Role of radioimmunoguided surgery using iodine-125-labeled B72.3 monoclonal antibody in gastric cancer surgery.

Uniform and accurate staging of gastric cancer is essential to predict prognosis and assess the effectiveness of treatment strategies. An appropriate amount of surgical resection of the primary tumor and lymph node dissection appears to be fundamental for such staging. In seven out of 10 patients who were candidates for curative surgery, we assessed the usefulness of radioimmunoguided surgery (RIGS) using B72.2 monoclonal antibody (MoAb) labeled to Iodine-125 (I125) for the intraoperative staging of the tumor and the first (N1) and second echelon (N2) lymph nodes. We obtained a correct RIGS identification of primary lesions in four out of seven patients (57.1%), while lymph node staging assessment showed positive results in two out of four patients with lymph node metastases. RIGS correctly identified 26/ 40 (65%) metastatic nodes of these last two patients. RIGS intraoperative staging of gastric cancer--which may be essential for the assessment of the extension of the primary resection and to modulate lymph node dissection--was unsatisfactory. We believe that other technical approaches and more specific MoAbs should be evaluated for RIGS purposes in gastric cancer surgery.