Zheng Lin, Zhou Zhi-Rui, Yu QianQian, Shi Minghan, Yang Yang, Zhou Xiaofeng, Li Chao, Wei Qichun
Department of Radiation Oncology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Department of Radiation Oncology, Taizhou Cancer Hospital, Wenling, China.
Front Oncol. 2021 Feb 22;10:615368. doi: 10.3389/fonc.2020.615368. eCollection 2020.
Radiotherapy is an important treatment for glioblastoma (GBM), but there is no consensus on the target delineation for GBM radiotherapy. The Radiation Therapy Oncology Group (RTOG) and European Organisation for Research and Treatment of Cancer (EORTC) each have their own rules. Our center adopted a target volume delineation plan based on our previous studies. This study focuses on the recurrence pattern of GBM patients whose target delineations did not intentionally include the T2/fluid-attenuated inversion recovery (FLAIR) hyperintensity area outside of the gross tumor volume (GTV). We prospectively collected 162 GBM cases and retrospectively analysed the clinical data and continuous dynamic magnetic resonance images (MRI) of 55 patients with recurrent GBM. All patients received concurrent radiotherapy and chemotherapy with temozolomide (TMZ). The GTV that we defined includes the postoperative T1-weighted MRI enhancement area and resection cavity. Clinical target volume 1 (CTV1) and CTV2 were defined as GTVs with 1 and 2 cm margins, respectively. Planning target volume 1 (PTV1) and PTV2 were defined as CTV1 and CTV2 plus a 3 mm margin with prescribed doses of 60 and 54 Gy, respectively. The first recurrent contrast-enhanced T1-weighted MRI was introduced into the Varian Eclipse radiotherapy planning system and fused with the original planning computed tomography (CT) images to determine the recurrence pattern. The median follow-up time was 15.8 months. The median overall survival (OS) and progression-free survival (PFS) were 17.7 and 7.0 months, respectively. Among the patients, 44 had central recurrences, two had in-field recurrences, one had marginal recurrence occurred, 11 had distant recurrences, and three had subependymal recurrences. Five patients had multiple recurrence patterns. Compared to the EORTC protocol, target delineation that excludes the adjacent T2/FLAIR hyperintensity area reduces the brain volume exposed to high-dose radiation (P = 0.000) without an increased risk of marginal recurrence. Therefore, it is worthwhile to conduct a clinical trial investigating the feasibility of intentionally not including the T2/FLAIR hyperintensity region outside of the GTV.
放射治疗是胶质母细胞瘤（GBM）的重要治疗方法，但关于GBM放射治疗的靶区勾画尚无共识。放射治疗肿瘤学组（RTOG）和欧洲癌症研究与治疗组织（EORTC）各有自己的规则。我们中心根据之前的研究采用了一种靶区体积勾画方案。本研究聚焦于靶区勾画未特意纳入大体肿瘤体积（GTV）外T2/液体衰减反转恢复（FLAIR）高信号区的GBM患者的复发模式。我们前瞻性收集了162例GBM病例，并回顾性分析了55例复发性GBM患者的临床数据及连续动态磁共振成像（MRI）。所有患者均接受了同步放化疗及替莫唑胺（TMZ）治疗。我们定义的GTV包括术后T1加权MRI增强区及切除腔。临床靶区体积1（CTV1）和CTV2分别定义为边缘外放1 cm和2 cm的GTV。计划靶区体积1（PTV1）和PTV2分别定义为CTV1和CTV2外加3 mm的边缘，处方剂量分别为60 Gy和54 Gy。将首次复发时的增强T1加权MRI引入Varian Eclipse放射治疗计划系统，并与原始计划计算机断层扫描（CT）图像融合以确定复发模式。中位随访时间为15.8个月。中位总生存期（OS）和无进展生存期（PFS）分别为17.7个月和7.0个月。患者中，44例为中心复发，2例为野内复发，1例为边缘复发，11例为远处复发，3例为室管膜下复发。5例患者有多种复发模式。与EORTC方案相比，排除相邻T2/FLAIR高信号区的靶区勾画可减少接受高剂量辐射的脑体积（P = 0.000），且边缘复发风险未增加。因此，开展一项临床试验研究特意不纳入GTV外T2/FLAIR高信号区的可行性是值得的。
