Prostate massage after radiation

Hi all. I've searched the forums for a bit but wasn't able to find much in the way of this topic. To keep things brief: I'm wondering if prostate massage/stimulation is possible after radiation treatments. For a longer explanation: My partner had radiation treatment (I forget exactly which kind, it was one of the external beam radiation procedures but there's a whole list of different types of that and the name of his specific one escapes me right now) to treat (successfully) prostate cancer 4 years ago. He had never done any sort of prostate massage before we got together and we had only been together for about 2 years prior to the treatments. Since the treatments, we tried prostate massage/penetration a handful of times. Most of the time he says it doesn't hurt, but he's just not getting much of a feeling. He has indicated if has felt good at times but he doesn't feel like that feeling is coming from the prostate itself and even then the feeling wasn't remarkable. One of our last attempts he had his usual reaction (feels okay but I don't get what should be so amazing about this) but afterwards he said something that was encouraging. He indicated he felt "like he had just shot" so I asked what he meant specifically by that, he wasn't sure how to put it but said something similar to: "I'm having the feeling that I would have after an orgasm, like a pleasure fullness/release feeling. I didn't feel like I actually climaxed or anything really amazing, sort of like I skipped all that and just got to the relieved feeling". I asked him to clarify a little more if he could, such as was this feeling coming from all over, or more centralized to the groin/prostate area. He indicated he felt good in general all over, much the same as he would after an orgasm , but did notice the relieved feeling near his prostate. He said it could be in his prostate but just wasn't familiar enough with where exactly that was inside as he's still getting used to the area being directly stimulated but to his best guess it was the prostate.

I know prostate massage can be hard to get used to and for some men it just doesn't work at all. Everybody's different. But at the same time, I don't want to continue doing prostate massage if he feels like I'm forcing it on him or turning it into a chore. I'm usually the one to suggest it and he picks the time. I know his radiation has changed his anatomy, as he no longer really ejaculates in the traditional sense (it mostly is always retrograde ejaculation, with some of it slowly leaking out afterwards) but it seems like aside from ejaculate changes everything else seems mostly the same. He still is able to get erections and penetrate (with some difficulty for penetration, given him being 63 that's not a huge surprise or unexpected). So my question is pretty much this: does radiation of the prostate basically make prostate massage pointless/make it to where there just won't be much feeling associated with it? Or is it still a game of mindset, as in, if he feels closed minded or that he won't get good feeling from it, it won't happen and the reverse of that being if he's open minded and is willing to go with the flow he could start to make progress with prostate massage? I know it's impossible to say for sure, as everyone is different and radiation affects every prostate slightly differently from the next. I'm just wondering if there has ever been a general consensus/discussion about the topic.

Thanks for any feedback!