Helical CT of prostate cancer: early clinical experience

[corrected] This study was undertaken to determine whether helical CT can reveal carcinoma of the prostate detected at transrectal sonographically guided biopsy.

Helical CT of the prostate was performed in 35 patients: 25 with proven prostate cancer (group I) and 10 without cancer detected at biopsy (group II). All patients in group I had cancer in the peripheral zone, and three of these showed foci of cancer in the transitional zone. All patients of group II had undergone at least two sets of biopsy before CT. In group I, areas of contrast enhancement in the peripheral zone of the prostate were defined as suggestive of cancer and correlated with the histopathologic findings.

Helical CT revealed cancer in 22 (88%) of 25 patients with proven prostate cancer. Transrectal sonographically guided biopsy detected 102 cancer sites in the peripheral zone and three in the transitional zone in these 25 patients. Helical CT accurately revealed 59 peripheral zone cancer sites (58%) but did not reveal 43 cancer sites (42%). Abnormal contrast enhancement in the peripheral zone that was not caused by cancer was seen in 10% of suspicious lesions. The three cancer sites in the transitional zone were indistinguishable from benign nodular changes.

Prostate cancer detected at transrectal sonographically guided biopsy appears on helical CT of the prostate as focal or diffuse areas of contrast enhancement in the peripheral zone. A prospective study has been initiated to determine the accuracy, sensitivity, and specificity.