RETROPERITONEAL IMAGING WITH 3RD AND 4TH GENERATION COMPUTED AXIAL-TOMOGRAPHY IN CLINICAL STAGE-I NONSEMINOMATOUS GERM-CELL TUMORS

Objectives. To examine the accuracy rate of abdominal staging using th ird and fourth generation computed tomography (CT) scanning in clinica l Stage I testicular nonseminoma patients. Methods. Between January 19 85 and August 1993, 57 patients presented to our center with clinical Stage I testicular nonseminoma. Retroperitoneal computed tomographic s taging studies were interpreted to be normal preoperatively in the ent ire group. In addition, tumor marker values were normal or returned to normal postorchiectomy within the appropriate half-life intervals. Al l patients were subjected to radical or modified retroperitoneal lymph node dissection (19% and 72%, respectively). Original abdominal CT sc ans (preretroperitoneal lymph node dissection) were available for blin ded retrospective re-review in 16 cases (7 pathologic Stage II, 9 path ologic Stage I). Results. Nineteen of 57 (33%) patients were upstaged at surgery including 6 patients (11%) who demonstrated II B volume dis ease. Third and fourth generation CT scanning of the retroperitoneum y ielded a 66% accuracy rate in this population. Six out of 7 pathologic Stage II pre-lymph node dissection abdominal CT scans that were avail able for blinded re-review revealed nonpathologic nodes by size criter ia in the primary landing zone for the corresponding original tumor. C onclusions. Our data suggests that for clinical Stage I nonseminoma in the 1985 to 1993 era, undue reliance was placed on a less than ideal staging test. The 33% false-negative rate reported showed no improveme nt over earlier reports and reaffirms concern for relying solely on th ird or fourth generation CT imaging of the retroperitoneum in the stag ing of clinical Stage I nonseminomatous germ cell tumor (NSGCT) patien ts. The presence of any number of lymph nodes in the expected primary landing zone, regardless of size, should raise serious suspicion for o ccult nodal disease.