Freedom from local and regional failure of contralateral neck with ipsilateral neck radiotherapy for node-positive tonsil cancer: Updated results of an institutional clinical management approach

Summary Purpose To update the outcomes of an institutional clinical management approach using ipsilateral neck radiotherapy in the treatment of node-positive squamous cell carcinoma of the tonsil with a well-lateralized primary lesion. Methods and Materials Between August 2003 and April 2014, 61 consecutive patients with ipsilateral node-positive squamous cell carcinoma of the tonsil without involvement of the base of the tongue or midline soft palate were treated at a community hospital-based cancer center with radiotherapy to the primary site and ipsilateral neck. Overall survival, disease-free survival and freedom from contralateral failure were calculated. Results Median follow up was 37.2 months (range 4-121 months). Freedom from contralateral nodal failure at 5 years was 98% with one contralateral nodal failure noted. The patient underwent a salvage neck dissection and was treated with post-operative radiotherapy with no evidence of disease to date. 5-year overall survival (OS) was 92.4% and 5 year disease-free survival (DFS) was 86.7%. Conclusions This represents the single largest series reported from a community hospital-based cancer center in which lateralized tonsil cancers with N+ disease were treated with ipsilateral neck radiotherapy. In this carefully selected cohort of patients with well-lateralized tonsil cancers, the risk of contralateral nodal failure appears to be <5%, suggesting that prophylactic radiation of the contralateral neck may not be necessary. Future planned studies will focus on prospectively selecting subgroups of patients eligible for treatment de-intensification as survivorship issues in excellent prognosis HPV positive patients are increasingly becoming relevant.