Objectives: The objectives of this paper are to describe pain control, neurologic improvement, local tumor control, progression-free survival, and overall survival of spine SRS/SFRT patients, and to compare our outcomes with other studies on spine stereotactic radiotherapy for metastatic tumors.
Methods: A chart review of patients who underwent spine SRS/SFRT was done. Information was collected on patient age, sex, histology, site treated, pain relief, local control, neurologic function, prescription dose, and complications. Descriptive statistics, median local control rates, progression-free survival, and overall survival were calculated.
Results: Twenty eight SRS and 3 SFRT target volumes in 21 patients were studied. Eighteen underwent SRS and 3 underwent SFRT for metastasis from August 2012 to February 2016. Follow-up ranged from 4 to 41 months. Average dose was 16.6 ± 3.9 Gy. Spine SRS mean target volume was 31.1 cc (95% CI, 21.7-40.6 cc). Median overall survival after treatment was 16 months (95% CI, 9.7-22.3 months) and median progression-free survival was 13 months (95% CI, 8.4-17.6 months). Local control was 46%, 30%, and 15% at 6, 8, and 10 months, respectively. Average onset of pain relief is 4.9 days (95% CI, 0.8-8.9 days). One patient (5%) developed post SRS vertebral compression fracture.
Conclusion: SRS/SFRT is a safe and effective alternative to EBRT for the treatment of spine metastasis. Improvement in pain control and motor strength and incidence of adverse events are comparable with other studies. Local tumor control was lower in our series due to a lower mean prescribed dose.
Keywords: Spine metatases; cost; dose; local tumor control; stereotactic fractionated radiotherapy; stereotactic radiosurgery.