Posted: Wednesday, February 8, 2023
Although PET and MRI are useful in delineating anatomic features of tumors prior to radiotherapy, these conventional imaging techniques provide little information about the biologic characteristics of the tumors. Prostate-specific membrane antigen (PSMA), a transmembrane glycoprotein overexpressed in most prostate cancer cells, is an important biomarker for identifying primary tumor and metastatic prostate cancer cells. In a study published in Cancer Imaging, Xiang et al, of Tongji University, Shanghai, China, investigated the value of combining PSMA data with PET/MRI in assessing radiotherapy clinical target volumes in patients with prostate cancer.
A total of 49 patients with high-risk prostate cancer who received MRI or PET/MRI with PSMA detection were retrospectively evaluated between May 2020 and December 2021. None of the patients had received treatment prior to enrollment. The size and overlap of clinical target volume and nodal gross tumor volume were measured.
The study found little difference in the clinical target volume delineated when either MRI or PET/MRI were employed. However, when nodal gross tumor volume was measured, the addition of PET to MRI identified metastatic pelvic lymph nodes more accurately, and in eight patients, the addition of PSMA data was helpful in redefining the N and M stages. Although not found to be statistically significant, the researchers believe the addition of PSMA data contributed to more individualized radiotherapy. The practical application value of such data with PET/MRI requires further investigation in large, well-designed, randomized, controlled trials.
Disclosure: The study authors reported no conflicts of interest.