ABSTRACT
Ten patients with colorectal cancer metastases received 125I-B72.3 and 131I-CC49 prior to laparotomy (five patients received 1 mg, and five 20 mg of each mAb). Tumor:serum ratios of 131I-CC49 were better than those of 125I-B72.3 (P < 0.01 at 1 mg; P = 0.05 at 20 mg; P < 0.01 at both doses). All known lesions > or = 1 cm in diameter were visualized at the 20 mg dose. There was no difference in absolute tumor uptake of 125I-B72.3 or 131I-CC49. We conclude that mAb CC49 has better relative uptake in colorectal cancers than mAb B72.3.
Subject(s)
Antibodies, Monoclonal/therapeutic use , Antigens, Neoplasm/immunology , Colorectal Neoplasms/radiotherapy , Glycoproteins/immunology , Immunoconjugates/therapeutic use , Iodine Radioisotopes/therapeutic use , Adrenal Gland Neoplasms/diagnostic imaging , Adrenal Gland Neoplasms/secondary , Adult , Aged , Antibodies, Monoclonal/pharmacokinetics , Colorectal Neoplasms/diagnostic imaging , Colorectal Neoplasms/pathology , Female , Humans , Immunoconjugates/pharmacokinetics , Iodine Radioisotopes/pharmacokinetics , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/secondary , Male , Middle Aged , Pelvic Neoplasms/diagnostic imaging , Pelvic Neoplasms/secondary , Radioimmunotherapy , Recurrence , Tomography, Emission-Computed, Single-PhotonABSTRACT
C110 is an anti-carcinoembryonic antigen murine IgG1 monoclonal antibody. Indium-111-labeled C110 radioimmunoscintigraphy (RIS) in colorectal cancer was studied in 51 presurgical patients at four institutions. Planar and SPECT images were obtained at least twice between 48 and 96 hr after injection of 5 mCi/5 mg of 111In-C110. Fifty-one patients had 87 biopsy-proven lesions at surgery (57 hepatic, 30 extra-hepatic). Thirty-three patients (64.7%) had positive radionuclide scans, while 32 (62.8%) had positive CT scans (p = NS). While CT was better at overall lesion detection (62.1% versus 56%, p < 0.05), radionuclide scans were better than CT for extra-hepatic disease (60% versus 46.7%, p < 0.01). Hepatic metastases (52.6%) were visualized by Mab scans to selectively concentrate radioactivity. Uptake in draining lymph nodes was a significant limitation, making evaluation of these sites difficult. Indium-111-C110 shows selective uptake in metastatic colorectal cancer, including more than half of all hepatic lesions evaluated.
