[Iodine-125 labeled monoclonal antibody 3H11: in radioimmunoguided surgery for primary gastric cancer].
OBJECTIVE
To evaluate the clinical usefulness of iodine-125 labeled monoclonal antibody (MAb) 3H11 in radioimmunoguided surgery (RIGS) for patients with gastric cancer.


METHODS
Thirty-five patients with primary gastric cancer were enrolled. Via endoscopy, iodine-125 labeled MAb 3H11 was injected into submucosa around the tumor. All patients underwent surgery 4 to 11 days after administration. Intraoperative radioimmunodetection was performed using a hand-held gamma-detecting probe. The counts of target sites were obtained, and tumor-to-normal tissue (T/NT) ratios were calculated. The T/NT ratio of 3.5:1 was taken as the lowest threshold value of positive gastric wall infiltration, and 3.0:1 for lymph node metastasis. Serial sections of those RIGS-positive lymph nodes, which were originally diagnosed as negative by routine histology, were made. Immunohistochemical staining was performed to detect the existence of lymphatic micrometastasis.


RESULTS
Of thirty-five patients, 33 underwent RIGS successfully. The accuracy rate in detecting tumor infiltration of the incision margins was 97.0%, and the specificity 98.5%. In the group of patients with an interval of 6 to 8 days between injection and operation (n = 25), the RIGS results were satisfying. For the detection of lymphatic metastasis, the sensitivity of RIGS was 83.6%, the specificity 95.0%, and the accuracy 91.3%. The existence of lymphatic micrometastasis were verified immunohistochemically in 52.6% (10/19) of those RIGS positive but histologically negative lymph nodes.


CONCLUSIONS
This study validates the use of iodine-125 labeled monoclonal antibody 3H11 for the intraoperative detection of carcinomatous lesions in gastric cancer.
Wang
C
C
Department of Surgery, Clinic Neoplasms College, Beijing Medical University, Beijing 100036, China.
Wang
Y
Y
Su
X
X
Lin
B
B
Xu
X
X
Zhang
M
M
Li
J
J
Xu
G
G
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging; D016719:Radioimmunodetection / Q000379:methods*; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*
D000911:Antibodies, Monoclonal; D007457:Iodine Radioisotopes