Prostate surgery, RASP

Hubby is scheduled for robot assisted simple prostatectomy next month. Very large prostate, 160cc. Surgery is similar to TURP, except there will be incisions. Later after healing, he will have radiation. Meeting with the RO on the 18th to discuss what radiation treatments will be suggested. My questions are, is there anyone age 72(turning 73 month after surgery), that had surgery, then radiation at his age? Are side effects worse for an elderly man? Want to ask the RO, if radiation can be taken off the table, as the prostate will be basically cored, with just the capsule left. Wouldn’t all of the cancer be removed with the RASP? Couldn’t we just have PSA checks every couple of months? Would like hubby not to have radiation if possible. Doctor said there will be almost no incontinence or ED. Won’t radiation cause ED and incontinence? I’ve read the stories, but most of them were problems coupled with radical prostatectomy and radiation.
Appreciate any feedback. Thank you.