Is post-operative radiotherapy indicated in HPV associated, < 10 pack year smoking, low volume (i.e. T1N1) squamous cell carcinomas of the head and neck when the only adverse risk feature present on pathology is LVSI?   

LVSI has been shown to increase the risk of regionally recurrent and metastatic disease as an independent risk factor (and even worse in terms of DFI and DFS in patients with concurrent PNI). The question I'd ask is what is the appropriate volume of disease to treat. These days we are minimizing our...