Radiotherapy and exercise

HiCattyB​ I was similar toSelkie​ and think the months of adjuvant chemo (plus getting Covid!) probably meant I was fairly depleted by the time I got to radiotherapy. I did a modified oncology exercise rehab program and had just one instance of very low blood pressure and had to be helped - I was glad to be in an environment with back up. 
I used to row on a rower but after dose 3 I just didn’t have the confidence and energy. The surgeon wasn’t keen on too much upper body strength work in the weeks after my lumpectomy, so I paused until all my treatments were behind me. 
I came to yoga later, it’s been terrific for me. I was cautious but started with some modified yoga and then regular yoga.
I am inclined to consult your oncologist and radiation oncologist and keep an open mind, asSelkie​  said to be prepared to rest  if it turns out that you’re feeling out of steam. Sending all good wishes as you crack on with your treatment-