Radiocholine PET/CT has a niche in prostate imaging

Selection of patients with advanced prostate cancer who are eligible for salvage radiation therapy could be improved with the use of radiocholine PET/CT, according to a review of recent research published today in the Journal of Nuclear Medicine.

Luigi Mansi, MD, professor of diagnostic imaging and radiotherapy head of the nuclear medicine department director of the School of Specialty in Nuclear Medicine at the Second University of Naples in Italy, and colleagues examined how radiocholine PET/CT is finding the biochemical markers of recurrent prostate cancer.

Choline is an integral part of phospholipid synthesis and cell membrane integrity and it has an important role in cell proliferation, hence its possibilities in oncology imaging. F-11 choline is also in use. However, it does not have the lower urinary excretion of C-11 choline imaging.

“Because of the high probability of detecting positive findings outside the pelvis due to rapidly increasing prostate-specific antigen (PSA) levels, both as absolute and as kinetic values, despite ongoing androgen deprivation therapy, C-11 choline may select patients who really benefit from salvage radiation therapy,” wrote Mansi et al.

Yet there are limitations in the form of false positives due to benign prostate lesions and negatives due to primary lesions smaller than 5 millimeters. Some tweaking in the technique may be required. This application may be an ideal match for PET/MR. “MR imaging may also allow an increasing accuracy in diagnosing [patients with prostate cancer], mainly when functional techniques (functional MR imaging) or spectroscopy (MR spectroscopy) are feasible.”

The researchers noted that newer radiotracers including radioimmunotherapies conjugated with prostate specific membrane antigen (PSMA) have particular promise. Just a few of the other radiopharmaceuticals inching up the ladder in prostate cancer research include F-18 FACBC [1-amino-3-fluorocyclobutane-1-carboxylic acid], F-18 flucicovin, Ga-68 bombesin analogs, I-124 A11 PSCA and the experimental I-124 PUH71.