Considering the surgical margins used in TORS, is it necessary to cover the entire tongue base with an elective dose in IMRT of cT1-3 HPV+ squamous cell carcinoma grossly involving one side of the base of tongue?   

Frankly, I see no point in doing TORS if a patient is likely to require postop RT unless you believe that you can safely treat neck only (which includes unavoidably part of the ipsilateral oropharynx to irradiate the RP nodes). And I do not (but have been wrong before). Particularly HPV positive no...

While it is a question of how rigorously the details of ECOG 3311 protocol were followed, and there remains further debate whether primary site coverage is necessary if the only risk is the neck, the protocol specifically discouraged large volumes: "5.1.11.2 Guidelines for Target Volume Delineation...

I was asked to update the responses, and after review, I'm not sure much has changed since the excellent responses above, beginning in 2020. In general, the field is progressively more comfortable with tighter margins around gross tumor when delivering definitive chemoRT. The margins are tighter in...

I usually do, and treat both sides of the neck.

I do not electively include the entire tongue base in Post-TORS RT planning. I use contrast enhanced simulation CT with a narrow field of view (for better tissue delineation) to outline the surgical bed. Having said that, it is not always easy to delineate surgical bed with 100% conviction. In those...

Almost certainly not as long as margins are 2 mm+ - the AVOID-RT study showed excellent local control when omitting the primary site completely (though when covering the RP space primary site still gets some dose) when margins >2 mm - Swisher-McClure et al., PMID 31785337. Our institutional data ...

Thank you for your responses so far. I would like to disclose that I asked the question. Practice certainly varies on expansions (i.e., GTVp->CTVp->PTV, just GTVp->PTV, intermediate dose expansion [sometimes called PTVp2], no intermediate dose, etc). If I may clarify my question: During d...