Use of a medical decision support system to improve the preoperative diagnosis of prostate cancer with pelvic lymph node metastases.

BACKGROUND: We evaluated the effects of a medical decision support system on the preoperative diagnosis of prostate cancer with pelvic lymph node metastases. METHODS: The preoperative accuracy of staging prostate cancer with pelvic lymph node metastasis by the prostate cancer expert system (PCES) for 43 patients was compared to the accuracy of staging performed by 2 urological attending physicians and 5 residents, to test the validity of the PCES. The effect of PCES consultation on physicians' staging for prostate cancer with pelvic lymph node involvement was evaluated. RESULTS: In the diagnosis of prostate cancer with pelvic lymph node metastasis, PCES was significantly more accurate than the two attending physicians alone (p = 0.042; p = 0.008). All the urological residents' diagnoses were significantly less accurate than those of the PCES. After PCES consultation, all the urological residents increased diagnostic specificity significantly. Most residents usually used PCES for consultation only after the attending physician or department asked for the results. CONCLUSION: Owing to an increased ability for preoperative diagnosis of prostate cancer with pelvic lymph node metastasis, as supported by the PCES, some unnecessary pelvic lymphadenectomies may be avoided.