Ecografía transrectal y tacto rectal en la estimación del volumen prostático. Aplicación a la práctica clínica

Abstract

ObjectiveTo compare the accuracy of rectal examination and transrectal ultrasound for classifying patients for endoscopic resection or retro-pubic prostatectomy. Material and methodsA retrospective analysis was performed on a total of 133 patients who underwent radical prostatectomy for prostate cancer, collecting data on the ultrasound prostatic volume, the volume of the surgical specimen, and prostate size in digital rectal examination.Patients that had previously undergone prostatic transrectal resection, taking androgen treatment, and who had received radiotherapy, were excluded.Digital rectal examination and ultrasound prostatic volume were divided into 2 categories (I-II and III-IV, and <70 and >70 cc, respectively).To analyse the accuracy of both tests, the areas under the ROC (receiver operating characteristic) curve were compared, using the volume of the surgical specimen as the reference standard.The differences between the 2 methods were analysed using the Hanley-McNeil test. ResultsIn approximately 90% of cases, the volume of most of the pieces was <70 cc, prostate size in digital rectal examination was I-II, and using ultrasound the volume was <70 cc.The association between prostate volume estimated by digital rectal examination and volume of surgical specimen achieved an area under the curve of 0.69 (P=.03), whilst it was 0.77 (P=.001) between transrectal ultrasound and volume of surgical specimen. The differences between the 2 methods were not statistically significant (P=.38). ConclusionsOur study results show that the transrectal ultrasound does not significantly increase the classification capacity of digital rectal examination.