Imaging with radiolabelled monoclonal antibody (MUJ591) to prostate-specific membrane antigen in staging of clinically localized prostatic carcinoma : comparison with clinical, surgical and histological staging

OBJECTIVE To evaluate the reliability of prostate scintigraphy using a radiolabelled antibody (MUJ591) raised against the external domain of prostate-specific membrane antigen (PSMA) in the staging of early prostate cancer. PATIENTS AND METHODS This was a prospective study of 16 patients who had radical retropubic prostatectomies (median PSA 9.75 ng/mL). All patients underwent PSMA imaging using MUJ591 radiolabelled with 99mTc using a photo-reduction technique. RESULTS The findings of prostate imaging and histology were identical in seven patients. Scans showed understaging and overstaging in six and three patients, respectively. CONCLUSIONS PSMA scintigraphy using 99mTc-labelled MUJ591 identifies the presence of prostate cancer, but is not sensitive in delineating micro-invasion of the capsule, seminal vesicles or bladder neck. As in other studies it seems to be useful in detecting prostate bed recurrence and distant micrometastasis.