Prostate cancer abdominal metastases detected with indium-111 capromab pendetide.

To provide appropriate therapy for prostate cancer, accurate staging of the patient's disease is essential. Determination of tumor size, location, periprostatic extension and metastatic disease in the skeleton and soft tissue are needed to stage properly. Current diagnostic modalities may lead to understaging in 40%-70% of prostate cancer. Detection of metastatic disease, both at the time of initial diagnosis and in patients with suspected local recurrence, can significantly alter the type of therapy given. Clinical studies using the (111)In radiolabeled immunoconjugate, MAb 7E11-C5.3-GYK-DTPA (capromab pendetide), have shown the superiority of radioimmunoscintigraphy over other diagnostic modalities in the detection of both primary and metastatic prostate cancer. Radioimmunoscintigraphy with capromab pendetide depends on expression of tumor-associated antigen rather than lesion size. Earlier detection of extraprostatic invasion and metastases by means of radioimmunoscintigraphy provides valuable information for treatment decisions. A case of metastatic prostate cancer in the abdomen of a patient without local disease, in which the extent of disease was confirmed at autopsy after sudden cardiac arrest, is presented.

Technical considerations for acquiring and processing indium-111 capromab pendetide images.

A diagnostic quality 111In capromab pendetide study depends on parameters such as the quality control of the camera, thorough patient preparation, adequate imaging time and accurate computer processing. Comparisons of different patient preparation methods, imaging times, and camera and processing parameters were evaluated to provide high-quality 111In capromab pendetide images and to develop acquisition and processing parameters for 111In capromab pendetide imaging. SPECT images provide the best views of metastatic pelvic nodal involvement. Volume rendered three-dimensional registration best differentiates between normal vasculature and metastatic disease. Optimal acquisition parameters for delayed imaging included 128 x 128 matrix and 65 sec/step. The LFOV dual-head SPECT camera required only one SPECT acquisition that encompassed both the pelvis and abdomen. Planar and SPECT positioning was critical in evaluating questionable lymph nodes. In processing these images, the most diagnostic results were obtained with a three-dimensional low-pass post filter. The most effective patient preparation consisted of an oral cathartic, enema and catheterization when needed.