Immunoscintigraphy with indium-111-capromab pendetide: Evaluation before definitive therapy in patients with prostate cancer

Objectives. No standard noninvasive diagnostic test reliably differentiates patients with organ-confined prostate cancer from those with lymph node me tastases. The ability of a radiolabeled monoclonal antibody, indium-111 ((1 11)ln)-capromab pendetide, to identify sites of metastatic disease in patie nts at moderate to high risk of nodal involvement was investigated. Methods. The study prospectively evaluated 160 patients with prostate cance r scheduled to undergo pelvic lymph node dissection (PLND) before or during definitive treatment. All were at relatively high risk of nodal involvemen t by virtue of significantly elevated baseline prostate-specific antigen (P SA) values, Gleason scores, and/or locally advanced clinical stages of dise ase. The histologic findings of the PLNDs were compared with the results of immunoscintigraphy, computed tomography, and magnetic resonance imaging. Results. Among the 152 evaluable patients studied with (111)ln-capromab pen detide before PLND, the sensitivity of immunoscintigraphy for lymph node de tection was 62% and the specificity was 72%; the positive predictive value was 62% and the negative predictive value was 72%. In comparison, the sensi tivity of computed tomography and magnetic resonance imaging was 4% and 15% , respectively, and the specificity was 100% for both procedures on the bas is of a large number of negative interpretations. Logistic regression analy sis revealed that immunoscintigraphy with (111)ln-capromab pendetide provid ed strong, independent evidence of the presence of lymph node metastases. F urthermore, the analysis indicated that certain combinations of PSA, Gleaso n score, and (111)ln-capromab pendetide were particularly effective at pred icting the risk of nodal involvement. Conclusions. Immunoscintigraphy with (111)ln-capromab pendetide outperforme d standard diagnostic imaging techniques in the detection of prostate cance r lymph node metastases and provided independent prognostic information tha t complemented PSA, Gleason score, and clinical stage. (C) 1999, Elsevier S cience Inc.