Increasing PSA could be due to some regeneration of cells in the Prostate which is quite usual with a previously radiated Prostate or could be a new tumour. If the latter, the chances are small at present of it being found in a scan with a PSA so low. I would not be surprised if consultant wants another PSA test to check whether the last one was a spike for some reason or showing an accelerated upward trend, perhaps in 3 months or sooner. However, we know that consultants can differ in the way they react to PSA results, some seemingly being more proactive in instigating more tests/treatment than others. You have done what you can and I don't think can do more for the time being pending. I think it will be more for an oncologist to take forward if PSA continues move upwards more steeply.