Current Status of PSMA PET in the United States
Philip J. Koo, MD, Division Chief of Diagnostic Imaging and Northwest Region Oncology Physician Executive at the Banner MD Anderson Cancer Center in Phoenix, Arizona, discusses PSMA PET and how it is poised to supplant conventional imaging techniques in the diagnosis of prostate cancer. He begins by observing the shortcomings of conventional imaging techniques such as bone scintigraphy and computed tomography. While these remain the current standard of care, they result in false negative diagnoses in most patients with biochemical recurrence, especially when the lesion is less than 1 cm with a PSA of <20 ng/ML. Dr. Koo then focuses on prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging. He cites a study that found PMSA has double the detection rates over fluciclovine, with an exception of lesions in the prostate bed, indicating that different tools may be appropriate depending on lesion location. However, Dr. Koo clarifies that there currently is no data that proves the superiority of a specific PET radiopharmaceutical. Additionally, he cautions that overdiagnosis using next-generation imaging, such as PSMA PET, is likely as physicians continue to learn the benefits and drawbacks. To that end, he notes that there is a spectrum of visible lesions when using PET and a threshold below which it cannot detect disease. Dr. Koo concludes that while conventional imaging is more readily available than next-generation imaging, its limited sensitivity indicates a necessary shift to more advanced tools like PMSA PET. Similarly, since prostate cancer will advance after initial treatment in 30-50% of patients, he sees an opportunity to use PSMA PET to identify patients who require further treatment or who have metastases undetected by conventional imaging.
Read More