New diagnostic imaging in rectal cancer: endosonography and immunoscintigraphy.

Endosonography of the rectum, combining the advantages of both endoscopy and sonography, provides information not at present available from other imaging modalities. It is remarkably accurate in the pre-operative assessment of tumor penetration. In the evaluation of lymph nodes, the specificity and sensitivity is 83% and 72%, respectively. For the detection of local recurrence in asymptomatic patients promising results can be obtained. In contrast, the potential benefits of immunoscintigraphy in patients with rectal cancer have yet to be determined but preliminary results indicate that immunoscintigraphy in combination with endosonography may assist the surgeon in confirming or excluding the suspicion of recurrence.