A prospective study of hippocampal-avoidance prophylactic cranial irradiation in small cell lung cancer patients with limited stage
Kong Yue1, Xie Tieming2, Shi Lei2, Du Fenglei1, Hu Xiao1, Gu Qing1, Wang Jin1, Fang Min1, Chen Mengyuan1, Xu Yujin1, Ma Honglian1, Chen Ming1, Chen Yuanyuan1
1 Department of Radiation Oncology, Cancer Hospital of the University of Chinese Academy of Science (Zhejiang Cancer Hospital), Institute of Cancer and Basic Medicine (IBMC), Chinese Academy of Sciences, Hangzhou 310022, China; 2 Department of Radiology,Cancer Hospital of the University of Chinese Academy of Science (Zhejiang Cancer Hospital), Institute of Cancer and Basic Medicine (IBMC), Chinese Academy of Sciences, Hangzhou 310022, China
Abstract：Objective To analyze the feasibility of hippocampal-avoidance (HA) prophylactic cranial irradiation (PCI) in small cell lung cancer patients (SCLC)(limited stage) after chemotherapy and thoracic radiation. Methods From June 2016 to March 2019, 40 eligible SCLC patients were recruited and randomly divided into the routine PCI (n=22) and hippocampal-avoidance PCI (HA-PCI) groups (n=18). The HA zone was contoured according to the criteria of RTOG 0933. Volumetric-modulated arc therapy (VMAT) was adopted in the HA-PCI group. After radiotherapy, Hopkins verbal learning test (HVLT) and MRI were performed. Results The average hippocampus volume was (4.01±1.57) cm3, the average HA volume was (20.13±4.14) cm3, HA D100% was (7.19±0.38) Gy and HA Dmax was (14.38±1.18) Gy. During HVLT, 1-month-after-PCI vs. before-PCI (trial3, trial4, learning, percent retained), 1-month-after-PCI vs. after-PCI (trial3, learning), HA-PCI cohort showed advantages over PCI in HVLT scores. The average follow-up time was (17.00±8.47) months. Two patients with brain metastases which were out of the HAZ received routine PCI. Conclusions PCI using VMAT technology to protect hippocampus is feasible in dosimetry. The test results indicate that the protective effect of hippocampus protection on memory is worthy of further promotion in clinical practice.
Kong Yue,Xie Tieming,Shi Lei et al. A prospective study of hippocampal-avoidance prophylactic cranial irradiation in small cell lung cancer patients with limited stage[J]. Chinese Journal of Radiation Oncology, 2020, 29(8): 629-632.
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