Stiefel I, Schröder C, Tanadini-Lang S, Pytko I, Vu E, Klement R J, Guckenberger M, Andratschke N
Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland.
Center for Proton Therapy, Paul Scherrer-Institut, Villigen, Switzerland.
Clin Transl Radiat Oncol. 2021 Feb 4;27:132-138. doi: 10.1016/j.ctro.2021.01.011. eCollection 2021 Mar.
The use of cranial re-irradiation is growing with improving overall survival and the advent of high-precision radiotherapy techniques. Still the value of re-irradiation needs careful evaluation regarding safety and efficacy. We analyzed dosimetric and clinical data of patients receiving cranial re-irradiation using EQD2 sum plans.
We retrospectively analyzed the data of 76 patients who received repeated cranial radiotherapy from 02/2013 to 09/2016. 34 patients suffered from recurrent primary brain tumors, 42 from brain metastases. Dosimetric analysis was performed accumulating EQD2 dose distributions based on rigid image registration. Clinical and radiological data was collected at follow-ups including toxicity, local control and overall survival.
In total 76 patients had at least 2 courses of intracranial radiotherapy. The median accumulated prescription EQD2 dose was 96.5 Gy for all radiation courses combined. The median D(0.1 cc) of the brain for patients receiving more than 100 Gy was 114 Gy with a highest dose of 161.5 Gy. 74% of patients suffered from low grade (G1-G2) acute toxicity, only two high grade (>G3) toxicities were recorded.Median overall survival from the time of first re-irradiation was 57 weeks (range 4-186 weeks). The median time to local failure for patients with a primary brain tumor was not reached and 24 weeks (range 1-77 weeks) for patients with brain metastases.
Repeated radiotherapy appears both safe and efficient in patients with recurrent primary or secondary brain tumors with doses to the brain up to 120 Gy EQD2, doses below 100 Gy for brainstem and doses below 75 Gy EQD2 to chiasm and optic nerves.
随着总体生存率的提高以及高精度放射治疗技术的出现，颅再程放疗的应用日益增多。然而，再程放疗在安全性和有效性方面的价值仍需仔细评估。我们使用等效均匀剂量（EQD2）总和计划分析了接受颅再程放疗患者的剂量学和临床数据。
我们回顾性分析了2013年2月至2016年9月期间接受重复颅部放疗的76例患者的数据。34例患者患有原发性脑肿瘤复发，42例患有脑转移瘤。基于刚性图像配准累积EQD2剂量分布进行剂量学分析。在随访中收集临床和放射学数据，包括毒性、局部控制和总生存期。
总共76例患者至少接受了2个疗程的颅内放疗。所有放疗疗程合并后的累积处方EQD2剂量中位数为96.5 Gy。接受超过100 Gy放疗的患者，脑的D(0.1 cc)中位数为114 Gy，最高剂量为161.5 Gy。74%的患者出现低级别（G1 - G2）急性毒性，仅记录到2例高级别（>G3）毒性反应。从首次再程放疗开始计算，总生存期中位数为57周（范围4 - 186周）。原发性脑肿瘤患者未达到局部失败的中位时间，脑转移瘤患者为24周（范围1 - 77周）。
对于原发性或继发性脑肿瘤复发的患者，重复放疗似乎是安全有效的，脑的剂量可达120 Gy EQD2，脑干剂量低于100 Gy，视交叉和视神经剂量低于75 Gy EQD2。
