Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, ON, M4N3M5, Canada.
Division of Neurosurgery, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada.
J Neurooncol. 2021 Mar;152(1):173-182. doi: 10.1007/s11060-020-03691-6. Epub 2021 Jan 16.
The concept of a radioresistant (RR) phenotype has been challenged with use of stereotactic body radiotherapy (SBRT). We compared outcomes following SBRT to RR spinal metastases to a radiosensitive cohort.
Renal cell, melanoma, sarcoma, gastro-intestinal, and thyroid spinal metastases were identified as RR and prostate cancer (PCA) as radiosensitive. The primary endpoint was MRI-based local failure (LF). Secondary endpoints included overall survival (OS) and vertebral compression fracture (VCF).
From a prospectively maintained database of 1394 spinal segments in 605 patients treated with spine SBRT, 173 patients/395 RR spinal segments were compared to 94 patients/185 PCA segments. Most received 24-28 Gy in 2 fractions (68.9%) and median follow-up was 15.5 months (range, 1.4-84.2 months). 1- and 2-year LF rates were 19.2% and 22.4% for RR metastases, respectively, which were significantly greater (p < 0.001) than PCA (3.2% and 8.4%, respectively). Epidural disease (HR: 2.47, 95% CI 1.65-3.71, p < 0.001) and RR histology (HR: 2.41, 95% CI 1.45-3.99, p < 0.001) predicted for greater LF. Median OS was 17.4 and 61.0 months for RR and PCA cohorts, respectively. Lung/liver metastases, polymetastatic disease and epidural disease predicted for worse OS. 2-year VCF rates were ~ 13% in both cohorts. Coverage of the CTV V90 (clinical target volume receiving 90% of prescription dose) by ≥ 87% (HR: 2.32, 95% CI 1.29-4.18, p = 0.005), no prior spine radiotherapy (HR: 1.96, 95% CI 1.09-3.55, p = 0.025), and a greater Spinal Instability Neoplasia Score (p = 0.013) predicted for VCF.
Higher rates of LF were observed after spine SBRT in RR metastases. Optimization strategies include dose escalation and aggressive management of epidural disease.
立体定向体部放疗（SBRT）的应用对放射性抵抗（RR）表型的概念提出了挑战。我们将 RR 脊柱转移瘤与放射敏感队列的患者进行比较，以评估 SBRT 后的结果。
肾细胞癌、黑色素瘤、肉瘤、胃肠道和甲状腺脊柱转移瘤被定义为 RR，前列腺癌（PCA）为放射敏感。主要终点为 MRI 局部失败（LF）。次要终点包括总生存（OS）和椎体压缩性骨折（VCF）。
从 605 例接受脊柱 SBRT 治疗的 1394 个脊柱段的前瞻性数据库中，173 例患者/395 个 RR 脊柱段与 94 例患者/185 个 PCA 段进行了比较。大多数患者接受 24-28 Gy 的 2 个分割剂量（68.9%），中位随访时间为 15.5 个月（范围为 1.4-84.2 个月）。RR 转移瘤的 1 年和 2 年 LF 率分别为 19.2%和 22.4%，显著高于 PCA（分别为 3.2%和 8.4%）（p < 0.001）。硬膜外疾病（HR：2.47，95%CI 1.65-3.71，p < 0.001）和 RR 组织学（HR：2.41，95%CI 1.45-3.99，p < 0.001）是 LF 增加的预测因素。RR 和 PCA 队列的中位 OS 分别为 17.4 和 61.0 个月。肺/肝转移、多发性转移疾病和硬膜外疾病预测 OS 较差。两个队列的 2 年 VCF 发生率均约为 13%。CTV V90（接受处方剂量 90%的临床靶区）覆盖率≥87%（HR：2.32，95%CI 1.29-4.18，p = 0.005）、无既往脊柱放疗（HR：1.96，95%CI 1.09-3.55，p = 0.025）和更高的脊柱不稳定性肿瘤评分（p = 0.013）与 VCF 相关。
RR 脊柱转移瘤患者接受 SBRT 后 LF 发生率更高。优化策略包括剂量递增和积极治疗硬膜外疾病。
