Author(s): Starck M, Bohe M
OBJECTIVE: To compare digital examination, endoluminal ultrasound (ELU), and plain magnetic resonance imaging (MRI), with histopathological findings in the preoperative staging of rectal cancer. DESIGN: A prospective comparative study. SETTING: University hospital, Sweden. SUBJECTS: 35 patients with rectal cancer who presented during the period February 1987 to February 1991. RESULTS: The digital examination of 19 patients could be assessed and was correct in 13 (68%). ELU was done in 34 patients; the accuracy was 88%. Extension of tumour was overestimated in two and underestimated in two. MRI was done for 35 patients with an accuracy of 66%; in 12 patients extension was underestimated. The diagnostic accuracy of the assessment of lymph node involvement was 71% with ELU, and 72% with MRI. CONCLUSION: These findings indicate that MRI seems to underestimate the extension of rectal tumours, but both ELU and MRI can be helpful in selecting patients with advanced tumours for whom preoperative adjuvant treatment is being considered. ELU is superior in staging tumours confined to the rectal wall, and could be of value in the selection of patients whose tumours were suitable for local excision. None of these techniques, however, can reliably identify the extent of lymph node involvement.