Arjun Sahgal and Ameen Al-Omair, Princess Margaret Cancer Centre; Arjun Sahgal, Ameen Al-Omair, Marcelo Cunha, and Isabelle Thibault, Sunnybrook Health Sciences Centre; Eshetu G. Atenafu, University Health Network; Michael G. Fehlings, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada; Sam Chao, Ehsan H. Balagamwala, Lilyana Angelov, and John Suh, Cleveland Clinic, Cleveland, OH; Nicholas Boehling, Paul Brown, Laurence D. Rhines, and Eric Chang, MD Anderson Cancer Center, University of Texas, Houston, TX; and Eric Chang, University of Southern California, Los Angeles, CA.
J Clin Oncol. 2013 Sep 20;31(27):3426-31. doi: 10.1200/JCO.2013.50.1411. Epub 2013 Aug 19.
Vertebral compression fracture (VCF) is increasingly recognized as an adverse event after spine stereotactic body radiotherapy (SBRT). We report a multi-institutional study aimed at clarifying the risk and predictive factors associated with VCF.
A total of 252 patients with 410 spinal segments treated with SBRT were included. The primary outcome was the development of VCF (a new VCF or progression of a baseline VCF). In addition to various patient-, treatment-, and tumor-specific factors, the Spinal Instability Neoplastic Scoring (SINS) system was applied to determine predictive value.
The median follow-up was 11.5 months (range, 0.03 to 113 months). The median and mean overall survival rates were 16 and 26 months, respectively. We observed 57 fractures (57 of 410, 14%), with 47% (27 of 57) new fractures and 53% (30 of 57) fracture progression. The median time to VCF was 2.46 months (range, 0.03 to 43.01 months), and 65% occurred within the first 4 months. The 1- and 2-year cumulative incidences of fracture were 12.35% and 13.49%, respectively. Multivariable analysis identified dose per fraction (greatest risk for ≥ 24 Gy v 20 to 23 Gy v ≤ 19 Gy), in addition to three of the six original SINS criteria: baseline VCF, lytic tumor, and spinal deformity, as significant predictors of VCF.
Caution must be observed when treating with ≥ 20 Gy/fraction, in particular, for patients with lytic tumor, spinal misalignment, and a baseline VCF. Frequent short-term follow-up is required, as nearly two thirds of all VCF occurred within the first 4 months. We also conclude that SINS may have utility in predicting patients at high risk of SBRT-induced VCF.
脊柱立体定向体部放疗（SBRT）后，椎体压缩性骨折（VCF）越来越被认为是一种不良事件。我们报告了一项多机构研究，旨在阐明与 VCF 相关的风险和预测因素。
共纳入 252 例 410 个脊柱节段接受 SBRT 治疗的患者。主要结局是 VCF 的发生（新发 VCF 或基线 VCF 进展）。除了各种患者、治疗和肿瘤特异性因素外，还应用脊柱不稳定肿瘤评分（SINS）系统来确定预测价值。
中位随访时间为 11.5 个月（范围：0.03 至 113 个月）。中位和平均总生存率分别为 16 个月和 26 个月。我们观察到 57 例骨折（410 个中的 57 例，14%），其中 47%（27/57）为新发骨折，53%（30/57）为骨折进展。VCF 的中位时间为 2.46 个月（范围：0.03 至 43.01 个月），65%发生在第 1 至 4 个月内。1 年和 2 年的累积骨折发生率分别为 12.35%和 13.49%。多变量分析发现，每分次剂量（最大风险为≥24 Gy 比 20 至 23 Gy 比≤19 Gy），以及 SINS 的六个原始标准中的三个：基线 VCF、溶骨性肿瘤和脊柱畸形，是 VCF 的显著预测因素。
当以≥20 Gy/分次进行治疗时，特别是对于患有溶骨性肿瘤、脊柱错位和基线 VCF 的患者，必须谨慎。需要进行频繁的短期随访，因为几乎三分之二的 VCF 发生在第 1 至 4 个月内。我们还得出结论，SINS 可能有助于预测 SBRT 引起的 VCF 风险较高的患者。
