Clinical results of retreatment of vertebral bone metastases by stereotactic conformal radiotherapy and intensity-modulated radiotherapy

Purpose: Reirradiation of spinal tumors is limited by the tolerance of the spinal cord. We evaluated local control, pain relief, neurologic improvement, side effects, and survival rates after fractionated conformal radiotherapy (FCRT) and intensity-modulated RT (IMRT) of recurrent spinal metastases. Methods and Materials: Eighteen patients with 19 radiologic manifestations were retreated for recurrent spinal metastases using FCRT (n=5) or IMRT (n=14). All patients had previously undergone conventional RT (median dose 38 Gy). The indication for reirradiation was tumor progression associated with pain (n=16) or neurologic symptoms (n=12). The median time to recurrence was 17.7 months. The median total dose for reirradiation was 39.6 Gy. Results: The overall local control rate was 94.7% after a median follow-up of 12.3 months. Of 16 patients with pain, 13 experienced significant relief after reirradiation. Neurologic improvement was obtained in 5 of 12 patients. Tumor size remained unchanged in 84.2%. A partial response was seen in 2 of 19 patients. One patient had local tumor progression 9.5 months after reirradiation. Six patients received chemotherapy after reirradiation because of progressive distant metastases. Twelve patients died 10.5 months median after reirradiation. No clinically significant late toxicity was seen after FCRT or IMRT. Conclusion: These data demonstrate that FCRT and IMRT are effective and safe in recurrent spinal tumors and can be offered to patients to achieve local control, as well as pain relief