Impact of daily plan adaptation on accumulated doses in ultra-hypofractionated magnetic resonance-guided radiation therapy of prostate cancer

Xiong Y, Rabe M, Rippke C, Kawula M, Nierer L, Klüter S, Belka C, Niyazi M, Hörner-Rieber J, Corradini S, Landry G, Kurz C (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Physics and Imaging in Radiation Oncology Elsevier

Book Volume: 29

Article Number: 100562

DOI: 10.1016/j.phro.2024.100562

Abstract

Background and purpose: Ultra-hypofractionated online adaptive magnetic resonance-guided radiotherapy (MRgRT) is promising for prostate cancer. However, the impact of online adaptation on target coverage and organ-at-risk (OAR) sparing at the level of accumulated dose has not yet been reported. Using deformable image registration (DIR)-based accumulation, we compared the delivered adapted dose with the simulated non-adapted dose. Materials and methods: Twenty-three prostate cancer patients treated at two clinics with 0.35 T magnetic resonance-guided linear accelerator (MR-linac) following the same treatment protocol (5 × 7.5 Gy with urethral sparing and daily adaptation) were included. The fraction MR images were deformably registered to the planning MR image. Both non-adapted and adapted fraction doses were accumulated with the corresponding vector fields. Two DIR approaches were implemented. PTV* (planning target volume minus urethra+2mm) D95%, CTV* (clinical target volume minus urethra) D98%, and OARs (urethra+2mm, bladder, and rectum) D0.2cc, were evaluated. Statistical significance was inferred from a two-tailed Wilcoxon signed-rank test (p < 0.05). Results: Normalized to the baseline, the accumulated PTV* D95% increased significantly by 2.7 % ([1.5, 4.3]%) through adaptation, and the CTV* D98% by 1.2 % ([0.1, 1.7]%). For the OARs after adaptation, accumulated bladder D0.2cc decreased by 0.4 % ([−1.2, 0.4]%), urethra+2mm D0.2cc by 0.8 % ([−1.6, −0.1]%), while rectum D0.2cc increased by 2.6 % ([1.2, 4.9]%). For all patients, rectum D0.2cc was still below the clinical constraint. Results of both DIR approaches differed on average by less than 0.2 %. Conclusions: Online adaptation in MRgRT improved target coverage and OARs sparing at the level of accumulated dose.

Involved external institutions

Klinikum der Universität München (LMU Klinikum) DE Germany (DE) Universitätsklinikum Heidelberg DE Germany (DE)

How to cite

APA:

Xiong, Y., Rabe, M., Rippke, C., Kawula, M., Nierer, L., Klüter, S.,... Kurz, C. (2024). Impact of daily plan adaptation on accumulated doses in ultra-hypofractionated magnetic resonance-guided radiation therapy of prostate cancer. Physics and Imaging in Radiation Oncology, 29. https://doi.org/10.1016/j.phro.2024.100562

MLA:

Xiong, Yuqing, et al. "Impact of daily plan adaptation on accumulated doses in ultra-hypofractionated magnetic resonance-guided radiation therapy of prostate cancer." Physics and Imaging in Radiation Oncology 29 (2024).

BibTeX: Download