Research & Industry Reports

Molecular Imaging of Lymphoma Using a Novel LFA-1 Targeted Radiopharmaceutical.

By Jeffrey P. Norenberg, University of New Mexico

A novel LFA-1 targeted small-molecule radiopharmaceutical has been successfully radiolabeled with 177Lu, 213Bi, and 90Y at UNM. It has been demonstrated this novel LFA-1 targeted small-molecule radiopharmaceutical has a high affi nity for the Leukocyte-Activating-Factor (LFA-1) receptors characteristic of lymphoma, but which are not expressed on non-hematopoetic cells.

To evaluate the in vivo molecular imaging potential of this compound in a mouse model of lymphoma. The radiometal 111In was incorporated into novel LFA-1 targeted small-molecule radiopharmaceutical. Incorporation yield was determined using ITLC and HPLC.

Mice were imaged with the Bioscan NanoSPECT/CT imaging system at 0.5, 2 and 24 hours post injection. Images are individually shown below. ITLC analyses of novel 111In-labeled LFA-1 targeted small-molecule radiopharmaceutical demonstrated > 98% incorporation yield. The specific activity achieved was 473 Ci/mmol. Images with 111In-labeled novel LFA-1 targeted small molecule radiopharmaceutical show focal uptake in the liver and lymph, the sites of known metastasis.

These data shows that the LFA-1 targeted radiopharmaceutical is a highly selective imaging probe, demonstrating high sensitivity and specificity for in vivo SPECT/PET imaging sites of infection.

Because of the rapid targeting and clearance, the radiation absorbed dose to patient’s receiving this novel 111In-labeled LFA-1 targeted radiopharmaceutical will be low. The 111In-labeled novel LFA-1 targeted small-molecule radiopharmaceutical demonstrates rapid targeted uptake consistent with molecular targeting of LFA-1 expression in lymphoma.