Ito Kei, Nihei Keiji, Shimizuguchi Takuya, Ogawa Hiroaki, Furuya Tomohisa, Sugita Shurei, Hozumi Takahiro, Karasawa Katsuyuki
1Division of Radiation Oncology, Department of Radiology, and.
3Department of Radiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
J Neurosurg Spine. 2018 Sep;29(3):332-338. doi: 10.3171/2018.1.SPINE171155. Epub 2018 Jun 15.
OBJECTIVE This study aimed to clarify the outcomes of postoperative re-irradiation using stereotactic body radiotherapy (SBRT) for metastatic epidural spinal cord compression (MESCC) in the authors' institution and to identify factors correlated with local control. METHODS Cases in which patients with previously irradiated MESCC underwent decompression surgery followed by spine SBRT as re-irradiation between April 2013 and May 2017 were retrospectively reviewed. The surgical procedures were mainly performed by the posterior approach and included decompression and fixation. The prescribed dose for spine SBRT was 24 Gy in 2 fractions. The primary outcome was local control, which was defined as elimination, shrinkage, or no change of the tumor on CT or MRI obtained approximately every 3 months after SBRT. In addition, various patient-, treatment-, and tumor-specific factors were evaluated to determine their predictive value for local control. RESULTS Twenty-eight cases were identified in the authors' institutional databases as meeting the inclusion criteria. The histology of the primary disease was thyroid cancer in 7 cases, lung cancer in 6, renal cancer in 3, colorectal cancer in 3, and other cancers in 9. The most common previous radiation dose was 30 Gy in 10 fractions (15 cases). The mean interval since the most recent irradiation was 16 months (range 5-132 months). The median duration of follow-up after SBRT was 13 months (range 4-38 months). The 1-year local control rate was 70%. In the analysis of factors related to local control, Bilsky grade, number of vertebral levels in the treatment target, the interval between the latest radiotherapy and SBRT, recursive partitioning analysis (RPA), the prognostic index for spinal metastases (PRISM), and the revised Tokuhashi score were not significantly correlated with local control. The favorable group classified by the Rades prognostic score achieved a significantly higher 1-year local control rate than the unfavorable group (1-year local control rate: 100% vs 33%; p < 0.01). Radiation-induced myelopathy and vertebral compression fracture were observed in 1 and 3 patients, respectively. No other grade 3 or greater toxicities were encountered. CONCLUSIONS The results indicate that spine SBRT as postoperative re-irradiation was effective, and it was especially useful for patients classified as having a good survival prognosis according to the Rades score.
目的 本研究旨在阐明在作者所在机构中，使用立体定向体部放疗（SBRT）对转移性硬膜外脊髓压迫症（MESCC）进行术后再照射的结果，并确定与局部控制相关的因素。方法 回顾性分析2013年4月至2017年5月期间，先前接受过放疗的MESCC患者在减压手术后接受脊柱SBRT作为再照射的病例。手术主要通过后路进行，包括减压和固定。脊柱SBRT的处方剂量为24 Gy，分2次照射。主要结局为局部控制，定义为在SBRT后大约每3个月进行的CT或MRI检查中，肿瘤消除、缩小或无变化。此外，评估了各种患者、治疗和肿瘤特异性因素，以确定它们对局部控制的预测价值。结果 在作者所在机构的数据库中，有28例病例符合纳入标准。原发疾病的组织学类型为甲状腺癌7例、肺癌6例、肾癌3例、结直肠癌3例、其他癌症9例。既往最常见的放疗剂量为30 Gy，分10次照射（15例）。自最近一次放疗后的平均间隔时间为16个月（范围5 - 132个月）。SBRT后的中位随访时间为13个月（范围4 - 38个月）。1年局部控制率为70%。在与局部控制相关因素的分析中，Bilsky分级、治疗靶区的椎体节段数、最近一次放疗与SBRT之间的间隔时间、递归分区分析（RPA）、脊柱转移预后指数（PRISM）和修订的Tokuhashi评分与局部控制均无显著相关性。根据Rades预后评分分类的良好组1年局部控制率显著高于不良组（1年局部控制率：100%对33%；p < 0.01）。分别有1例和3例患者出现放射性脊髓病和椎体压缩骨折。未遇到其他3级或更高级别的毒性反应。结论 结果表明，脊柱SBRT作为术后再照射是有效的，对于根据Rades评分分类为生存预后良好的患者尤其有用。
