For RT, both as primary tx and salvage tx, there is a clear patient and provider interest in fewer number of total txs.
However, the total radiation dose appears to be the same; less sessions; higher dose per session.
I received Salvage Radiation 37 txs of IMRT for a total dose of 66.6 gy to the entire prostate bed (45 gy to the lymph nodes); 1.8 gy per session. Daily for almost 8 wks.
Of course a shorter treatment course (measured in time/number of txs) would have been appealing.
My concern would be the higher radiation doses per tx, if the goal remains a total of 70 gy in your case, or 66.6 in my case.
I could pontificate/speculate additionally (without sound basis) about patient, provider and insurer interests, but maybe retired Radiologist has a more educated and nuanced thought on this.
Anyway, I cannot discern any residual side effects from my salvage radiation treatments, now 12 months ago. And unless there is a PCa tx therapeutic benefit, the lower daily dose of radiation over a longer period of time sounds "safer" (as if I have any idea of what is "safer" regarding radiation).
Enough from me.
We, and I believe our providers, are all hoping for the safest and most effective treatments.
Best to all.