In 3 years it's gone from 0.02 to 0.16.
0.02 > 0.04 > 0.08 > 0.16 is the doubling rate. So it's doubling approx every year although it might not have risen like that and perhaps the gap of the last result is more significant. That's fairly slow which is usually not bad. I find it hard to say good as it's never good, although it's in the better zone.
Has he been referred to Oncology from Urology.
As said above he's getting close to the point where a scan will be more meaningful although it's always a trade off between letting the psa rise to make the scan more accurate and having treatment as soon as possible.
I think with your husband's rise it's likely to be less of a gamble to say the recurrance is in the prostate bed and they could aim the RT at that without a scan. That was and still is a common way of doing it although modern PSMA scans are now changing it so that people have a psma scan first. Scans are normally better at finding one larger lesion at lower psa levels than a few smaller ones.
I'm not at all qualified to say. Some people have found a scan redirected their treatment so it's a choice for you and the skill of the oncologist. I think I'm going to be in this situation and think I'll ask for a scan at a low level or pay for one but want to hear what the Oncologist says. I'm still with Urology as it hasn't got that high yet. Hope it's good for you. Regards Peter