68Ga-PSMA PET and multiparametric MRI combo may help diagnose prostate cancer and predict its aggressiveness: Study

India: A recent study explored the histopathological correlation of robotic-assisted radical prostatectomy (RARP) specimens with simultaneous 68Ga-PSMA PET/MRI imaging in cases of prostate adenocarcinoma. 

The findings, published online in Apollo Medicine, suggest that the prediction and localization of histological malignancy in the prostate can be enhanced pre-operatively by incorporating 68Ga-PSMA PET with mpMRI imaging. Additionally, the standardized uptake value (SUV) of abnormal 68Ga-PSMA radiotracer uptake serves as a reliable indicator of tumor aggressiveness, as evidenced by its correlation with the Gleason score.

Dr. Rajesh Taneja, Department of Urology and Robotic Surgery, Indraprastha Apollo Hospitals, Sarita Vihar, New Delhi, Delhi, India, explains the study's major takeaway to Medical Dialogues: "Combining PSMA PET technology with simultaneous MRI by fusing the images significantly enhances the diagnostic accuracy for prostate cancer when compared to using individual mpMRI or PSMA PET scans. Furthermore, the study highlights that the grade of tumor aggressiveness is correlated with the maximum standardized uptake value (SUV max) of the PSMA PET scan in robotic-assisted radical prostatectomy specimens."

Dr. Taneja further adds, "This study clearly shows that if PSMA PET is fused simultaneously with mpMRI of the prostate, then the diagnosis of cancer can be made with more certainty as compared to either of the imaging modalities alone. It can also be used to predict the aggressiveness of malignancy."

68Ga-PSMA PET is emerging as a promising biomarker for detecting prostate cancer (CaP). When combined with simultaneous multiparametric MRI (mpMRI), 68Ga-PSMA PET enhances the detection and localization of primary prostate cancer. It is crucial to correlate histopathological findings from robotic-assisted radical prostatectomy specimens with pre-operative PSMA PET/MRI imaging to validate their diagnostic accuracy. Additionally, PSMA imaging has shown potential in assessing the aggressiveness of prostate cancer.

Against the above background, Dr. Taneja and his team set out to examine the correlation between histopathological findings from RARP specimens and pre-operative combined 68Ga-PSMA PET/MRI imaging to establish their diagnostic and prognostic value.

For this purpose, the research team synchronized specimens obtained after robotic-assisted radical prostatectomy (RARP) in 38 patients with localized prostate cancer (CaP) with pre-operative images acquired through simultaneous 68Ga-PSMA PET/MRI. The maximum scores of individual parameters, including PI-RADS, Gleason’s score, and PSMA uptake (measured in SUV) for each sector, were analyzed statistically to assess correlations and diagnostic accuracy. 

Dr. Rajesh Taneja highlights that the study is limited by the number of specimens analyzed and emphasizes the need for multicentric studies. This is important because the experience of radiologists and nuclear medicine technicians with PSMA PET scans may vary, given that the technology is still evolving.

Dr. Taneja further notes that this study is unique because the specimens removed after robotic-assisted radical prostatectomy were carefully matched slice-by-slice with imaging, requiring close coordination among pathologists, radiologists, and nuclear medicine experts. This approach could potentially pave the way for robotic surgery without the need for biopsy in the future and may also help predict long-term patient outcomes based on the SUV max values.

Reference:

Kumar, S., Jena, A., Taneja, S., Kashyap, V., Singh, A. K., Sharma, A., Taneja, N., Raheja, A., & Taneja, R. (2024). Histopathological Correlation of Robotic-Assisted Radical Prostatectomy Specimen with Simultaneous 68GA-PSMA PET/MRI Findings in Cases of Adenocarcinoma Prostate. Apollo Medicine. https://doi.org/10.1177/0976001624127771