Regional control is preserved after dose de-escalated radiotherapy to involved lymph nodes in HPV positive XXXX .

@entity1 @entity5 @entity957 @entity900 @entity3
OBJECTIVES: To analyze a cohort of @entity1 with HPV positive, @entity957 ( @entity957 ) treated with lower radiation dose to clinically involved lymph nodes. MATERIALS AND METHODS: We retrospectively identified @entity1 with HPV positive, @entity957 treated with definitive chemoradiotherapy (70-74.4Gy) to the primary site and, since a post-radiation neck dissection was planned, 54Gy to the involved nodal areas. Neck dissection was ultimately omitted in all cases due to complete response. All @entity1 were treated with a 3 field approach with sequential boost plans. Composite plans were generated retrospectively and primary @entity5 and lymph node GTVs were contoured and nodes were expanded by 5mm to form a CTV. Mean dose, dose to 95% (D95) and dose to 99% (D99) were determined. RESULTS: Fifty @entity1 treated from 2008 to 2010 with 113 involved nodes were identified. The median age was 57years, and 6%, 46%, and 48% were current, former, and never smokers. Ninety percent of @entity1 received concurrent @entity900 based chemotherapy. Median D95 and D99 to involved nodes were 59.8Gy and 55.9Gy respectively. At a median follow up of 54.1months, two @entity1 developed nodal failure and four developed @entity3 . Five year loco-regional control, disease free survival and overall survival were 96%, 81% and 86% respectively. CONCLUSION: In this exploratory analysis, regional lymph node control in HPV positive @entity5 was not compromised by dose de-escalated radiotherapy to involved nodes in the setting of concurrent @entity900 based chemotherapy.
