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Retroperitoneal lymph node staging of testicular tumours. TNM Study Group.

A prospective multicentre study was carried out to determine the efficiency of various diagnostic methods in the assessment of the retroperitoneal space. The diagnostic findings were confirmed histologically after retroperitoneal lymph node dissection (RLND). The sensitivity was 71% for bipedal lymphography, 41% for computed tomography (CT), 31% for abdominal ultrasound and 37% for alpha-fetoprotein/human chorionic gonadotrophin (AFP/HCG). Specificity was 60, 94, 87 and 93% respectively. When all diagnostic methods were combined, sensitivity was 88% and specificity 48%. The value of all methods depends on the metastatic enlargement of the lymph nodes. The predictive value of a negative diagnosis was 73% for lymphography, 67% for CT, 61% for ultrasound and 65% for AFP/HCG; the predictive value of a positive diagnosis was 58, 85, 69 and 81% respectively. Despite these results, lymphography is indicated only when a surveillance strategy is planned, since it detected 58% of the lymph node metastases that were overlooked by CT and tumour markers. Despite this, 17% of patients with clinical stage I tumours had metastases. False positive rates are detrimental to primary chemotherapy: between 24% (at least 2 methods positive) and 46% (1 or more methods positive) of patients with clinical stage II A/B tumours had a pathological stage I and for these patients primary chemotherapy meant overtreatment.