Would you consider neoadjuvant immunotherapy followed by radiation for a patient with locally advanced basal cell carcinoma?

This is a relatively data-free area, so there's no “right” answer.

I think the first question to ask is whether this basal cell carcinoma (BCC) is amenable to curative intent radiotherapy (assuming surgery is not possible). If so, any adjunctive drug therapies are of secondary relevance.

For locally a...

It depends on both goals and, if curative, on whether you believe a response to I/O will allow you to tailor your high-dose target volumes potentially off critical structures.

The latter is because most reasons for "unresectability" are proximity to or involvement of ocular or cerebral structures.

If ...

Having treated a lot of skin cancer over the last 35+ years, my personal experience is that radiation alone will cure large (5-10+ cm) BCCs >80% of the time.