Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, USA; Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, University of Bergen, Norway; Department of Physics and Technology, University of Bergen, Norway.
Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, USA.
Radiother Oncol. 2020 Oct;151:119-125. doi: 10.1016/j.radonc.2020.07.008. Epub 2020 Jul 15.
To characterize patterns and outcomes of brain MR image changes after proton therapy (PT) for skull base head and neck cancer (HNC).
Post-treatment MRIs ≥6 months were reviewed for radiation-associated image changes (RAIC) in 127 patients. All patients had received at least a point dose of 40 Gy(RBE) to the brain. The MRIs were rigidly registered to planning CTs and RAIC lesions were contoured both on T1 weighted (post-contrast) and T2 weighted sequences, and dose-volume parameters extracted. Probability of RAIC was calculated using multistate survival analysis. Univariate/multivariate analyses were performed using Cox Regression. Recursive partitioning analysis was used to investigate dose-volume correlates of RAIC development.
17.3% developed RAIC. All RAIC events were asymptomatic and occurred in the temporal lobe (14), frontal lobe (6) and cerebellum (2). The median volume of the contrast enhanced RAIC lesion was 0.5 cc at their maximum size. The RAIC resolved or improved in 45.5% of the patients and were stable or progressed in 36.4%. The 3-year actuarial rate of developing RAIC was 14.3%. RAIC was observed in 63% of patients when V of the brain ≥0.17 cc.
Small RAIC lesions after PT occurred in 17.3% of the patients; the majority in nasopharyngeal or sinonasal cancer. The estimated dose-volume correlations confirm the importance of minimizing focal high doses to brain when achievable.
为了描述质子治疗（PT）后颅底头颈部癌症（HNC）患者脑部磁共振成像（MRI）变化的模式和结果。
回顾了 127 例患者的治疗后≥6 个月的 MRI，以评估与放射相关的图像变化（RAIC）。所有患者的大脑至少接受了 40 Gy（RBE）的点剂量照射。MRI 与计划 CT 进行刚性配准，在 T1 加权（增强后）和 T2 加权序列上对 RAIC 病变进行轮廓勾画，并提取剂量-体积参数。使用多状态生存分析计算 RAIC 的概率。使用 Cox 回归进行单变量/多变量分析。使用递归分区分析来研究 RAIC 发展的剂量-体积相关性。
17.3%的患者发生了 RAIC。所有 RAIC 事件均无症状，发生在颞叶（14 例）、额叶（6 例）和小脑（2 例）。RAIC 增强病变的最大体积中位数为 0.5 cc。45.5%的患者 RAIC 缓解或改善，36.4%的患者 RAIC 稳定或进展。3 年 RAIC 发生率为 14.3%。当大脑 V 体积≥0.17 cc 时，63%的患者出现 RAIC。
PT 后出现的小 RAIC 病变发生在 17.3%的患者中，主要发生在鼻咽癌或鼻窦癌患者中。估计的剂量-体积相关性证实了在可行的情况下，尽量减少大脑局灶性高剂量照射的重要性。
