Maybe for mundane fungal infections, idk, I’m an engineer so my medical background is pretty limited. @Erk is a doctor or something he might know.
But I don’t think it would work on a Mycus infection. The Mycus has actively adapted itself to survive in a variety of environments across multiple worlds and dimensions. While it doesn’t seem to like fire very much, that just means its flammable like any other vegetation, not that it cannot tolerate elevated ambient temperatures.
For example, IIRC the nature of plant and fungi cell structures makes them hardened against radiation compared to animal cells. So while you might be able to kill a Mycus infection with a radiation treatment, it would probably require an extremely high dose to do it.