Using a prostate exam simulator to decipher palpation techniques that facilitate the detection of abnormalities near clinical limits.

INTRODUCTION: Prostate carcinoma (and other prostate irregularities and abnormalities) is detected in part via the digital rectal examination. Training clinicians to use particular palpation techniques may be one way to improve the rates of detection.

METHODS: In an experiment of 34 participants with clinical backgrounds, we used a custom-built simulator to determine whether certain finger palpation techniques improved one's ability to detect abnormalities smaller in size and dispersed as multiples over a volume. The intent was to test abnormality cases of clinical relevance near the limits of size perceptibility (ie, 5-mm diameter). The simulator can present abnormalities in various configurations and record finger movement. To characterize finger movement, four palpation techniques were quantitatively defined (global finger movement, local finger movement, average intentional finger pressure, and dominant intentional finger frequency) to represent the qualitative definitions of other researchers.

RESULTS: Participants who used more thorough patterns of global finger movement (V and L) ensured that the entire prostate was searched and detected more abnormalities. A higher magnitude of finger pressure was associated with the detection of smaller abnormalities. The local finger movement of firm pressure with varying intensities was most indicative of success and was required to identify the smallest (5-mm diameter) abnormality. When participants used firm pressure with varying intensities, their dominant intentional finger frequency was about 6 Hz.

CONCLUSIONS: The use of certain palpation techniques does enable the detection of smaller and more numerous abnormalities, and we seek to abstract these techniques into a systematic protocol for use in the clinic.