Can you skip elective inguinal treatment in PET negative squamous cell carcinoma of anal canal?  

This is an interesting question. There are a few small series that suggest that the negative predictive value of a PET-CT may be quite high (100% in the study by Mistrangelo, IJROBP, 2012). However, the gold standard in these results was sentinel lymph node biopsy, not inguinal lymph node dissection...

If regional node prophylactic treatment is given , I would favor 45 Gy / 5 weeks,since this time/dose regimen has been clinically and statistically well established as very effective for control of sub local disease in lymph nodes by Fletcher et al —and ,any other dose /time relationships are ...