Outcomes utilizing intensity-modulated radiotherapy in oropharyngeal cancers: Tonsils versus base of tongue.

Abstract

The purpose of this study was to present the outcomes of oropharyngeal cancers treated with intensity-modulated radiotherapy (IMRT) especially the differences between tonsillar and base of tongue (BOT) primaries. Retrospective analysis of 124 patients with biopsy proven squamous cell carcinomas of the oropharynx, treated with IMRT. Human papillomavirus (HPV) association correlated with improvement in survivals in both tonsillar and BOT primaries. At the 2-year median follow-up, the cumulative incidences of locoregional recurrences were 8% in both the tonsil and BOT groups (P = .76) but the distant metastases were 8% in the tonsil group versus 26% in the BOT group (P = .009). Thirty percent of tonsil primaries has ≥N2c neck disease as compared to 54% of BOT. Incidence of distant metastases increases with advanced nodal classification, especially >N2c. Even though the locoregional controls are excellent with IMRT and chemotherapy, these patients continue to fail distantly, particularly significant for the BOT group and for nodal stage >N2c.