LIMITED EFFICACY OF PREOPERATIVE COMPUTED TOMOGRAPHIC SCANNING FOR THE EVALUATION OF LYMPH-NODE METASTASIS IN PATIENTS BEFORE RADICAL PROSTATECTOMY

Objectives. To evaluate the efficacy of preoperative computed tomograp hic (CT) scanning in patients with presumed localized prostatectomy pr ior to radical retropubic prostatectomy. Methods. A retrospective stud y of 173 consecutive patients believed to be candidates for radical re tropubic prostatectomy who underwent preoperative CT scanning regardle ss of preoperative prostate-specific antigen (PSA) value, clinical sta ge, or Gleason grade was undertaken. All patients underwent radical re tropubic prostatectomy with bilateral pelvic lymph node dissection or aspiration needle biopsy of abnormal nodes on CT scanning. Results. On e hundred sixty-five of 173 patients (95.4%) were believed to have nor mal CT scans preoperatively. Of these 165 patients, 156 (94.5%) were f ound to have negative lymph nodes confirmed histologically at the time of lymphadenectomy. Nine patients (5.5%) were found to have lymph nod e metastases confirmed histologically, despite a negative CT scan. Com puted tomographic scanning understaged 9 of 12 (75%) patients with pro ven metastases. Incidental abdominal pathology of clinical significanc e was documented in 4 patients (2.3%), including 2 with renal cell can cers, 1 with colon cancer, and 1 with a large (8 cm) abdominal aortic aneurysm. Prostate-specific antigen levels in patients with metastatic lymph nodes ranged from 0.7 to 130 ng/mL (Hybritech Tandem assay), wi th a mean level of 42 ng/mL. Although 9 of 33 patients (27.3%) with PS A levels greater than 25 ng/mL had node metastases, only 3 of these 33 patients (9.1%) were correctly diagnosed by CT scanning. Conclusions. Although additional numbers of patients with high PSA levels need to be evaluated, we could not find any justification for routine preopera tive CT scanning in patients with a PSA of less than 25 ng/mL. These r esults suggest that significant savings can be realized by abandoning the practice of routine CT scanning for lymph node metastasis in all p atients with newly diagnosed prostate cancer.