Endoscopic lymphoscintigraphy. A new tool for target surgery of rectal cancer.

To define the "in vivo" lymphatic drainage from the rectum and the anal canal, 79 subjects (normal controls and patients with rectal cancer) underwent endoscopic rectal lymphoscintigraphy. This method consists of endoscopically injecting a radiolabelled colloid into the rectal and anal submucosa. The diffusion of the tracer, which is drained preferentially by the lymphatic vessels, was determined by means of a computerized gamma camera. Our results suggest a different pattern of lymphatic drainage from the rectum as compared to traditional anatomical studies. Moreover, analysis of our data yields a new hypothesis about the lymphatic spread of rectal cancer. Therefore, lymphoscintigraphy could be employed in the preoperative assessment of "N" staging of these neoplasms. This should provide better selection of patients for different surgical approaches and for adjuvant therapy. The results of 2 years of experience and possible future applications of this technique are discussed.