Some consultants seem to have fairly fixed PSA levels for resuming HT whilst others consider the history/rate of rise and response/ of the individual to treatment(s) and his type of cancer and if it is thought it can be further treated specifically rather than systemically. So the starting point for resumption may vary, even in the case of an individual. After RT I was told variously if my PSA reached 4 and 10, (depending on consultant), further treatment involving HT would be advised. I then had HIFU at 1.99 and it was suggested I also started HT at that time but I decided against it which was also the recommendation of a different hospital. More than 18 months on and following more PSA's and scans, my consultant said I had done well NOT to start the HT. However, if my PSA doubles from the latest figure of 0.66 I should resume HT I am told, so yet another figure!