Efficacy and safety of CT-guided (125)I seed implantation by coplanar template as a salvage therapy for vertebral metastases after failure of external beam radiation therapy: a retrospective study

PURPOSE: To evaluate the efficacy safety of computed tomography (CT)-guided (125)I seed implantation by coplanar template for vertebral metastases after failure of external beam radiation therapy (EBRT). MATERIAL AND METHODS: Retrospective analysis of the clinical outcomes of 58 patients with vertebral metastases after failure of EBRT, who underwent (125)I seed implantation as a salvage treatment with a CT-guided coplanar template-assisted technique from January 2015 to January 2017. RESULTS: The mean post-operative NRS score decreased significantly at T(4w) (3.5 ± 0.9, p<0.01), T(8w) (2.1 ± 0.9, p<0.01), T(12w) (1.5 ± 0.7, p< 0.01) and T(6m) (1.2 ± 0.6, p< 0.01) respectively. The local control rates after 3, 6, 9 and 12 months were 100% (58/58), 93.1% (54/58), 87.9% (51/58), and 81% (47/58), respectively. The median overall survival time was 18.52months (95% CI, 16.24-20.8), and 1- and 2-year survival rates were 81% (47/58) and 34.5% (20/58), respectively. By performing a paired t-test analysis, there was no significant difference in D90, V90, D100, V100, V150, V200, GTV volume, CI, EI and HI between preoperative and postoperative (p>0.05). CONCLUSIONS: (125)I seed implantation can be used as a salvage treatment for patients with vertebral metastases after failure of EBRT.