I had my chemo first, six visits to hospital with a drip in my arm for an hour at a time, three weeks between sessions. The first one was early August and the last in late November, so that meant 18 weeks of self-isolation while my immune system was compromised. At least that ended in time to spend Christmas with the grandchildren.
The hair loss didn't start too show until November, but then I didn't have much to start with apart from my beard. What's left of the beard is looking threadbare at present. I'm still waiting for my hair to start growing again, I'm told that could take three or four months.
The radiotherapy is intended to to kill off as much as possible of the prostate tumour, removing/reducing the source to cut the risk of it spreading any further.