How would you approach cT3N0M0 squamous cell carcinoma of the supraglottic larynx in a patient with a history of breast cancer and prior radiation to the supraclavicular fossa?

I would try and get the prior radiation treatment plan to ensure that the supraclavicular fossa was adequately treated and to determine exactly how high up the fields went and attempt to match elective nodal coverage to about that level. In the absence of the prior radiation information, I would likely treat level 4a on that side (as I would in any other T3 supraglottic larynx case) and likely "cheat" a bit on the inferior border.

Unless there was a long time gap between breast RT and new larynx cancer, I do not feel the need to re-irradiate any previously treated nodal drainage (assuming that that area got a dose of ~50 Gy in 25 fx).