Multimodal Imaging for Prostate Cancer

SPECT scanning of 111In-labeled ProstaScint has demonstrated its abilities to identify prostate cancer, both primary and metastatic. In this study, we evaluated the merits of multimodal imaging in localizing intra-prostate cancer with in vitro imaging and histological findings as the “gold standards”. Pelvic images of delayed SPECT scanning of 111In-labeled ProstaScint were acquired on pre-surgery patients with prostate cancer. MRI or CT images of the same patients were also obtained and registered with SPECT images to provide anatomical references. The gland was fixed in buffered formalin and cut into 4 mm transverse slices for in vitro autoradiography. The histological sections were warped to align with the anatomical structures on the matching MRI or CT slices. With image registration (including warping), comparison among the multimodal images for prostate cancer were performed. Large lesions on autoradiograph, in general, correlated well with the histological mapping. In contrast, in vivo SPECT images of ProstaScint were inconsistent. It was difficult to detect small lesions with 111In-ProstaScint in vitro. Conducting the SPECT scan properly appears to be an important issue.

Gleason 6 throughout right lobe of prostate extending into seminal vesicle