External Radiation Question -- Metastatic

Having external radiation treatment for bone lesion. I don't know what this really does.

I have been treated for over two years with different treatments after diagnosis of metastatic prostate ca. The last treatment was with an isotope, Radium 223 (Xofigo), with mixed results. Now waiting for DNA sequence to see whether I qualify for a clinical trial.

The upcoming radiation treatment is supposed to be for pain only, I think. But does it also arrest the cancer on that spot. I can't seem to get a clear answer from the doctors. The last time I had this treatment I had significant side effects including fatigue and digestive issues.

Anyone know?

Thanks.

As Andrew said, it's for pain and to prevent fractures and other adverse bone events, but it usually gives at least temporary local control (hopefully, stopping further damage at that place)as well, depending on the dose.

When a scan showed I had a single met on vertebra T-10, (no pain) my MO said radiation was useless at this point. I checked in with my RO and we both came to the conclusion that killing that one detected met could not hurt anything and it could possibly slow down the cancer progression and prevent spinal damage..The find it and kill it approach.. SBRT was used, also called Cyberknife by some, 5 treatments, I was done in a week. No side-effects at all. My PSA dropped to undetectable (my MO put me on Zytiga at the same time). Next full body bone scan will be in October.

This approach would not work if multiple mets are involved, the radiation dose becoming too high....