Dr. Calais on the Role of PSMA-PET Imaging in mCRPC

Jeremie Calais, MD, MSc, associate professor of nuclear medicine and theranostics, David Geffen School of Medicine, University of California, Los Angeles (UCLA), UCLA Health, discusses the role of prostate-specific membrane antigen (PSMA)-PET imaging in metastatic-castrate resistant prostate cancer (mCRPC), and touches on the importance of integrating PSMA-PET imaging into community settings for clinical practice.

The development of PSMA-PET scans has allowed for earlier and more accurate detection of distant metastases in the lymph nodes, leading to a wider selection of treatment approaches, including radioligand therapy or chemotherapy, Calais begins. 

PSMA-PET scans have a special resolution that improves its detection capabilities, giving the scans an advantage over previous imaging techniques, Calais continues. Although the improved sensitivity of PSMA-PET imaging is beneficial, the expectations for the predictive value of this technique can be high, Calais qualifies. Clinicians may be tempted to de-escalate therapy in patients who produce a negative PSMA-PET scan, but this is not always the correct approach, he says.

Because the sensitivity of PSMA-PET imaging is around 40%, some patients with microscopic metastatic disease may still remain unidentified, Calais says. Furthermore, there is a whole-stage migration effect with more sensitive imaging techniques, he adds. This could potentially change the definition of mCRPC and requires a re-evaluation of how to apply prior data in this space, Calais states. 

As a novel, emerging technology, PSMA-PET imaging has been primarily performed in academic centers, Calais notes. Although it has begun to be utilized more widely in community settings, there is a large learning curve associated with this approach, Calais explains. Therefore, it is important for prescribing physicians, radiologists, medical oncologists, and nuclear medical physicians to work collaboratively to determine the best application of PSMA-PET scans, he states. This multidisciplinary approach is especially important because PSMA-PET scans can be employed at multiple disease stages, Calais concludes. 

Editor's note: Dr. Calais reports serving as a consultant or in an advisory role for Blue Earth Diagnostics, Curium Pharma, GE Healthcare, Janssen, Progenics, Telix Pharmaceuticals; he receieved honoraria from advanced accelerator applications, Progenics, Radiomedix