Gallium PSMA PET/CT May Influence Management Plan in High Proportion of Patients
PSMA (prostate-specific membrane antigen) is found in prostate cancer cells and has elevated expression compared to benign prostatic tissue. Gallium scans using PSMA as a tracer (ie, 68GaPSMA-positron emission tomography [PET]/computed tomography [CT] scans) are reported to be more sensitive than conventional imaging techniques in patients with prostate cancer. Recently, a prospective multicenter study in Australia investigated how 68Ga-PSMA PET/CT scans impact patient management decisions in a population of patients with primary or recurrent prostate cancer. A total of 431 men were assessed with and without the use of 68Ga-PSMA PET/CT imaging to develop their management plans. The study included a mix of disease states, mostly patients being assessed for restaging/biochemical recurrence (75%) but also for primary staging of intermediate- and high-risk disease (25%). Overall, 68GaPSMA-PET/CT scanning led to a change in planned management in 51% of patients. For patients with biochemical failure after definitive surgery and/or radiation treatment, 62% had a change in management intent, compared with patients undergoing primary staging, where there was a 21% change in management intent. Imaging with 68GaPSMA-PET/CT revealed unsuspected disease in the prostate bed in 27% of patients, locoregional lymph nodes in 39%, and distant metastatic disease in 16% of patients.
Chief Medical Science Officer, Sema4
One of the issues right now is whether or not we can get better imaging so that, for patients with rising prostate-specific antigens (PSAs) and no overt metastasis, for instance, we can potentially use imaging to stratify these patients to get the appropriate specific therapy.
Currently, there is quite a bit of momentum in examining the failures of conventional imaging modalities (ie, bone scan and CT). It’s very frustrating for patients and clinicians to confront rising PSAs and no overt metastasis – these are patients for whom we may know that they have failed surgery and radiation and, nonetheless, we still can’t accurately locate the site of their malignancy. We’re seeing a lot of momentum with gallium and F-18 PSMA tests.
“We’re seeing a lot of momentum with gallium and F-18 PSMA tests.”