Bishop Andrew J, Tao Randa, Guadagnolo B Ashleigh, Allen Pamela K, Rebueno Neal C, Wang Xin A, Amini Behrang, Tatsui Claudio E, Rhines Laurence D, Li Jing, Chang Eric L, Brown Paul D, Ghia Amol J
Departments of 1 Radiation Oncology.
Radiation Dosimetry.
J Neurosurg Spine. 2017 Sep;27(3):303-311. doi: 10.3171/2017.1.SPINE161045. Epub 2017 Jun 23.
OBJECTIVE Given the relatively lower radiosensitivity of sarcomas and the locally infiltrative patterns of spread, the authors sought to investigate spine stereotactic radiosurgery (SSRS) outcomes for metastatic sarcomas and to analyze patterns of failure. METHODS The records of 48 patients with 66 sarcoma spinal metastases consecutively treated with SSRS between 2002 and 2013 were reviewed. The Kaplan-Meier method was used to estimate rates of overall survival (OS) and local control (LC). Local recurrences were categorized as occurring infield (within the 95% isodose line [IDL]), marginally (between the 20% and 95% IDLs), or out of field. RESULTS Median follow-up time was 19 months (range 1-121 months), and median age was 53 years (range 17-85 years). The most commonly treated histology was leiomyosarcoma (42%). Approximately two-thirds of the patients were treated with definitive SSRS (44 [67%]) versus postoperatively (22 [33%]). The actuarial 1-year OS and LC rates were 67% and 81%, respectively. Eighteen patients had a local relapse, which was more significantly associated with postoperative SSRS (p = 0.04). On multivariate modeling, receipt of postoperative SSRS neared significance for poorer LC (p = 0.06, subhazard ratio [SHR] 2.33), while only 2 covariates emerged as significantly correlated with LC: 1) biological equivalent dose (BED) > 48 Gy (vs BED ≤ 48 Gy, p = 0.006, SHR 0.21) and 2) single vertebral body involvement (vs multiple bodies, p = 0.03, SHR 0.27). Of the 18 local recurrences, 14 (78%) occurred at the margin, and while the majority of these cases relapsed within the epidural space, 4 relapsed within the paraspinal soft tissue. In addition, 1 relapse occurred out of field. Finally, the most common acute toxicity was fatigue (15 cases), with few late toxicities (4 insufficiency fractures, 3 neuropathies). CONCLUSIONS For metastatic sarcomas, SSRS provides durable tumor control with minimal toxicity. High-dose single-fraction regimens offer optimal LC, and given the infiltrative nature of sarcomas, when paraspinal soft tissues are involved, larger treatment volumes may be warranted.
目的 鉴于肉瘤的放射敏感性相对较低且具有局部浸润性扩散模式，作者试图研究脊柱立体定向放射外科（SSRS）治疗转移性肉瘤的疗效并分析失败模式。方法 回顾了2002年至2013年间连续接受SSRS治疗的48例患者66处肉瘤脊柱转移灶的记录。采用Kaplan-Meier法估计总生存（OS）率和局部控制（LC）率。局部复发分为野内复发（在95%等剂量线[IDL]内）、边缘复发（在20%至95% IDL之间）或野外复发。结果 中位随访时间为19个月（范围1 - 121个月），中位年龄为53岁（范围17 - 85岁）。最常治疗的组织学类型是平滑肌肉瘤（42%）。约三分之二的患者接受了根治性SSRS治疗（44例[67%]），其余为术后治疗（22例[33%]）。精算的1年OS率和LC率分别为67%和81%。18例患者出现局部复发，这与术后SSRS治疗更显著相关（p = 0.04）。在多变量模型中，接受术后SSRS治疗对较差的LC接近显著相关（p = 0.06，亚风险比[SHR] 2.33），而只有2个协变量与LC显著相关：1）生物等效剂量（BED）> 48 Gy（对比BED≤48 Gy，p = 0.006，SHR 0.21）和2）单个椎体受累（对比多个椎体，p = 0.03，SHR 0.27）。在18例局部复发中，14例（78%）发生在边缘，虽然这些病例大多数在硬膜外间隙复发，但4例在椎旁软组织复发。此外，1例野外复发。最后，最常见的急性毒性是疲劳（15例），晚期毒性较少（4例不全骨折，3例神经病变）。结论 对于转移性肉瘤，SSRS能以最小的毒性提供持久的肿瘤控制。高剂量单次分割方案可提供最佳的LC，鉴于肉瘤的浸润性本质，当椎旁软组织受累时，可能需要更大的治疗体积。
