My understanding is that a prostate under 42 grams is preferred as it is
easier to cover the entire area with seeds, without missing sections.
However larger prostates can be reduced in size, using proscar or
Lupriton, to make seed inplants feasible.

I would not say that it is "not" used for large prostate, but it is less
effective the larger the prostate.  Several issues:

Not recommended for someone with a gland larger that 50 grams...  anything
over 50 or 60 grams, even in the most skilled hands, may be too large to
treat safely with seeds, increasing the risk of acute urinary retention
after the implant and adding to the risk tha thprostate will not be saturted
with enough seeds to affet a cure. -- Scardino

However, initial use of HT may shrink the gland ot the ideal weight of 40
grams.

Steve Kramer is right on re the max. gland size and sufficient
coverage.

Permanent Seeds can also migrate and cause all sorts of problems.

I had a 72cc Prostate and it didn't shrink much on ADT...around 65cc,
but I had HDR Temporary Brachytherapy where they wound up the dose and
the intensity "to boil the whole Prostate into one huge Blister" (as
quoted by one of the Technicians during my blasts.)
With Permanent Seeds, you cannot do this.

My outcome, however, is not so good, having had severe Urinary
problems like partial blockage and large retention rates for 8 mths
now. Self-Catherisation is an option for Emergencies, but I've ducked
it due to the No. of guys back in Hospital on IV drips clearing up
Infections from over use re-use, plus it makes the Bladder Sphincter
lazy and you have to retrain yourself to Urinate by doing Kegel
Exercises under supervision of a Continence Educator.

The bad part is, I have to wait a minimum of 12 mths for the tissue to
grow back for a TURP to ease the problem.

-- Reader to complete...
-- Please reply to this ng as my email adress is fake:

-- Regards

-- CC

According to the info I received from my  HMO before my brachytherapy, this
is the reason large prostates are not suited for implants.

"Large prostate glands(>50 cc) are often too wide and thick to implant as
the bones forming the pubic arch block accurate placement of the seeds in
the periphery of the gland."

"In this situation it is necessary to shrink the gland before PSI can be
performed",
Woody

Yes, in my experience. The reason seems to be that a very large
prostate requires more seeds to effectively irradiate the entire
prostate, thus increasing inflammation and swelling in the surrounding
tissues-- leading to, among other things, more bladder and urethra
inflammation, urine retention and radiation proctitis.  I know, because
I have had these problems for 9 months.  Good idea to shrink the
prostate first.