Han Jeongmin, Lee Seong Wook, Han Na Young, Gwak Ho-Shin
Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Korea.
Department of Radiation Oncology, National Cancer Center, Goyang, Korea.
Brain Tumor Res Treat. 2024 Apr;12(2):141-147. doi: 10.14791/btrt.2024.0017.
Delayed cerebral necrosis is a well-known complication of radiation therapy (RT). Because of its irreversible nature, it should be avoided if possible, but avoidance occurs at the expense of potentially compromised tumor control, despite the use of the modern advanced technique of conformal RT that minimizes radiation to normal brain tissue. Risk factors for radiation-induced cerebral necrosis include a higher dose per fraction, larger treatment volume, higher cumulative dose, and shorter time interval (for re-irradiation). The same principle can be applied to proton beam therapy (PBT) to avoid delayed cerebral necrosis. However, conversion of PBT radiation energy into conventional RT is still short of clinical support, compared to conventional RT. Herein, we describe two patients with excessively delayed cerebral necrosis after PBT, in whom follow-up MRI showed no RT-induced changes prior to 3 years after treatment. One patient developed radiation necrosis at 4 years after PBT to the resection cavity of an astroblastoma, and the other developed brainstem necrosis that became symptomatic 6 months after its first appearance on the 3-year follow-up brain MRI. We also discuss possible differences between radiation changes after PBT versus conventional RT.
迟发性脑坏死是放射治疗（RT）的一种众所周知的并发症。由于其不可逆的性质，应尽可能避免，但尽管使用了能将对正常脑组织的辐射降至最低的现代先进适形放疗技术，避免该并发症却可能以肿瘤控制受到潜在影响为代价。放射性脑坏死的危险因素包括每次分割剂量较高、治疗体积较大、累积剂量较高以及时间间隔较短（再次放疗时）。同样的原则也可应用于质子束治疗（PBT）以避免迟发性脑坏死。然而，与传统放疗相比，PBT辐射能量转换为传统放疗仍缺乏临床支持。在此，我们描述了两名接受PBT后发生过度迟发性脑坏死的患者，其随访MRI显示在治疗后3年内无放疗引起的变化。一名患者在PBT治疗成纤维细胞瘤切除腔4年后发生放射性坏死，另一名患者在3年随访脑部MRI首次出现脑干坏死6个月后出现症状。我们还讨论了PBT与传统放疗后放射学改变的可能差异。
