All and nothing.
The Study: Now we’re bringing you the full pub. Remember, this phase 2 trial enrolled 72 patients post-resection of mucosal H&N squamous cell carcinoma (SCC) with bilateral (n=66) or ipsilateral (n=6) neck dissections with at least one pN0 hemi-neck. All merited post-op radiation for the standard reasons (e.g., close or positive margins, perineural invasion, extranodal nodal extension, etc), and all received standard conventionally-fractionated post-op doses. Some (n=34) also got concurrent chemo when indicted. The kicker is that no one received radiation to any hemi-neck that was pN0, with a hypothesis that local control in the unirradiated hemi-neck would remain >90%. With 11 bilateral pN0 necks and another 6 pN0 necks after ipsilateral dissection only, a quarter of patients (n=17) received post-op radiation to the primary tumor bed alone and the other three-quarters (n=55) to the primary tumor bed and dissected pN+ hemi-neck alone. Again, at a median follow-up of 4.5 years, the primary endpoint of failure in an untreated pN0 hemi-neck occurred in two patients (3%), and both had synchronous failures in their treated primaries.
TBL: Omission of post-op radiation to a pN0 hemi-neck in the setting of otherwise standard post-op H&N radiation results in zero isolated recurrences in the untreated neck. | Contreras, J Clin Oncol 2019