The Study: We know the addition of a brachytherapy boost to external beam radiation (EBRT) prolongs time to biochemical failure. Now let’s take a big retrospective look at >1800 patients with GS 9-10 prostate cancer treated at 12 centers (11 in the US and 1 in Norway...because who doesn’t <3 Norwegians). Outcomes were compared after three treatment paradigms: radical prostatectomy (RP)  or androgen deprivation therapy (ADT) + EBRT without  or with  a brachy boost. Note: the median EQD2s without and with brachy were 74 and 92 Gy. There was a pretty even divide between treatment groups, but the rates of distant mets (DM) and even prostate cancer-specific mortality (PCSM) were nowhere near evenly divided. The respective adjusted rates at 5 years of DM were 24%, 24% and 8% and of PCSM were 12%, 13%, and 3%. And this is all despite a stark difference in median time of ADT when given without (22 months) and with (12 months) a brachy boost.
Bottom Line: Extremely high risk (GS 9-10) prostate cancer may call for extremely dose-escalated radiation to decrease mets and cancer mortality, all in conjunction with ADT...for now.