Transrectal ultrasonography in prostatic cancer: interexaminer variability of interpretation.

Objective: To compare the variability of transrectal ultrasonographic (TRUS) interpretation for the decision of performing biopsies and the lesions to biopsy.

Methods: We extracted at random from our videotape database 16 records of patients who had undergone biopsies, added 2 normal glands and duplicated 2 of these 18 records. Based on the records, 5 well-trained physicians had to describe the images on the tape, and to decide whether or not to biopsy the prostate. A kappa test was computed between each couple of readers, and for the whole group. The kappa test denotes the agreement between examiners. A value of kappa < 0.20 is considered poor to slight agreement, 0.2-0.40 is considered fair agreement.

Results: The agreement between the 5 readers was poor for the biopsy decision (kappa < 0.2) and the difficulty to read the records (kappa = 0.05). The results with the global kappa were similar with a highest value < 0.3. Most of the abnormalities were described in the peripheral zone. The global kappa for the seminal vesicles interpretation is poor, but better for the capsular penetration.

Conclusion: TRUS has a poor informative value between different practitioners. This poor agreement between different practitioners must lead to more objective ultrasonographic methods.