ADT & Osteoporosis

I am 66 and my biopsy came back + with a gleason 8. There was blood in my urine sample so urologist sent me for a cystoscopy to check my bladder for lesions. The cystoscopy showed a tumor growing out of the duct from my prostate into the urethra. I then had a TURP to cut out the tumor. That left me waiting 2 months to begin EBRT. My Oncologist prescribed 4 months of Bicalutamide (Casodex) and 18 months of Eligard. I had a Dexa scan to base line my bone density and surprise! I have osteoporosis in my spine and hips. I am now 18 days into 25 day beam radiation treatment and looking forward to brachytherapy next month.
I am very confidant of my Oncologist and my rheumatologist. However, I am concerned about the ADT accelerating the osteoporosis and leaving me cancer free but fragile. Next week I am starting Reclast infusion to help with the bone density.
I am considering a somewhat shortened course of Eligard - maybe 12 months instead of 18 months.
Sure appreciate all the stories here on the PC board.