Jered Christopher Garrison PhD, Presenter: Nothing to Disclose

Tammy L. Rold MS, Abstract Co-Author: Nothing to Disclose

Gary L. Sieckman MS, Abstract Co-Author: Nothing to Disclose

Said Daibes Figueroa PhD, Abstract Co-Author: Nothing to Disclose

Lixin Ma PhD, Abstract Co-Author: Nothing to Disclose

Wynn A. Volkert PhD, Abstract Co-Author: Nothing to Disclose

Timothy J. Hoffman PhD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

The evaluation of a variety of receptors in neoplastic tissues has revealed an increased receptor expression of certain receptors relative to normal tissues. The BB2 receptor, a receptor subtype of the Bombesin receptor family, has been shown to be present in a variety of cancers. BB2 receptor positive tumors have been detected in biopsies of prostate (68-100% occurrence), breast (61-63% occurrence) and small-cell lung (30% occurrence) cancers thereby validating the BB2 receptor as a potential molecular target. Our group and others have focused on designing BB2 receptor-avid peptides as molecular imaging agents for use in PET and SPECT modalities. This poster will focus on our current efforts in the design of PET and SPECT BB2 receptor-avid molecular imaging agents.

The receptor-avid peptides were synthesized using solid phase peptide synthesis. The peptides were radiolabeled with a variety of SPECT (99mTc, 111In and 177Lu) and PET (64Cu) radionuclides. The peptides were purified using HPLC and prepared for in vivo studies. In vivo studies were performed using prostate, breast and small-cell lung tumor bearing SCID mouse model. SPECT/CT, PET/CT and MRI imaging was performed at 1, 4 and 24hr post-injection in order to determine optimum target to non-target imaging times.

All BB2 receptor-avid peptides demonstrated in vivo receptor-mediated uptake into the tumor xenografts. Imaging quality correlated with the pharmacokinetic clearance of the BB2 receptor-avid peptides from the non-target tissues. Optimal visualization of the tumors was achieved between 4 – 18 hr post-injection, depending on the receptor-avid peptide employed. Tumors to background ratios were, typically, found to be greater in the prostate cancer xenograft mouse model.

The BB2 receptor-avid peptides studied demonstrated significant potential for clinical use as cancer detection molecular imaging agents for prostate, breast and small-cell lung cancer.

The BB2 receptor-avid peptides studied demonstrated significant potential for clinical use as cancer detection molecular imaging agents for prostate, breast and small-cell lung cancer.

Garrison, J, Rold, T, Sieckman, G, Daibes Figueroa, S, Ma, L, Volkert, W, Hoffman, T, et al, , et al, , Prostate, Breast, and Small-Cell Lung Cancer Detection Using Targeted PET and SPECT Molecular Imaging Agents.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5011716.html