An evaluation of lymphography in localized carcinoma of the prostate.

Lymph node biopsies were positive in 20% (7/35) of stage T1 and T2 (stage B) tumors and 64% (21/33) of stage T3 (stage C) tumors in 69 previously untreated and unselected patients with apparently localized carcinoma of the prostate. One patient with a To (stage A) tumor had no evidence of lymph node metastasis. Prospective analysis demonstrated an overall lymphographic accuracy of 78%, sensitivity of 57% and specificity of 92%. The detection of lymph node metastases in the lymphogram is limited by the frequency of microscopic metastasis and the frequency of benign changes within pelvic lymph nodes in this older patient population. Diagnostic criteria for metastatic disease which gives a low incidence of false-positive interpretations should be maintained, since relaxing the criteria will not necessarily improve the detection rate of metastases and would decrease specificity.