title: Immunoscintigraphy with 99Tcm-labelled monoclonal anti-CEA BW 431/26 antibodies in patients with suspected recurrent and metastatic colorectal carcinoma: two-year follow-up.
abstract: The aim of this study was to evaluate immunoscintigraphy with BW 431/26 anti-CEA antibody in the follow-up of 15 patients with colorectal carcinoma. A whole-body scan followed by SPET imaging of the abdomen and pelvis was performed 4-6 and 20-24 h after the intravenous infusion of 0.6-1.0 mg of intact anti-CEA monoclonal BW 431/26 antibody labelled with 814-1110 MBq of 99Tcm. The HAMA response and serum CEA levels were determined. Immunoscintigraphic findings were verified by biopsy, radiologically and/or by 2 year follow-up. On an individual patient basis, immunoscintigraphy demonstrated an overall sensitivity of 83%, specificity of 100%, accuracy of 87%, positive predictive value of 100% and negative predictive value of 60%. Better results were achieved in the pelvic region than in the liver or in the extra-hepatic abdominal region. We evaluated 40 lesions; on an individual lesion basis, immuno-scintigraphy gave a sensitivity of 80% and an accuracy of 80%. SPET images detected significantly more lesions than whole-body planar images (P < 0.05). SPET at 20-24 h detected significantly more 'hot' lesions than at 4-6 h (P < 0.01). No correlation between CEA serum levels and immunoscintigraphy was observed (r = 0.376, P > 0.05). One of nine patients (11%) developed HAMA after immunoscintigraphy. We conclude that immunoscintigraphy with BW 431/26 antibody appears able to differentiate between tumour recurrence and scar tissue, and to evaluate liver metastases of colorectal carcinoma. Serum CEA levels appear not to influence the result of immunoscintigraphy and the HAMA response is minimal. A delayed SPET scan should be part of an immunoscintigraphic imaging protocol when 99Tcm-labelled BW 431/26 monoclonal antibody is used.
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Sestre Milosrdnice, Zagreb, Croatia. miodraglacic@public.srce.hr
authors.forename: M
authors.initials: M
authors.lastname: Lacić
authors.forename: T
authors.initials: T
authors.lastname: Bokulić
authors.forename: J
authors.initials: J
authors.lastname: Lukac
authors.forename: R P
authors.initials: RP
authors.lastname: Baum
authors.forename: Z
authors.initials: Z
authors.lastname: Kusić
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen / Q000097:blood / Q000276:immunology*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D010388:Pelvis / Q000000981:diagnostic imaging; D019275:Radiopharmaceuticals; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D019275:Radiopharmaceuticals