Crouzen J A, Zindler J D, Mast M E, Kleijnen J J E, Versluis M C, Hashimzadah M, Kiderlen M, van der Voort van Zyp N C M G, Broekman M L D, Petoukhova A L
Department of Radiotherapy, Haaglanden Medical Center, Lijnbaan 32, 2512 VA, The Hague, The Netherlands.
Department of Radiotherapy, HollandPTC, Huismansingel 4, 2629 JH, Delft, The Netherlands.
Sci Rep. 2025 May 5;15(1):15722. doi: 10.1038/s41598-025-01034-x.
Stereotactic radiotherapy (SRT) is frequently used to treat brain metastases (BMs). The single-isocenter for multiple targets (SIMT) technique allows for faster treatment of large numbers of BMs, but may adversely affect planning target volume (PTV) coverage due to possible increased positioning uncertainties with an increased isocenter to tumor distance (ITD). This study aims to investigate the association of ITD with local recurrence (LR) and radionecrosis (RN). Patients treated with SRT using a single isocenter for multiple BMs were retrospectively analyzed. Previous cranial radiotherapy and inability to undergo MR imaging were exclusion criteria. Patients were irradiated using a Versa HD LINAC with 6 MV flattening filter-free (FFF) energy and a 6D robotic couch. A non-coplanar volumetric modulated arc technique was used and plans were delivered using 6MV FFF energy. Associations between potential risk factors and LR/RN were investigated with Cox regression analyses. Seventy-five patients with a total of 357 BMs were included. Median survival after SRT was nine months. LR occurred in 7 (9%) patients and 10 (13%) had RN. After 18 months, LR-free survival was 89% and RN-free survival was 85%, respectively. ITD was not significantly associated with LR and RN. GTV was significantly associated with both LR (HR 1.10, 95% CI 1.02-1.17, P 0.0079) and RN (HR 1.09, 95% CI 1.01-1.17, P 0.020). LINAC-based SIMT SRT is a safe and effective treatment modality for patients with multiple BMs. We found no increased risk of LR or RN for BMs located further away from the isocenter.
立体定向放射治疗（SRT）常用于治疗脑转移瘤（BMs）。多靶区单等中心（SIMT）技术可加快大量脑转移瘤的治疗速度，但由于随着等中心到肿瘤距离（ITD）增加，定位不确定性可能增加，可能会对计划靶体积（PTV）覆盖产生不利影响。本研究旨在探讨ITD与局部复发（LR）和放射性坏死（RN）之间的关联。对使用单等中心SRT治疗多个脑转移瘤的患者进行回顾性分析。既往有颅脑放疗史及无法进行磁共振成像为排除标准。患者使用配备6MV无均整器（FFF）能量的Versa HD直线加速器和6D机器人治疗床进行照射。采用非共面容积调强弧形技术，并使用6MV FFF能量进行计划投照。通过Cox回归分析研究潜在危险因素与LR/RN之间的关联。纳入75例患者，共357个脑转移瘤。SRT后的中位生存期为9个月。7例（9%）患者发生LR，10例（13%）发生RN。18个月后，无LR生存率和无RN生存率分别为89%和85%。ITD与LR和RN均无显著关联。GTV与LR（HR 1.10，95%CI 1.02-1.17，P 0.0079）和RN（HR 1.09，95%CI 1.01-1.17，P 0.020）均显著相关。基于直线加速器的SIMT SRT是治疗多个脑转移瘤患者的一种安全有效的治疗方式。我们发现距离等中心较远的脑转移瘤发生LR或RN的风险并未增加。
