Abstract：
BACKGROUND: Stereotactic ablative body radiotherapy (SABR) is a highly conformal technique utilising a high dose per fraction commonly employed in the re-treatment of spinal metastases. This study sought to determine the safety and efficacy of re-irradiation with SABR to previously treated spinal metastases.
METHODS: This was a retrospective analysis of patients at three Australian centres who have undergone spinal SABR after previous spinal radiotherapy to the same or immediately adjacent vertebral level. Efficacy was determined in terms of rates of local control, while safety was characterised by rates of serious complications.
RESULTS: Thirty-three spinal segments were evaluated from 32 patients. Median follow-up for all patients was 2.6 years, and median overall survival was 4.3 years. Eleven of 33 (33.3%) treated spinal segments had local progression, with a local control rate at 12 months of 71.4% (95% C.I. 55.2%-92.4%). Four patients (16.7%) went on to develop cauda equina or spinal cord compression. Thirteen out of 32 patients (40.6%) experienced acute toxicity, of which 12 were grade 2 or less. Five out of 30 spinal (16.7%) segments with follow-up imaging had a radiation-induced vertebral compression fracture. There was one case of radiation myelitis which occurred in a patient who had mediastinal radiotherapy with a treatment field which overlapped their prior spinal radiation.
CONCLUSIONS: The patients in this study experienced long median survival, durable tumour control and high rates of freedom from long-term sequelae of treatment. These results support the use of SABR in patients who progress in the spine despite previous radiotherapy.
METHODS: This was a retrospective analysis of patients at three Australian centres who have undergone spinal SABR after previous spinal radiotherapy to the same or immediately adjacent vertebral level. Efficacy was determined in terms of rates of local control, while safety was characterised by rates of serious complications.
RESULTS: Thirty-three spinal segments were evaluated from 32 patients. Median follow-up for all patients was 2.6 years, and median overall survival was 4.3 years. Eleven of 33 (33.3%) treated spinal segments had local progression, with a local control rate at 12 months of 71.4% (95% C.I. 55.2%-92.4%). Four patients (16.7%) went on to develop cauda equina or spinal cord compression. Thirteen out of 32 patients (40.6%) experienced acute toxicity, of which 12 were grade 2 or less. Five out of 30 spinal (16.7%) segments with follow-up imaging had a radiation-induced vertebral compression fracture. There was one case of radiation myelitis which occurred in a patient who had mediastinal radiotherapy with a treatment field which overlapped their prior spinal radiation.
CONCLUSIONS: The patients in this study experienced long median survival, durable tumour control and high rates of freedom from long-term sequelae of treatment. These results support the use of SABR in patients who progress in the spine despite previous radiotherapy.
摘要：
背景：立体定向消融全身放疗（SABR）是一种高度适形的技术，通常用于脊柱转移瘤的再治疗。这项研究旨在确定SABR对先前治疗过的脊柱转移瘤进行再照射的安全性和有效性。
方法：这是一项对澳大利亚三个中心的患者的回顾性分析，这些患者在先前脊柱放疗后接受了相同或紧邻的椎骨水平的脊柱SABR。根据局部控制率确定疗效，而安全性的特点是严重并发症的发生率。
结果：对32例患者的33个脊柱节段进行了评估。所有患者的中位随访时间为2.6年，中位总生存期为4.3年.33个（33.3％）治疗的脊柱节段中有11个局部进展，12个月的局部控制率为71.4%（95%C.I.55.2%-92.4%）。四名患者（16.7％）继续发展为马尾神经或脊髓压迫。32例患者中有13例（40.6%）出现急性毒性，其中12个为2级或以下。在随访成像的30个脊柱节段中，有5个（16.7％）患有放射性椎体压缩性骨折。有一例放射性脊髓炎发生在纵隔放疗的患者中，其治疗区域与先前的脊柱放射重叠。
结论：本研究的患者中位生存期长，持久的肿瘤控制和长期治疗后遗症的高发生率。这些结果支持SABR在尽管先前进行过放射治疗但仍在脊柱进展的患者中使用。
方法：这是一项对澳大利亚三个中心的患者的回顾性分析，这些患者在先前脊柱放疗后接受了相同或紧邻的椎骨水平的脊柱SABR。根据局部控制率确定疗效，而安全性的特点是严重并发症的发生率。
结果：对32例患者的33个脊柱节段进行了评估。所有患者的中位随访时间为2.6年，中位总生存期为4.3年.33个（33.3％）治疗的脊柱节段中有11个局部进展，12个月的局部控制率为71.4%（95%C.I.55.2%-92.4%）。四名患者（16.7％）继续发展为马尾神经或脊髓压迫。32例患者中有13例（40.6%）出现急性毒性，其中12个为2级或以下。在随访成像的30个脊柱节段中，有5个（16.7％）患有放射性椎体压缩性骨折。有一例放射性脊髓炎发生在纵隔放疗的患者中，其治疗区域与先前的脊柱放射重叠。
结论：本研究的患者中位生存期长，持久的肿瘤控制和长期治疗后遗症的高发生率。这些结果支持SABR在尽管先前进行过放射治疗但仍在脊柱进展的患者中使用。
