Department of Radiation Oncology, University of Pittsburgh Medical Center Hillman Cancer Center, Pittsburgh, Pennsylvania.
Department of Neurosurgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
Int J Radiat Oncol Biol Phys. 2018 Jul 1;101(3):602-609. doi: 10.1016/j.ijrobp.2018.02.035. Epub 2018 Mar 6.
To document the 5- and 10-year rates of late toxicity and vertebral compression fracture (VCF) in long-term survivors after stereotactic radiosurgery for spine metastases.
A retrospective review was performed on 562 patients treated with SRS for spine metastases between April 2001 and July 2011. Selecting those with at least 5-year survival after SRS, included were 43 patients who collectively underwent 84 treatments at 54 spine sites. Most were treated with single-fraction stereotactic radiosurgery to a median dose of 16 Gy (range, 12-24 Gy), and 56% of sites had received prior external beam radiation therapy. Late toxicities and VCFs occurring in the absence of tumor progression were recorded. Binary logistic regression was used to identify predictors of late complications.
Nine patients (17% of treatment sites) developed grade ≥2 late toxicities at a median time of 12.8 months (range, 4.2-59.0 months). Actuarial 5- and 10-year rates of grade ≥2 late toxicity were 17% and 17%, respectively. On multivariate analysis, only cumulative biologically effective dose (BED) > 200 Gy (or EQD2 [2-Gy equivalent dose calculated using an α/β ratio of 2] > 130 Gy) was associated with grade ≥2 late toxicity (P = .036). Maximum point BED > 110 Gy (or EQD2 > 70 Gy) to spinal cord or cauda equina was associated with grade ≥2 late neuropathy (P = .017). Nine VCFs (18%) occurred at a median time of 10.2 months (range, 3.2-57.2 months), with 5- and 10-year VCF rates of 17% and 17%, respectively.
Stereotactic radiosurgery for primary treatment and reirradiation of spinal metastases is associated with a moderate risk of late toxicity with 10-year follow-up. Risk of late toxicity significantly increases with cumulative BED > 200 Gy and spinal cord or cauda equina point BED > 110 Gy. Patients remain at moderate risk of VCF up to 5 years after treatment, with a plateau in incidence thereafter up to 10 years.
记录脊柱转移立体定向放射外科治疗后长期生存患者的 5 年和 10 年晚期毒性和椎体压缩性骨折（VCF）的发生率。
对 2001 年 4 月至 2011 年 7 月期间接受 SRS 治疗的 562 例脊柱转移瘤患者进行回顾性分析。选择 SRS 后至少生存 5 年的患者，共有 43 例患者在 54 个脊柱部位接受了 84 次治疗。大多数患者采用单次分割立体定向放射外科治疗，中位剂量为 16Gy（范围 12-24Gy），56%的部位接受过外照射放疗。记录无肿瘤进展时发生的晚期毒性和 VCF。采用二元逻辑回归分析确定晚期并发症的预测因素。
9 例患者（治疗部位的 17%）在中位时间 12.8 个月（范围 4.2-59.0 个月）时出现≥2 级晚期毒性。5 年和 10 年的≥2 级晚期毒性发生率分别为 17%和 17%。多变量分析显示，只有累积生物有效剂量（BED）>200Gy（或等效剂量 2-Gy 计算采用 α/β 比为 2 时的 EQD2>130Gy）与≥2 级晚期毒性相关（P=0.036）。脊髓或马尾的最大点 BED>110Gy（或 EQD2>70Gy）与≥2 级迟发性神经病相关（P=0.017）。9 例 VCF（18%）发生在中位时间 10.2 个月（范围 3.2-57.2 个月），5 年和 10 年的 VCF 发生率分别为 17%和 17%。
对于原发性治疗和脊柱转移再放疗，立体定向放射外科治疗后晚期毒性的风险中等，10 年随访时风险仍较高。累积 BED>200Gy 和脊髓或马尾点 BED>110Gy 与晚期毒性风险显著增加相关。治疗后 5 年内患者仍处于 VCF 的中度风险，此后直至 10 年风险呈平台期。
