Benjamin Titz PhD, Presenter: Employee, Cellectar Biosciences, Inc.

John S. Kuo MD, PhD, Abstract Co-Author: Nothing to Disclose

Kevin Robert Kozak MD, PhD, Abstract Co-Author: Officer, Cellectar Biosciences, Inc

Perry J. Pickhardt MD, Abstract Co-Author: Co-founder, VirtuoCTC, LLC Stockholder, Cellectar Biosciences, Inc

Joseph Grudzinski MS, Abstract Co-Author: Employee, Cellectar Biosciences, Inc

Jamey Paul Weichert PhD, Abstract Co-Author: President, Cellectar, LLC Chairman, Cellectar, LLC

Lance T. Hall MD, Abstract Co-Author: Nothing to Disclose

MR imaging of primary brain tumors has limited value for assessing the extent of tumor infiltration and differentiating tumor recurrence from pseudoprogression. Molecular imaging has the potential to overcome these limitations. CLR1404 is a novel alkylphosphocholine analogue characterized by preferential uptake and prolonged retention in cancer cells and cancer stem cells. Here, we report on the first-in-human use of 124I-CLR1404 PET/CT in primary and recurrent glioma.

4 patients with low grade and 7 patients with high grade glioma were injected with 74 or 185 MBq of 124I-CLR1404 and imaged with PET/CT at 6, 24, and 48 hrs post-infusion. The majority of patients (10/11) had suspected recurrent disease. In patients with uptake above background, tumor to background ratios (T:B) were generated and T1 MRI-Gad+ volumes, SUV threshold volumes (1.0, 1.2), and T:B ratio threshold volumes (1.6, 2.0) were segmented. In addition, T:B lesion kinetics were analyzed.

124I-CLR1404 PET demonstrated avid tumor uptake above background in 7 of 11 patients. Three low grade gliomas and one high grade did not show uptake. With clinical follow-up, two of the three low grade gliomas and the high grade glioma were shown to be pseudoprogression and not tumor recurrence. In positive patients, uptake was observed both in areas with and without Gadolinium enhancement on MRI. There was no significant uptake in normal brain. Maximum T:B ratios were 11.3±3.9 at 24 hrs (range 5.7-15.6) and 10.8±2.9 at 48 hrs (range 6.4-14.0). Average tumor volumes (in mL) were 4.6 (range 0.2-7.6) for Gad+ MRI, 59.1 (range 33.6-91.0) for PET T:B1.6, 47.2 (range 28.8-66.3) for PET T:B2.0, 17.4 (range 5.1-35.3) for SUV1.0, and 12.3 (range 1.7-28.7) for SUV1.2.

124I-CLR1404 PET/CT successfully images glioma and demonstrates high tumor-to-background contrast and larger lesion volumes than contrast-enhanced MRI. 124I-CLR1404 PET provides tumor-specific molecular imaging that may be valuable for the identification of tumor margin and the differentiation of treatment related changes from tumor progression.

124I-CLR1404 PET/CT demonstrates differential, high contrast uptake as well as larger lesion volumes than CE MRI in glioma and may help distinguish treatment related changes from disease progression.

Titz, B, Kuo, J, Kozak, K, Pickhardt, P, Grudzinski, J, Weichert, J, Hall, L, Prospective Evaluation of 124I-CLR1404 PET/CT in Glioma.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14001696.html