RI lymphography by submucous injection in the pars vaginalis of the cervix uteri.

We have improved conventional RI lymphography, and investigated its usefulness as a screening method for lymph node metastasis. We injected 99mTc-sulfur colloid directly under the mucous membrane of the pars vaginalis of the cervix uteri of patients with cervical cancer, and took images every 5 minutes for 2 hours. At the same time, we analyzed the data stored in a computer, and attempted to observe the movement of radioisotopes taken into the lymph nodes. The subjects were 100 patients (200 study units) with cervical cancer, on whom histological examinations were performed. Of these, 41 study units were seen to be clouded by invasive cancer in the lymph nodes or parametrium. In the group in which both lymph nodes adjacent to the uterine cervix and the common iliac lymph nodes were delineated, lymph node metastasis was ruled out in 96.2%. Also, in some of the cases in which metastasis was seen, even though the lymph nodes were delineated, there was some delay in taking up the isotope. Therefore, it seems that as the main method, a diagnosis of "true negative" in the case of no metastasis is more useful than a "true positive" for the existence of metastasis.