Utility of capromab pendetide (ProstaScint) imaging in the management of prostate cancer

Abstract

Purpose: Capromab pendetide (ProstaScint) is an indium In 111 ((111)In)-labeled monoclonal antibody to prostate-specific membrane antigen (PSMA) used to image prostate cancer. The appropriate techniques for obtaining images with this modality and the appropriate clinical indications for this study are in the process of being optimized.

Materials and methods: From 1994 to 2000, 631 monoclonal antibody imaging studies with (111)In capromab pendetide were performed. The accuracy and utility of this modality in the primary staging of patients with disease at high risk of metastasis and patients with recurrent or residual disease after primary therapy were evaluated.

Results: In high-risk patients evaluated for risk of lymph node metastases prior to pelvic lymph node dissection, capromab pendetide imaging was found to have a positive predictive value (PPV) of 62%, negative predictive value (NPV) of 72%, sensitivity of 62%, and specificity of 72%. In patients evaluated with capromab pendetide imaging for prostatic fossa recurrence using prostatic fossa needle biopsy as the gold standard, capromab pendetide imaging was found to have a PPV of 50%, NPV of 70%, sensitivity of 49%, and specificity of 71%.

Conclusions: The sensitivity and NPV of (111)In capromab pendetide imaging are better than those of computed tomography and magnetic resonance imaging for detection of soft-tissue and nodal metastases from prostate cancer. The utility of this modality has been demonstrated in the primary staging of patients with disease at high risk of metastasis. Patients with recurrent or residual disease after primary therapy also may benefit from capromab pendetide imaging prior to selection of salvage therapy. Innovative methods for the use of capromab pendetide imaging in radiation therapy treatment planning are under development.