The benefits and pitfalls of ipsilateral radiotherapy in carcinoma of the tonsillar region.

PURPOSE: Ipsilateral techniques designed to restrict treatment to the primary tumor and neck on the same side have been used in selected cases of cases of carcinoma of the tonsillar region at our institution for many years. The primary purpose of this study is to evaluate the risk of failure in the opposite neck in cases selected for unilateral radiotherapy over a 21-year period.

METHODS AND MATERIALS: Ipsilateral radiotherapy techniques were used in 228 of 642 patients with carcinoma of the tonsillar region from 1970 to 1991. Local control, regional lymph-node control (including contralateral failure), and survival were calculated for different degrees of tumor extent treated with these techniques.

RESULTS: Mean follow-up was 7 years. Cases tended to be T1 and T2, with N0 disease. The 3-year actuarial local control rate was 77% and cause-specific survival was 76%. Opposite neck failure was seen in 8 patients (crude rate of 3.5%). In the earlier period of the study, primary coverage was problematic in a proportion of cases and resulted in higher rates of local failure.

CONCLUSION: Appropriately selected cases of carcinoma of the tonsil show minimal risk of failure in the opposite neck with ipsilateral techniques. Patients should undergo computed tomography planning to ensure adequate target coverage.