Tumor volume as prognostic factor in chemoradiation for advanced head and neck cancer.

BACKGROUND Tumor volume is an important predictor of outcome in radiotherapy alone. Its significance in concomitant chemoradiation (CCRT) is much less clear. We analyzed the prognostic value of primary tumor volume for advanced head and neck squamous cell carcinoma (HNSCC) treated with CCRT. METHODS Three hundred sixty patients treated with definitive CCRT for advanced HNSCC were selected. The pretreatment MRI or CT scan was used to calculate the primary tumor volume. Median follow-up was 19.8 months. RESULTS The average primary tumor volume was 37.0 cm³ (range, 2.1-182.7 cm³; median, 28.7 cm³). Multivariate analysis showed a significant effect of tumor volume on local control. The hazard ratio for a local recurrence increased by 14% per 10 cm³ volume increase (95% CI, 8% to 21%). There was no significant independent effect of T and N status on local control. CONCLUSION For advanced HNSCC, tumor volume is more powerful for predicting outcome after CCRT than TNM status.