimization method was adjusted between the arcs to maximize tumor coverage and protect organs at risk (OAR) based on the RTOG-0438 protocol. RESULTS The WO-DCA plans successfully "agreed" with the standard VMAT for OAR (liver, spinal cord, stomach, duodenum, small bowel, and heart) and PTV (Dmean, D98%, D2%, CI, and GI), with superior mean quality assurance (QA) pass rate (97.06 vs 93.00 for VMAT; P < 0.001 and t = 8.87). Similarly, the WO-DCA technique additionally reduced the beam-on time (3.26 vs 4.43; P < 0.001) and monitor unit (1860 vs 2705 for VMAT; P < 0.001) values significantly. CONCLUSION The WO-DCA plans might minimize small-field dosimetry errors and defeat patient-specific VMAT QA requirements due to the omission of MLC beam modulation through the target volume. The WO-DCA plans may additionally enable faster treatment delivery times and lower OAR without sacrificing target doses in SBRT of liver tumors away from critical structures.
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Affiliation(s)
- Yucel Saglam
- Koc University, School of Medicine, Department of Radiation Oncology, Istanbul, Turkey
- UT MD Anderson Radiation Oncology Outreach Center at American Hospital, Istanbul, Turkey
| | - Yasemin Bolukbasi
- Koc University, School of Medicine, Department of Radiation Oncology, Istanbul, Turkey
- UT MD Anderson Radiation Oncology Outreach Center at American Hospital, Istanbul, Turkey
- University of Texas, MD Anderson Cancer Center, Department of Radiation Oncology, Houston, TX, USA
| | - Ali Ihsan Atasoy
- Koc University, School of Medicine, Department of Radiation Oncology, Istanbul, Turkey
| | - Fatih Karakose
- Koc University, School of Medicine, Department of Radiation Oncology, Istanbul, Turkey
| | - Mustafa Budak
- Koc University, School of Medicine, Department of Radiation Oncology, Istanbul, Turkey
| | - Vildan Alpan
- Koc University, School of Medicine, Department of Radiation Oncology, Istanbul, Turkey
- UT MD Anderson Radiation Oncology Outreach Center at American Hospital, Istanbul, Turkey
| | - Erkan Topkan
- Baskent University Medical Faculty, Department of Radiation Oncology, Adana, Turkey
| | - Ugur Selek
- Koc University, School of Medicine, Department of Radiation Oncology, Istanbul, Turkey
- UT MD Anderson Radiation Oncology Outreach Center at American Hospital, Istanbul, Turkey
- University of Texas, MD Anderson Cancer Center, Department of Radiation Oncology, Houston, TX, USA
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Han S, Yin FF, Cai J. Evaluation of dosimetric uncertainty caused by MR geometric distortion in MRI-based liver SBRT treatment planning. J Appl Clin Med Phys 2019; 20:43-50. [PMID: 30697915 PMCID: PMC6370985 DOI: 10.1002/acm2.12520] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 11/09/2018] [Accepted: 11/24/2018] [Indexed: 11/12/2022] Open
Abstract
PURPOSE MRI-based treatment planning is a promising technique for liver stereotactic-body radiation therapy (SBRT) treatment planning to improve target volume delineation and reduce radiation dose to normal tissues. MR geometric distortion, however, is a source of potential error in MRI-based treatment planning. The aim of this study is to investigate dosimetric uncertainties caused by MRI geometric distortion in MRI-based treatment planning for liver SBRT. MATERIALS AND METHODS The study was conducted using computer simulations. 3D MR geometric distortion was simulated using measured data in the literature. Planning MR images with distortions were generated by integrating the simulated 3D MR geometric distortion onto planning CT images. MRI-based treatment plans were then generated on the planning MR images with two dose calculation methods: (1) using original CT numbers; and (2) using organ-specific assigned CT numbers. Dosimetric uncertainties of various dose-volume-histogram parameters were determined as their differences between the simulated MRI-based plans and the original clinical CT-based plans for five liver SBRT cases. RESULTS The average simulated distortion for the five liver SBRT cases was 2.77 mm. In the case of using original CT numbers for dose calculation, the average dose uncertainties for target volumes and critical structures were <0.5 Gy, and the average target volume percentage at prescription dose uncertainties was 0.97%. In the case of using assigned CT numbers, the average dose uncertainties for target volumes and critical structures were <1.0 Gy, and the average target volume percentage at prescription dose uncertainties was 2.02%. CONCLUSIONS Dosimetric uncertainties caused by MR geometric distortion in MRI-based liver SBRT treatment planning was generally small (<1 Gy) when the distortion is 3 mm.
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Affiliation(s)
- Silu Han
- Medical Physics Graduate Program, Duke University Medical Center, Durham, NC, USA.,Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA
| | - Fang-Fang Yin
- Medical Physics Graduate Program, Duke University Medical Center, Durham, NC, USA.,Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Jing Cai
- Medical Physics Graduate Program, Duke University Medical Center, Durham, NC, USA.,Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA.,Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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Willett CG, Moughan J, O'Meara E, Galvin JM, Crane CH, Winter K, Manfredi D, Rich TA, Rabinovitch R, Lustig R, Machtay M, Curran WJ. Compliance with therapeutic guidelines in Radiation Therapy Oncology Group prospective gastrointestinal clinical trials. Radiother Oncol 2012; 105:9-13. [PMID: 23084596 PMCID: PMC4106147 DOI: 10.1016/j.radonc.2012.09.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 09/11/2012] [Accepted: 09/12/2012] [Indexed: 12/13/2022]
Abstract
BACKGROUND This report analyzes the adherence to radiation therapy protocol guidelines in contemporary Radiation Therapy Oncology Group (RTOG) gastrointestinal trials. We aim to provide insight into current standards and compliance of radiation therapy field design and administration. METHODS From 1994 to 2006, the Gastrointestinal Cancer Committee of the RTOG initiated and completed 15 phase I-III clinical trials utilizing radiation therapy in the multimodality treatment of gastrointestinal cancers. In each protocol, details for planning and executing radiation therapy were outlined and each protocol contained scoring criteria for these components of radiation therapy, characterized according to per-protocol, variation acceptable and deviation unacceptable. Review of treatment planning and implementation was performed in all studies following therapy completion. RESULTS Radiation therapy planning and implementation was reviewed in 2309 of 2312 (99.9%) patients. The mean rate of compliance over all for the 15 protocols was 65% (total of the 2309 analyzed patients). The mean variation acceptable rate was 21% whereas the mean deviation unacceptable rate was 5%. The mean "other" rate (no RT given or incomplete RT due to death, progression or refusal) was 8%. Two of the 15 trials (13%) had deviation unacceptable rates >10%. In four studies incorporating pre-treatment review of radiation therapy planning and treatment, compliance with protocol therapy was enhanced. CONCLUSIONS The fidelity of radiation planning and execution detailed in protocol to actual therapy is heterogeneous, with a mean per-protocol rate of 65%. As clinical trials evolve, available technology should permit efficient pre-treatment review processes, thus facilitating compliance to protocol therapy. These analyses should also permit prospective analysis of outcome measures by compliance to therapy.
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