Top Line: Which advanced imaging technique is better for guiding focal treatment options in biochemically-recurrent prostate cancer: PSMA or choline PET?
The Study: That’s the question behind this Italian retrospective review of 88 patients with 118 oligomets from biochemically-recurrent castrate-sensitive prostate cancer. All patients received upfront SBRT (defined as ≥5 Gy per fraction) without further planned therapy to 1-3 isolated sites of disease on PET-choline (50%) or PET-PSMA (50%). First of all, at a median follow-up of 25 months, local control was reported as 100%. However, considering they boldly didn’t receive any systemic therapy at the time of biochemical recurrence, distant recurrences occurred in over half. An interesting primary endpoint was ADT-free survival after SBRT, a surrogate for quality of life presuming most men prefer to be without clinical evidence of disease while avoiding castration-level testosterone. As such, SBRT was recommended upon oligoprogression (≦3 new lesions) and ADT upon polyprogression (>3 new lesions). At one and two years, ADT-free survival was significantly higher in the PSMA cohort (88% and 82%) versus in the choline cohort (73% and 64%). However, pre-SBRT PSA was considerably lower in the PSMA cohort (0.58) versus choline (2.04). Indeed, there was no difference in ADT-free survival when looking only at patients with a pre-SBRT PSA >0.5.TBL: Excellent ADT-free survival can be achieved with early (and subsequent) SBRT to all sites of radiographic oligometastatic disease per advanced imaging for biochemically-recurrent castrate-sensitive prostate cancer. | Mazzola, Clin Genitourin Cancer 2020