In high risk prostate cancer treated with RT with neoadjuvant/concurrent ADT, is adjuvant intermittent ADT reasonable instead of continuous ADT?

As an option in general, I say no. Given multiple phase III trials showing an overall survival benefit of adjuvant ADT, I would need a robust non-inferiority study of intermittent ADT to recommend it.

If a patient refuses or cannot tolerate continuous ADT but can tolerate intermittent, this is probably better than nothing. But one would have to be very clear with the patient that this is not the strategy with best evidence.