Accuracy and cost of intraoperative lymph node frozen sections at radical prostatectomy

Aim-To assess the value of intraoperative diagnostic examination of frozen sections of lymph nodes removed during radical prostatectomy. Methods-Pelvic lymph nodes from patients with prostatic carcinoma were obta ined (1) as frozen sections during radical prostatectomy, to exclude patien ts from non-curative surgery and (2) as paraffin sections postoperatively f rom lymphadenectomy performed at radical prostatectomy, to stage the tumour and assess need for adjuvant treatment. Findings from the two approaches w ere used to assess the accuracy and cost of frozen section diagnosis, and t o judge the results of omitting intraoperative diagnosis. Results-In 82 patients frozen section revealed metastasis in six (7.3%), an d metastases were found in a further four (4.9%) on paraffin sections (fals e negatives). Of the 195 patients undergoing staging lymphadenectomy (witho ut frozen section), metastatic cancer was seen in nine cases (4.6%). The fr ozen section cost of metastatic cancer detection per patient was calculated as pound 7516 (pound 550 x 82/6), with an associated false negative rate o f 33%. Conclusions-Frozen section diagnosis of metastatic carcinoma in pelvic lymp h nodes before radical prostatectomy has a high false negative rate and is costly. It may not be justified with the observed low incidence of lymph no de metastasis.