Dataset Information

Hypofractionated palliative volumetric modulated arc radiotherapy with the Radiation Oncology Study Group 8502 "QUAD shot" regimen for incurable head and neck cancer.

ABSTRACT: BACKGROUND:To review a single institutional experience of the Radiation Therapy Oncology Group (RTOG) 8502 "QUAD shot" regimen using volumetric modulated arc radiotherapy (VMAT) for incurable head and neck cancer (HNC). METHODS:Thirty-four consecutive patients with HNC were treated with at least one cycle of the RTOG 8502 regimen. Treatment plans included the use of VMAT with 6 MV photons generated by a linear accelerator. Two daily fractions of 3.7?Gy were delivered with an interval of at least 6?h for 2 consecutive days, totaling 14.8?Gy over 4 fractions. This was repeated every 3-4?weeks for a total of three cycles. No concurrent systemic therapy was performed. RESULTS:The number of completed cycles was 1 in 6 (18%) patients, 2 in 5 (15%), and 3 in 23 (68%). Tumor response was achieved in 29 (85%) patients and symptom relief in 20 (77%) of 26 patients. Overall response (tumor response or symptom relief) was achieved in 32 (94%) patients. All patients who received 2 or more treatment cycles achieved overall response. Median overall survival (OS) was 5.7?months. Multivariate analysis revealed that completion of all three treatment cycles was significantly associated with better OS (P?=?0.002). Grade 2 toxicity was observed in four (12%) patients, but no acute Grade???3 or late toxicity was observed. CONCLUSIONS:The RTOG 8502 "QUAD shot" regimen using VMAT is effective for incurable HNC with highly reduced toxicity. Treatment with multiple cycles is recommended for better treatment response and/or survival.

SUBMITTER: Toya R

PROVIDER: S-EPMC7251877 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Hypofractionated palliative volumetric modulated arc radiotherapy with the Radiation Oncology Study Group 8502 "QUAD shot" regimen for incurable head and neck cancer.

Toya Ryo R Saito Tetsuo T Yamaguchi Kohsei K Matsuyama Tomohiko T Watakabe Takahiro T Matsumoto Tadashi T Yoshida Ryoji R Hirosue Akiyuki A Murakami Daizo D Orita Yorihisa Y Nakayama Hideki H Oya Natsuo N

Radiation oncology (London, England) 20200527 1

<h4>Background</h4>To review a single institutional experience of the Radiation Therapy Oncology Group (RTOG) 8502 "QUAD shot" regimen using volumetric modulated arc radiotherapy (VMAT) for incurable head and neck cancer (HNC).<h4>Methods</h4>Thirty-four consecutive patients with HNC were treated with at least one cycle of the RTOG 8502 regimen. Treatment plans included the use of VMAT with 6 MV photons generated by a linear accelerator. Two daily fractions of 3.7 Gy were delivered with an inter ...[more]

PMID: 32460865

Similar Datasets

Project description:Hypofractionated treatments generally increase the complexity of a treatment plan due to the more stringent constraints of normal tissues and target coverage. As a result, treatment plans contain more modulated MLC motions that may require extra efforts for accurate dose calculation. This study explores methods to minimize the differences between in-house dose calculation and actual delivery of hypofractionated volumetric-modulated arc therapy (VMAT), by focusing on arc approximation and tongue-and-groove (TG) modeling. For dose calculation, the continuous delivery arc is typically approximated by a series of static beams with an angular spacing of 2°. This causes significant error when there is large MLC movement from one beam to the next. While increasing the number of beams will minimize the dose error, calculation time will increase significantly. We propose a solution by inserting two additional apertures at each of the beam angle for dose calculation. These additional apertures were interpolated at two-thirds' degree before and after each beam. Effectively, there were a total of three MLC apertures at each beam angle, and the weighted average fluence from the three apertures was used for calculation. Because the number of beams was kept the same, calculation time was only increased by about 6%-8%. For a lung plan, areas of high local dose differences (> 4%) between film measurement and calculation with one aperture were significantly reduced in calculation with three apertures. Ion chamber measurement also showed similar results, where improvements were seen with calculations using additional apertures. Dose calculation accuracy was further improved for TG modeling by developing a sampling method for beam fluence matrix. Single element point sampling for fluence transmitted through MLC was used for our fluence matrix with 1 mm resolution. For Varian HDMLC, grid alignment can cause fluence sampling error. To correct this, transmission volume averaging was applied. For three paraspinal HDMLC cases, the average dose difference was greatly reduced in film and calculation comparisons with our new approach. The gamma (3%, 3 mm) pass rates have improved significantly from 74.1%, 90.0%, and 90.4% to 99.2%, 97.9%, and 97.3% for three cases, for calculation without volume averaging and calculation with volume averaging, respectively. Our results indicate that more accurate MLC leaf position and transmission sampling can improve accuracy and agreement between calculation and measurement, and are particularly important for hypofractionated VMAT that consists of large MLC movement.

Dataset Information

Hypofractionated palliative volumetric modulated arc radiotherapy with the Radiation Oncology Study Group 8502 "QUAD shot" regimen for incurable head and neck cancer.

Publications

Hypofractionated palliative volumetric modulated arc radiotherapy with the Radiation Oncology Study Group 8502 "QUAD shot" regimen for incurable head and neck cancer.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets