[Reasonable lymph node dissection in radical gastrectomy for gastric cancer: introduction of computer information system and lymphography technique by India-ink].

A computer information system was developed and clinically used in National Cancer Center Tokyo in 1983. Seven data of an individual patient are preoperatively input in the system: sex, age, location, macroscopic type, maximal diameter, depth of invasion, and histological type of biopsy. After the data-analysis of 3,785 patients, the computer outputs three data; expected five year survival rate, each metastatic rate of 16 regional lymph nodes, and types of recurrence. Plan of lymph node dissection can reasonably be decided by this report. 0.5ml of India-ink (CH-40) is injected in the perigastric lymph nodes, and it stains all lymphatic channels from the injection points in black. Using the technique, systematic dissection can be performed easily and completely. After the introduction of these systems, five year survival rate was improved from 90.0% to 95.5% in Stage I, from 76.0% to 81.6% in Stage II, from 51.1% to 56.8% in Stage III, and from 12.9% to 16.6% in Stage IV.