High-dose-rate brachytherapy in early oral cancer with close or positive margins.

PURPOSE: Retrospective evaluation of high-dose-rate brachytherapy (HDR BT) in early oral cancer and factors influencing tumor control.

METHODS AND MATERIALS: A total of 30 patients with T1-T3N0 tongue and floor of mouth cancer were treated with tumor excision±elective neck dissection and HDR BT 18×3 Gy b.i.d. The Kaplan-Meier model was used for survival analyses, and the log-rank test and Cox regression analyses were used to evaluate the influence of T-stage, histologic grade, resection margin, depth of invasion, and vascular endothelial growth factor (VEGF) intensity on local control (LC), nodal control (NC), disease-free survival (DFS), and overall survival (OS). Median followup was 40 months (6-145).

RESULTS

Actuarial 3-year LC, NC, DFS, DFS after salvage treatment, and OS were 85.4%, 69.2%, 65.4%, 75.6%, and 73.0%, respectively. The log-rank test and univariate Cox regression analysis revealed the following correlations, namely tumor grade correlated with LC, DFS, and OS; T-stage with NC and DFS; depth of invasion and VEGF intensity with NC, DFS, and OS. Associations detected on the multivariate analysis were as follows: tumor grade with LC, depth of invasion with NC, depth of invasion and tumor grade with DFS, and VEGF intensity with DFS after salvage treatment. Only one case of osteoradionecrosis and two cases of soft tissue necrosis occurred.

CONSLUSION: The HDR BT 18×3 Gy b.i.d. is a safe treatment of early oral cancer with a good LC. The T-stage, tumor grade, depth of invasion, and intensity of VEGF were significant predictors of locoregional control.