[Transrectal ultrasonography in the study of recurrences in patients surgically treated for rectal neoplasms]

The value of transrectal US is known in the preoperative staging of rectal cancer but remains debated in the follow-up of the patients submitted to anterior resection or local therapy. The authors report their experience with the postoperative follow-up of 80 patients submitted to 125 transrectal US exams to study method reliability. The results were 9 true positive, 2 false positive, 113 true negative and 1 false negative cases, with 90% sensitivity, 98.3% specificity and 97.6% accuracy rates. Positive predictive value was 81.8% and negative predictive values was 99.1%. Twelve patients were submitted also to MRI which correctly diagnosed one false negative result of transrectal US. Twenty-one patients were examined also with transrectal Doppler and color-Doppler US: in rectal cancer recurrences the peak velocity of hemorrhoid vascular flow was higher than in non-recurrent patients. On the basis of our results, transrectal US deserves to be included in the postoperative follow-up of the patients submitted to anterior resection or to local therapy for rectal cancer. Moreover, according to our preliminary findings, Doppler and color-Doppler US can improve transrectal US reliability in detecting local recurrences.