Leibovici D et al. (2005) Transrectal ultrasound versus magnetic resonance imaging for detection of rectal wall invasion by prostate cancer. Prostate 62: 101–104

Extensive pelvic surgery, including total pelvic exenteration (TPE) or cystoprostatectomy, is used as a palliative treatment in some patients with locally advanced prostate cancer. The success of this approach relies on the accurate assessment of the extent of invasion into the bladder or rectum. It is not clear, however, which imaging modality is the most appropriate. In a recent study, Leibovici et al. have compared two common methods—transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI)—in the detection of rectal wall involvement.

This retrospective study included 40 men who had undergone TPE (n = 16) or cystoprostatectomy (n = 24) as salvage therapy for locally advanced prostate cancer. The patients were assessed preoperatively using TRUS, MRI or both. The sensitivity and specificity of the two methods were calculated with reference to histologic findings, positive surgical margins or recurrence of disease in the rectal wall during a median follow-up of 18.6 months.

Although MRI had specificity of 100% for the detection of rectal wall involvement, its sensitivity was low at 55% and so this method is associated with a risk of false-negative results. In contrast, TRUS was highly sensitive (93%) and fairly specific (87%), with an overall accuracy of 89%.