Correlation of Prostate-Specific Antigen and Technetium-99m HMDP Bone Imaging

For an evaluation of the clinical utility of prostate-specific antigen (PSA), 32 prostatic carcinoma patients (ages 54-76) and 13 nonprostatic carcinoma patients (ages 60-70) underwent PSA measurements and bone imaging. At the time of bone imaging, each patientʼs PSA value was measured by a monoclonal immunoradiometric assay. All 13 nonprostatic carcinoma patients (11 bronchogenic, 1 colon, and 1 urinary bladder) gave normal PSA values, although 6 had metastatic bone disease. The 32 prostatic cancer patients were divided into 2 groups of 16 each; PSA levels in Group 1 were abnormal (≥ng/ml)PSA levels in Group 2 were normal (< 4 ng/ml). In Group 1, bone images of 14 patients showed bone metastases; 6 of the 14 showed progression of metastases in a 6- to 12-month period. Two patients in Group 1 were negative for skeletal metastases. Twelve patients in Group 2 were negative for skeletal metastases; bone imaging in 1 showed regression of skeletal metastases; and 3 patients had unchanged bone lesion(s). The data indicate that PSA measurements may enhance bone imaging interpretation and provide valuable clinical monitoring of prostatic carcinoma. In the case of a patient with positive bone imaging and an unknown primary, PSA measurements may definitively determine if metastases originated from prostatic carcinoma.