The HyperArc technique is known for generating high-quality radiosurgical treatment plans for intracranial lesions or hippocampal-sparing whole-brain radiotherapy (WBRT). However, there is no reported feasibility of using the HyperArc technique in hippocampal-sparing WBRT with a simultaneous integrated boost (SIB). This study aimed to compare dosimetric parameters of 2 commercially-available volumetric-modulated arc radiotherapy techniques, HyperArc and RapidArc, when using hippocampal-sparing WBRT with a SIB to treat brain metastases. Treatment plans using HyperArc and RapidArc techniques were generated retrospectively for 19 previously treated patients (1 to 3 brain metastases). The planning target volumes for the whole brain (excluding the hippocampal avoidance region; PTV) and metastases (PTV) were prescribed 25 and 45 Gy, respectively, in 10 fractions. Each plan included homogeneous and inhomogeneous delivery to the PTV. Dosimetric parameters for the target (conformity index [CI], homogeneity index [HI], target coverage [D]), and nontarget organs at risk were compared for the HyperArc and RapidArc plans. For homogeneous delivery, dosimetric parameters, including mean CI, HI, and target coverage in PTV and PTV, were superior for HyperArc than RapidArc plans (all p < 0.01). The PTV and PTV target coverage for HyperArc plans was significantly greater than for RapidArc plans (96.17% vs 93.38%, p < 0.01; 94.02% vs 92.21%, p < 0.01, respectively). HyperArc plans had significantly lower mean hippocampal D and D values than RapidArc plans (D: 15.53 Gy vs, 16.71 Gy, p < 0.01; D: 8.33 Gy vs 8.93 Gy, p < 0.01, respectively). Similarly, inhomogeneous delivery of hyperArc produced a superior target and lower hippocampal dosimetric parameters than RapidArc, except for the HI of PTV (all p < 0.01). HyperArc generated superior conformity and target coverage with lower hippocampal doses than RapidArc. HyperArc could be an attractive technique for hippocampal-sparing WBRT with an SIB.
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http://dx.doi.org/10.1016/j.meddos.2023.08.007 | DOI Listing |
Nan Fang Yi Ke Da Xue Xue Bao
December 2024
School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China.
Pract Radiat Oncol
December 2024
Mayo Clinic, Department of Radiation Oncology, Rochester, MN 55905.
Objectives: Spatially fractionated radiation therapy (SFRT) intentionally delivers a heterogeneous dose distribution characterized by alternating regions of high and low doses throughout a tumor. This modality may enhance response to subsequent whole tumor radiation in bulky and radioresistant lesions that are historically less responsive to conventional radiation doses alone. The current study presents a single institution experience with modern era SFRT using predominantly a volumetric modulated arc therapy (VMAT) lattice technique.
View Article and Find Full Text PDFJ Radiat Res
December 2024
Section of Radiation Safety and Quality Assurance, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan.
We assessed the effect of beam size on plan robustness for intensity-modulated proton therapy (IMPT) of head and neck cancer (HNC) and compared the plan quality including robustness with that of intensity-modulated radiation therapy (IMRT). IMPT plans were generated for six HNC patients using six beam sizes (air-sigma 3-17 mm at isocenter for a 70-230 MeV) and two optimization methods for planning target volume-based non-robust optimization (NRO) and clinical target volume (CTV)-based robust optimization (RO). Worst-case dosimetric parameters and plan robustness for CTV and organs-at-risk (OARs) were assessed under different scenarios, assuming a ± 1-5 mm setup error and a ± 3% range error.
View Article and Find Full Text PDFProbl Radiac Med Radiobiol
December 2024
Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Bethesda, MD 20892, USA.
Objective: Scientific justification of the methodology for calculating radiation internal doses from 137Cs and 134Cs intake for residents of Ukrainian settlements radioactively contaminated as a result of the Chornobyl (Chernobyl) accident in which measurements of incorporated radiocesium isotopes in humans using whole-body counters (WBC) were not carried out.
Materials And Methods: The paper presents a new methodology for reconstructing doses due to internal irradiation from Chornobyl fallout for both surface (in 1986) and root (in 1987-2023) contamination of vegetation with 137Cs and 134Cs and their transfer into the human body. The methodology for calculating the dose due to surface contamination of vegetation was based on the theoretical model of the transfer of radiocesium isotopes through the food chain with further adjustment of this model to the results of WBC measurements carried out between 15 July and 31 December 1986.
Front Oncol
December 2024
Radiotherapy Department, Montpellier Regional Cancer Institute, Montpellier, France.
Introduction: Following a preliminary work validating the technological feasibility of an adaptive workflow with Ethos for whole-breast cancer, this study aims to clinically evaluate the automatic segmentation generated by Ethos.
Material And Methods: Twenty patients initially treated on a TrueBeam accelerator for different breast cancer indications (right/left, lumpectomy/mastectomy) were replanned using the Ethos emulator. The adaptive workflow was performed using 5 randomly selected extended CBCTs per patient.
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