“This is a great study. It is one of the largest series of prostate-specific membrane antigen (PSMA) scans and covers many patient scenarios, including initial staging, restaging after surgery or radiation or hormonal therapy, and re-imaging in advanced disease,” said Charles G. Drake, MD, PhD, a proponent of PSMA positron-emission tomography (PET)/computed tomography (CT) scanning. Dr. Drake leads the GU Oncology Program at the Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, where he also co-directs the Cancer Immunotherapy Program.
Charles G. Drake, MD, PhD
“The implications for the scan vary in each setting. If a patient has a diagnosis of local disease but has PSMA-avid lymph nodes, one might consider radiotherapy as initial treatment and include those nodes in the treatment plan. A harder question is what to do when a patient thought to have localized disease turns out to have a distant lesion and whether to consider treating that as metastatic disease. We need randomized trials of PSMA PET/CT to determine the best way to approach scenarios like that. The changes in treatment plan shown by this study tell us how it is likely to be used—but not how PSMA scans should be used,” he said.
“We really don’t know the long-term implications of detecting PSMA-avid lesions. This poster says that physicians note the lesions … and that at least half the time they change treatment based on these findings. PSMA PET/CT is most useful for a rising PSA after primary treatment. In some centers in Europe, PSMA PET/CT is done first, before CT or bone scan. PSMA PET/CT is more than 90% specific, much higher than conventional technicium bone scans. I do believe that these scans represent the future of prostate cancer imaging,” Dr. Drake stated. “Once PSMA PET/CT is approved, it will be widely used, most commonly for patients with a rapidly rising PSA doubling time after surgery or radiation. We look forward to that occurring.”
DISCLOSURE: Dr. Drake holds stock or other ownership interests in Compugen, Harpoon Therapeutics, Kleo Pharmaceuticals, Tizona Therapeutics Inc, Urogen Pharma, and Werewolf; has served in a consulting or advisory role for AstraZeneca/MedImmune, Bayer, Bristol-Myers Squibb, Compugen, F-Star, Ferring, Genocea Biosciences, Janssen Oncology, Kleo Pharmaceuticals, Merck, Merck/Serono, Pfizer, Pierre Fabre, Roche/Genentech, Shattuck Labs, Tizona Therapeutics, Urogen Pharma, and Werewolf; has received institutional research funding from Bristol-Myers Squibb; holds institutional patents licensed to Bristol-Myers Squibb and Potenza Therapeutics; and has been reimbursed for travel, accommodations, or other expenses by the American Association for Cancer Research, ASCO, and BMS.
