Dincer Neris, Zoto Mustafayev Teuta, Atahan Ceren, Gungor Gorkem, Ugurluer Gamze, Abacioglu Mehmet Ufuk, Ozyar Enis, Atalar Banu
Department of Radiation Oncology, Acıbadem MAA University School of Medicine, 34450, Istanbul, Turkey.
Department of Radiation Oncology, Acıbadem Maslak Hospital, Istanbul, Turkey.
Strahlenther Onkol. 2025 Apr 28. doi: 10.1007/s00066-025-02401-3.
Stereotactic body radiotherapy (SBRT) is associated with good local control and symptom relief in the management of spinal metastases. Delivery of ablative doses and re-irradiation is challenged by spinal cord toxicity. We hypothesized that lower spinal cord doses as well as better target coverage could be yielded with stereotactic magnetic resonance-guided adaptive radiotherapy (SMART).
Institutional records were reviewed to retrieve patients who received online MR-guided SBRT for spinal metastases. Each fraction was reviewed to determine the necessity of adaptive planning, to identify reasons for violations that required adaptive planning, and to assess the spinal cord dose. The study also evaluated how adaptive planning contributed to reducing spinal cord doses.
A total of 34 patients with 61 lesions were included. The treatment intent was definitive for 47 (77.1%), palliative for 12 (19.7%), and postoperative for two (3.3%) lesions. The median prescribed Biological Equivalent Dose (BED) was 51.3 Gy. Treatment plans often required adaptive adjustments (81.8%). Adaptive planning significantly improved target coverage (median PTV coverage 92.75% vs. 95%; p < 0.001) and reduced spinal cord D (median spinal cord D constraint: 7.3 Gy, median predicted spinal cord D: 7.76, and median adaptive spinal cord D 6.18; p < 0.001). Lesion-based median follow-up from irradiation was 7.5 months (range: 1-46 months). One-year LPFS was 94.3%. Six lesions progressed and none of the progressed lesions received a dose above the median BED of 51.3 Gy.
Herein we present our institutional experience with SMART for spinal bone metastases. According to our results, adaptive planning yields better target coverage as well as lower spinal cord doses compared to the predicted plan, which translates into a feasible method for delivering SBRT. Future prospective studies evaluating spinal SMART are awaited.
立体定向体部放疗（SBRT）在脊柱转移瘤的治疗中具有良好的局部控制效果和症状缓解作用。脊髓毒性对消融剂量的给予和再照射构成挑战。我们推测立体定向磁共振引导的自适应放疗（SMART）能够降低脊髓剂量并更好地覆盖靶区。
回顾机构记录以检索接受在线磁共振引导的SBRT治疗脊柱转移瘤的患者。对每个分次进行评估，以确定自适应计划的必要性，识别需要自适应计划的违规原因，并评估脊髓剂量。该研究还评估了自适应计划如何有助于降低脊髓剂量。
共纳入34例患者的61个病灶。治疗目的为根治性的有47个（77.1%），姑息性的有12个（19.7%），术后的有2个（3.3%）病灶。处方生物等效剂量（BED）的中位数为51.3 Gy。治疗计划常需要进行自适应调整（81.8%）。自适应计划显著改善了靶区覆盖（PTV覆盖中位数92.75%对95%；p <0.001）并降低了脊髓D（脊髓D约束中位数：7.3 Gy，预测脊髓D中位数：7.76，自适应脊髓D中位数6.18；p <0.001）。从放疗开始基于病灶的中位随访时间为7.5个月（范围：1 - 46个月）。1年局部无进展生存率为94.3%。6个病灶进展，且进展的病灶中没有一个接受的剂量高于51.3 Gy的BED中位数。
在此我们介绍我们机构使用SMART治疗脊柱骨转移瘤的经验。根据我们的结果，与预测计划相比，自适应计划能产生更好的靶区覆盖以及更低的脊髓剂量，这转化为一种可行的SBRT实施方法。期待未来评估脊柱SMART的前瞻性研究。
