How would you treat a melanoma of the penile skin in a medically inoperable patient?  

As above, IO is probably preferred. That being said, I’ve had surprising responses when I thought I was treating palliatively. Although as a group thought to be radiosensitive, it is heterogeneous. I once had a CR with 30/10 in a quite ugly mass (for some reason he got biopsied and no tumor ...

Systemic IO would be a preferred option for unresectable melanoma.