The comment "too many cores for brachytherapy" sounds suspicious to me. I've heard of a prostate being too large for seeds to be effective, but either the seed method, or the high dose rate (HDR) method with temporarily placed needles can be effective for many men.
What is his PSA now? Unless it's quite high, I bet the bone scan comes back clear.
External beam radiation therapy requires a lot of cooperation on the patient's part, so depending on his mental and physical state that may or may not work very well. Have you talked to a good radiologic oncologist yet? Your uro is a surgeon, and if he told you radiation therapy won't work you need to recognize that's coming from a certain viewpoint. Radiation therapy has advanced considerably in just the last few years.
Depending on the progression of his Parkinson's, it may even be worth thinking hard about
whether it's necessary to treat this prostate cancer at all. A G7 4+3 is serious, and generally will require treatment of some type, but that really depends on the patient's whole picture.
Hang in there, it sounds like you're a great support for him, and that he is likely to be relying on you a great deal. Take some time for yourself too, so you can stay strong. The caregivers really go through a lot, and carry some large burdens! Have you found the caregiver's thread here yet? There are a number of them that share there for mutual support. Here's a link to it:www.healingwell.com/community/default.aspx?f=35&m=3009873
All the best to you both, and on this Thanksgiving day let's remember to be thankful for the blessings we do have!
IGRT by IMRT, 44 done 8/28/13: 50.4 Gy pelvic nodes, 79.2 Gy prostate
ADT2 3 yrs: Lupron/Casodex 5/1/13
Age 57: 55@Dx 4/16/13-
Bx 6/12 pos G9=5+4 (80%, 60%), 4+5 (2 at 100%, 80%, 10%), PNI+
3T MRI: Bilateral EPE, NVB+, SV-, LN-, cT3a
Date PSA fPSA
2/6/14 <0.01, T<10
8/13 <0.1 (ADT2, post-RT)
3/13 5.2 12% PCA3=31
9/12 4.1 15%