THE INTRAOPERATIVE DETECTION OF OVARIAN ADENOCARCINOMA USING RADIOLABELED CC49 MONOCLONAL-ANTIBODY AND A HAND-HELD GAMMA-DETECTING PROBE

A phase II study to evaluate the safety and efficacy of the I-125-radi olabeled anti-TAG-72 monoclonal antibody, CC49, as a component of a sy stem for the intraoperative detection of occult ovarian cancer deposit s was carried out at the University of Nebraska Medical Center. Patien ts entered into the,study were to have surgery for evaluation of their disease status. The primary objective of this study was to determine the ability of a gamma-detecting probe (GDP), the Neoprobe(R)1000, to intraoperatively localize sites of disease not identified by tradition al surgical or radiographic evaluation. It was postulated that improve d detection of cancer foci might allow for therapeutic excision or mig ht result in an alteration of subsequent treatment. Ten patients were enrolled in the study between May 1993 and March 1994. Nine of the pat ients were undergoing second-look surgery after completing primary che motherapy. The remaining patient was having surgery to assess possible cancer recurrence All patients received an intravenous injection of 2 mCi/1mg I-125-radiolabeled CC49 without complication. After a mean of 24.5 days. the patients' background radiation counts were deemed low e nough for accurate intraoperative cancer localization, and surgery was performed Anl, visibly or palpably abnormal areas were biopsied after being evaluated with the GDP. Arty areas suspicious for malignancy by GDP evaluation were also biopsied. Two patients without evident disea se by radiographic or surgical examination had histologically confirme d metastases localized by the GDP. Four patients had obvious disease a t surgery which was variably confirmed by the GDP; two of these patien ts had baseline elevations in circulating TAG-72 antigen levels that m ay have affected binding of antibody to the tumor. This system of radi oimmunoguided surgery was well tolerated and practical in its applicat ion, and it permitted disease detection that resulted in potentially b eneficial changes in patient management.