Preliminary experiences in radioimmunoguided surgery for primary lung neoplasms

Background. Radioimmunoguided surgery (RIGS) can be a valid option in the management of lung cancer as well as neoplasms in other anatomic sites. Methods. We evaluated the usefulness of radioimmunoguided surgery (RIGS) in the staging of primitive non small cell lung cancer. Intraoperatively, this technique can define the lymph nodes involvement and thus, the radicality of the resection. In the first stage of our study, we looked for the epitope TAG 72 in 45 patients with primary non small cell lung cancer. The epitope was found by immunochemistry in only 6 cases. The only one operable patient was injected with monoclonal antibody B 72.3, that was125I-labelled. Results. At the operation, the monoclonal antibody showed no selectivity for neoplastic cells. Neoplastic tissue and healthy tissue showed a similar detection of the monoclonal antibody both intraoperatively and at the histochemical study. Because of the problems related with this method - e.g. technical difficulties, excessive wasting of time and lack of imaging - we modified our strategy. In this second stage of our study we used fragments of murine anti-CEA monoclonal antibody F023C5. The protocol was performed in 11 patients with squamous cell lung cancer. In one patient operated on for an excavated cancer (not well-defined at the immunoscintigraphy) intraoperative detection was negative while the ex vivo counts were significant: the neoplastic tissue showed a radioactivity twice higher than healthy tissue. Furthermore, the RIGS found a small intraparenchimal lymph node that was seen neither by CT nor by immunoscintigraphy. Conclusions. Our data are still preliminary, but with improvement of the technique and the use of more specific monoclonal antibodies the RIGS could become a helpful method, able to improve the radicality of surgery for lung cancer.