THE DOSIMETRIC ANALYSIS AND CLINICAL OUTCOMES OF CONTIGUOUS VERTEBRAE STEREOTACTIC BODY RADIOTHERAPY IN OLIGOMETASTATIC PATIENTS

Birhan DEMİRHAN, Ayşenur ELMALI, Yemliha DÖLEK, Recep BOZCA, Ozan Cem GÜLER, Hüseyin Cem ÖNAL

Turkish Journal of Oncology - 2026;41(2):137-145

Department of Radiation Oncology, İskenderun Gelişim Hospital, Hatay-Türkiye

 

OBJECTIVE To evaluate the dosimetric characteristics and clinical outcomes of metastasis-directed therapy (MDT) using stereotactic body radiotherapy (SBRT) for contiguous vertebral metastases in patients with oligometastatic disease. METHODS Clinical and dosimetric data from 58 patients (64 lesions) treated between December 2012 and December 2020 were retrospectively reviewed. All patients had <=5 metastases at diagnosis or during follow-up and were treated with single-fraction SBRT. Primary endpoints were local control (LC) and progression-free survival (PFS), and the secondary endpoint was overall survival (OS). RESULTS Mean clinical tumor volume was 27.55 cc, mean spinal cord volume was 4.41 cc, and the mean maximum spinal cord dose was 11.68 Gy. Median age was 54 years and median follow-up was 12 months; 83% of patients had died at last follow-up. Two-year OS and PFS rates were 65% and 45%, while 1- and 2-year LC rates were 81% and 70%. Local recurrence occurred in 17% of patients at a median of 6 months. Recurrence within 12 months was associated with worse survival (p=0.013). No grade >=3 toxicity was observed. CONCLUSION Single-fraction SBRT for contiguous vertebral metastases is feasible and provides acceptable local control with low toxicity; however, distant progression and recurrence warrant further studies of combined systemic therapy.