AUA 2017: Robot-Assisted Salvage Node Dissection for Oligometastatic Nodal Disease Detected by 68-Gallium-PSMA PET/CT: A Multicentre Retrospective Series

Boston, MA (UroToday.com) With the recent advent of 68-Ga prostate specific membrane antigen (PSMA) PET/CT, robot-assisted salvage node dissection (RASND) is offering prostate cancer (PC) patients with subsequent biochemical recurrence (BCR) a potential for curative treatment. On behalf of the Garvan Institute of Medical Research, Mr. Anton Kalsbeek presents a retrospective cohort analysis of patients undergoing RASND for oligometastatic node-only disease recurrence post-primary treatment with indication by 68-Ga PSMA PET/CT.

Two institutions in Brisbane, Australia contributed a total of 35 patients from February 2014 to April 2016. Treatment was analyzed with primary endpoints of safety and oncological effectiveness based on PSA response to RASND defined per primary treatment: primary prostatectomy patients required a 6-week post-operative PSA less than 0.2 ng/mL or first PSA less than 0.03 ng/mL; those who underwent primary radiotherapy were included only if they had a 6-week PSA less than post-RT nadir.

Consistent with previous published reports from the center, median PSA at the time of 68-Ga PSMA PET/CT was 2.2 ng/mL at a median time from primary treatment of 61.3 months. Of the 35 patients undergoing RASND, 14 patients had targeted dissection to 68-Ga PSMA PET/CT identified lesions, 19 patients underwent extended template dissections, and 2 with a combination of both. Interestingly, while a total of only 58 lesions were detected with PSMA imaging, 87 lymph node metastases were excised (out of 372 lymph nodes removed in total) at a median of 2 metastases per patient confirmed with positive histopathology in 91% of the patients undergoing RASND.

At a median follow-up of 12 months, a treatment response via PSA was seen in 42.9% of patients with PSA < 0.2 ng/mL and 31.4% of patients had an undetectable PSA. Confirmed clinical progression occurred in 12 patients (34.3%), of which two had an initial treatment response.

Overall, RASND per indication by 68-Ga PSMA PET/CT presents with low complication rate and the potential for curative salvage treatment. However, over a third of the patients in this series did experience treatment failure and, thus, represent the need for maturation of data on RASND’s attendant impact on long-term BCR-free survival and prostate cancer specific mortality.

Presented By: Anton Kalsbeek, MSc, Garvan Institute of Medical Research

Authors: Amila Siriwardana, James Thompson, Shaela Doig, Pim van Leeuwen, Anton Kalsbeek, Louise Emmett, Warick Delprado, Hemamali Samaratunga, Anne-Maree Hayn

Written By: Linda Huynh (BS), an assistant research specialist from the University of California, Irvine, on behalf of UroToday.com

at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA