Chew Chia-Hui, Chen Jin-Cherng, Hung Shih-Kai, Wu Tsung-Hsien, Lee Moon-Sing, Chiou Wen-Yen, Chen Liang-Cheng, Lin Hon-Yi
Department of Radiation Oncology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.
Department of Neurosurgery, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.
Tzu Chi Med J. 2022 Jun 27;34(4):462-472. doi: 10.4103/tcmj.tcmj_260_21. eCollection 2022 Oct-Dec.
Accelerator-based stereotactic radiosurgery (SRS) is a noninvasive and effective treatment modality widely used for benign brain tumors. This study aims to report 20-year treatment outcomes in our institute.
From May 2001 to December 2020, 127 patients treated with LINAC-based single-fraction SRS for their benign brain lesions were included. A neurosurgeon and two radiation oncologists retrospectively reviewed all data. Computed tomography (CT) simulation was performed after head-frame fixation under local anesthesia. All planning CT images were co-registered and fused with gadolinium-enhanced magnetic resonance imaging taken within 3 months for lesions targeting and critical organs delineation. The marginal dose was prescribed at 60%-90% isodose lines, respectively, to cover ≥95% planning target volume. Outcome evaluations included clinical tumor control rate (TCR), defined as the need for salvage therapy, and radiological response, defined as no enlargement of >2 cm in the maximal diameter. Overall survival (OS) and adverse reaction (defined according to CTCAE 5.0) were also analyzed.
The present study included 76 female and 51 male patients for analysis. The median age was 59 years (range, 20-88 years). Their diagnoses were vestibular schwannoma (VS, = 54), nonvestibular cranial nerve schwannoma ( = 6), meningioma ( = 50), and pituitary adenoma ( = 17). Totally 136 lesions were treated in a single fraction, predominantly skull base tumors, accounting for 69.1%. Median and mean follow-up duration was 49 and 61 months (range, 1-214 months), Overall TCR was 92.9%. The 5-year disease-specific TCR for VS, nonvestibular schwannoma, meningioma, and pituitary adenoma were 97.4%, 91.7%, 93.8%, and 83.3%. Salvage therapy was indicated for eight patients at 4-110 months after SRS. Among symptomatic patients, post-SRS symptom(s) was improved, stable, and worse in 68.2%, 24.3%, and 3.6%, respectively. Radiological response rate for 111 evaluable patients was 94.6% (shrinkage, 28.8%; stable, 65.8%). OS was 96.1% without treatment-related mortality. One patient with post-SRS cranial nerve injury (0.8%, involving the trigeminal nerve, grade 2 toxicities). No grade 3-4 acute or late toxicity was found.
Our results suggested that LINAC-based SRS effectively controls tumor growth and tumor-related neurological symptoms for patients with benign brain tumors. SRS is less aggressive, associated with low neurological morbidity and no mortality. Continuous follow-up is indicated to conclude longer outcomes.
基于加速器的立体定向放射外科治疗（SRS）是一种广泛应用于良性脑肿瘤的非侵入性有效治疗方式。本研究旨在报告我院20年的治疗结果。
纳入2001年5月至2020年12月期间接受基于直线加速器的单次分割SRS治疗良性脑病变的127例患者。一名神经外科医生和两名放射肿瘤学家对所有数据进行了回顾性分析。在局部麻醉下头架固定后进行计算机断层扫描（CT）模拟。所有计划CT图像与3个月内采集的钆增强磁共振成像进行配准和融合，用于病变定位和关键器官勾画。边缘剂量分别规定在60%-90%等剂量线上，以覆盖≥95%的计划靶体积。结果评估包括临床肿瘤控制率（TCR），定义为是否需要挽救治疗，以及放射学反应，定义为最大直径增大不超过2 cm。还分析了总生存期（OS）和不良反应（根据CTCAE 5.0定义）。
本研究纳入76例女性和51例男性患者进行分析。中位年龄为59岁（范围20-88岁）。他们的诊断为前庭神经鞘瘤（VS，n = 54）、非前庭颅神经鞘瘤（n = 6）、脑膜瘤（n = 50）和垂体腺瘤（n = 17）。共136个病变接受单次分割治疗，主要为颅底肿瘤，占69.1%。中位和平均随访时间分别为49个月和61个月（范围1-214个月）。总体TCR为92.9%。VS、非前庭神经鞘瘤、脑膜瘤和垂体腺瘤的5年疾病特异性TCR分别为97.4%、91.7%、93.8%和83.3%。8例患者在SRS后4-110个月需要挽救治疗。在有症状的患者中，SRS后症状改善、稳定和恶化的分别占68.2%、24.3%和3.6%。111例可评估患者的放射学反应率为94.6%（缩小，28.8%；稳定，65.8%）。OS为96.1%，无治疗相关死亡。1例患者出现SRS后颅神经损伤（0.8%，累及三叉神经，2级毒性）。未发现3-4级急性或晚期毒性。
我们的结果表明，基于直线加速器的SRS能有效控制良性脑肿瘤患者的肿瘤生长和肿瘤相关神经症状。SRS侵袭性较小，神经发病率低且无死亡率。需要持续随访以得出更长时间的结果。
