Department of Neurosurgery, University of Virginia Health Sciences Center, Box 800212, Charlottesville, VA 22902, USA.
Neurosurgery. 2010 Jan;66(1):208-17. doi: 10.1227/01.NEU.0000359318.90478.69.
This study evaluates the tumor histopathology and clinical characteristics of patients who underwent resection of their brain metastasis after failed gamma knife radiosurgery.
This study was a retrospective review from a prospective database. A total of 1200 brain metastases in 912 patients were treated by gamma knife radiosurgery during a 7-year period. Fifteen patients (1.6% of patients, 1.2% of all brain metastases) underwent resective surgery for either presumed tumor progression (6 patients) or worsening neurological symptoms associated with increased mass effect (9 patients). Radiographic imaging, radiosurgical and surgical treatment parameters, histopathological findings, and long-term outcomes were reviewed for all patients.
The mean age at the time of radiosurgery was 57 years (age range, 32-65 years). Initial pathological diagnoses included metastatic non-small cell lung carcinoma in 8 patients (53%), melanoma in 4 patients (27%), renal cell carcinoma in 2 patients (13%), and squamous cell carcinoma of the tongue in 1 patient (7%). The mean time interval between radiosurgery and surgical extirpation was 8.5 months (range, 3 weeks to 34 months). The mean treatment volume for the resected lesion at the time of radiosurgery was 4.4 cm(3) (range, 0.6-8.4 cm(3)). The mean dose to the tumor margin was 21Gy (range, 18-24 Gy). In addition to the 15 tumors that were eventually resected, a total of 32 other metastases were treated synchronously, with a 78% control rate. The mean volume immediately before surgery for the 15 resected lesions was 7.5 cm(3) (range, 3.8-10.2 cm(3)). Histological findings after radiosurgery varied from case to case and included viable tumor, necrotic tumor, vascular hyalinization, hemosiderin-laden macrophages, reactive gliosis in surrounding brain tissue, and an elevated MIB-1 proliferation index in cases with viable tumor. The mean survival for patients in whom viable tumor was identified (9.4 months) was significantly lower than that of patients in whom only necrosis was seen (15.1 months; Fisher's exact test, P < 0.05).
Radiation necrosis and tumor radioresistance are the most common causes precipitating a need for surgical resection after radiosurgery in patients with brain metastasis.
本研究评估了伽玛刀放射外科治疗后脑转移瘤切除患者的肿瘤组织病理学和临床特征。
本研究为回顾性研究，来自一个前瞻性数据库。7 年间，对 912 例患者的 1200 个脑转移瘤进行了伽玛刀放射外科治疗。15 例患者（占患者的 1.6%，占所有脑转移瘤的 1.2%）因疑似肿瘤进展（6 例）或与肿块效应增加相关的神经症状恶化（9 例）而行切除术。对所有患者的影像学、放射外科和手术治疗参数、组织病理学发现和长期结果进行了回顾。
放射外科治疗时的平均年龄为 57 岁（年龄范围为 32-65 岁）。初始病理诊断包括：非小细胞肺癌 8 例（53%）、黑色素瘤 4 例（27%）、肾细胞癌 2 例（13%）、舌鳞状细胞癌 1 例（7%）。放射外科治疗与手术切除之间的平均时间间隔为 8.5 个月（范围为 3 周至 34 个月）。放射外科治疗时切除病灶的平均治疗体积为 4.4cm3（范围为 0.6-8.4cm3）。肿瘤边缘的平均剂量为 21Gy（范围为 18-24Gy）。除最终切除的 15 个肿瘤外，还同步治疗了总共 32 个其他转移灶，控制率为 78%。术前 15 个切除病灶的平均体积为 7.5cm3（范围为 3.8-10.2cm3）。放射外科治疗后的组织学发现因病例而异，包括存活肿瘤、坏死肿瘤、血管玻璃样变、含铁血黄素巨噬细胞、周围脑组织反应性神经胶质增生和有存活肿瘤的病例中升高的 MIB-1 增殖指数。在有存活肿瘤的患者中（9.4 个月），平均生存期明显低于只有坏死的患者（15.1 个月；Fisher 确切检验，P<0.05）。
在脑转移瘤患者中，放射外科治疗后需要手术切除的最常见原因是放射性坏死和肿瘤放射抵抗。
