One of our members, suz and Steve, was just treated with SBRT by Kevin Stephans at Cleveland Clinic and spoke very highly of him. You can put the name in the search bar to read her comments.
As a primary therapy, IMRT, in my opinion, is a relic of the past. (Although we have yet to see the results of a randomized comparative trial.) Many ROs are holding onto IMRT for dear life because they charge per treatment - 40 treatments vs 5. Their income is cut in half by switching to SBRT.
There is no basis for that doctor's assertion that side effects are any worse. In fact, the data lean in the opposite direction. Read this article:
Quality of life after three different first-line radiation therapies for localized disease: Part 2As you can see, SBRT outperforms IMRT on all quality of life measures - urinary, rectal and sexual.
For the latest (9 year) SBRT results, see the link in my signature.