Intensity modulated stereotactic body radiation therapy for single or multiple vertebral metastases with spinal cord compression.
PURPOSE
The purpose of this study was to evaluate the efficacy and toxicity of intensity modulated radiation therapy with simultaneous integrated boost (SIB-IMRT) for single or multiple vertebral metastases (VM) with spinal cord compression using tomotherapy.


METHODS AND MATERIALS
Thirty patients with 40 VM were treated with SIB-IMRT as initial radiation therapy. Either 40 Gy in 8 fractions or 48 Gy in 16 fractions was prescribed depending on the Katagiri prognostic index. The radiation doses to the spinal cord and other risk organs were reduced to tolerance levels using intensity modulation. One to 4 lesions in consecutive vertebrae were treated in 1 course of SIB-IMRT. Radiologic and physical examinations were performed at 1-3 month intervals after SIB-IMRT. The Barthel index (BI) and numerical rating scale (NRS) were used to evaluate activities of daily living (ADL) and pain status, respectively.


RESULTS
The median follow-up period was 8 months. The NRS significantly dropped at 1 month after SIB-IMRT (P < .0001) and the effect continued for over 2 months. No significant BI decrease was observed at 2 months after SIB-IMRT (P = .7). The 1-year local control rate was 84% (95% confidence interval, 70%-100%). No grade≥2 neurologic toxicity resulting from SIB-IMRT was observed.


CONCLUSIONS
SIB-IMRT could be successfully applied to VM with spinal cord compression in up to 4 consecutive vertebrae. Good ADL preservation and pain control were achieved with acceptable toxicity.