ASCO 2017: Effect of Ga-68 PSMA-11 PET on management in patients with recurrent prostate cancer
Overall, 150 patients from December 2015 to October 2016 were enrolled in this prospective trial evaluating the use of PSMA PET in the staging of PC patients. Inclusion criteria required a PSA doubling time less than 12 months. 63 patients were imaged using PET/CT (GE Discovery VCT) and 63 patients using PET/MRI (GE Signa 3.0T PET/MRI). Referring clinicians filled out a pretreatment management form and a management form based on the imaging results. Changes in management were graded as major, minor, no change, or unknown based upon the responses.
A total of 126 forms were received with an 84% response rate. The average PSA in the population was 5.9 ± 5.4 ng/mL with an average doubling time of 9.7 ± 11.0 months, and 49 patients had a PSA of less than 2.0 at the time of imaging. The average time between prior treatment and imaging (RP and/or radiation) was 5.3 ± 5.4 years, with 46 patients imaged within two years of their most recent treatment. 43 patients had a prior prostatectomy, 41 prior to radiation, and 33 patients had both. 103 patients (82%) had disease localized on PSMA imaging. Of the 126 patients, 67 (53%) of the imaging studies resulted in a major change in management. The most common major change was converting from active surveillance to radiation therapy (15 patients, 12%), changing from androgen deprivation therapy (ADT) to radiation therapy (16 patients, 13%), and converting from radiation therapy to either active surveillance (6 patients, 5%) or to ADT alone (3 patients, 2%). 10 patients (8%) had a minor change, 42 patients (33%) had no change, and 7 patients (6%) had an unknown change in management.
The results of our surveys demonstrate a substantial impact of PSMA PET on the intended patient management. The majority of changes involved converting a targeted therapy to systemic treatment, or systemic treatment to a targeted therapy. Prospective studies are warranted to determine whether directed treatment towards PSMA-avid lesions affects long-term disease outcomes.
Presented by: Tom Hope, MD, University of California San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, CA
Written By: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
Twitter: @GoldbergHanan
at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 - Chicago, Illinois, USA