Radioimmunodetection of non-small cell lung cancer using technetium-99m-anticarcinoembryonic antigen immu-4 fab′ fragment

Abstract

Background. Although computed tomography and magnetic resonance imaging have improved the staging and evaluation of non‐small cell lung cancer (NSCLC), mediastinal staging lacks adequate specificity and sensitivity. Radioimmunodetection may augment computed tomography and magnetic resonance imaging. The authors evaluated the ability of the technetium 99m‐anticarcino‐embryonic antigen IMMU‐4 Fab′ fragment to localize NSCLC in vivo, measured its pharmacokinetics, and estimated its radiation dose. Methods. Seventeen patients with carcinoembryonic antigen‐positive NSCLC received 16–30 mCi of technetium 99m IMMU‐4 Fab′. Planar imaging was performed at 1–7 hours and 20–24 hours. Single‐photon emission computed tomography (SPECT) was performed within 8 hours after injection. In 10 patients, blood sampling, urine collection, and quantitative imaging were performed to determine blood and urine pharmacokinetics and radiation dose estimates. Human anti‐mouse antibody response was measured for as long as 3 months after administration. Results. Planar and/or SPECT imaging detected 72% of 32 known lesions. SPECT was more sensitive than planar imaging. T½ohα averaged 0.18 ± 0.33 hours; T½ohβ averaged 8.02 ± 5.53 hours. The mean concentration versus time value was 1.11 ± 0.56 mg.h. The average whole body dose estimated for administration of 30 mCi was 0.45 ± 0.08 rads. No human anti‐mouse antibody responses were detected. Conclusion. The tumor detection rate was high, but the persistent blood pool at < 8 hours complicated image interpretation. An intermediate imaging time point (12–16 hours) might be preferable. SPECT is an important adjunct to imaging with this radioimmunoconjugate. The acceptable dosimetry estimated for 30 mCi Technetium 99m IMMU‐4 Fab′ and the lack of human anti‐mouse antibody responses suggest this is a promising localizing tool for NSCLC. Cancer 1994; 73:890–5.

Staging intrathoracic non-small-cell lung cancer

“…The sensitivity and specificity for metastatic mediastinal lymphadenopathy was of the order of 80 %. There have also been encouraging initial reports concerning the use of SPECT with technetium-99m radiolabelled monoclonal antibodies [108][109][110][111], and thallium-201 [112] for evaluating nodal metastases. Studies using the murine monoclonal antibody NR-LU-10 have found sensitivities of the order of 90 % [108], and recently a group using thallium-201 in more than 100 patients reported a sensitivity of over 75 % [112].…”