Molecular imaging is a disease-specific targeting modality that promises much more accurate diagnoses of serious diseases such as cancer and infections. Agents are being continually developed with a view to clinical translation, but a crucial step in the development process is the evaluation of agents in preclinical animal models of human diseases. Therefore, tissue pharmacokinetic studies and positron emission tomography imaging are among the most important tools used to study prospective new ligands. Evaluation of agents yields a final measurement in terms of percent injected dose per gram of tissue, normalized to the initial injected dose.
Reproducible accuracy is completely dependent on measurement of the initial injected dose per animal. Currently, there is no way of accurately measuring the injectable dose of small amounts of radioactivity used in many pre-clinical tracer studies, as on-the-market commercial dose calibrators measure at too high a dose range, typically at 10-1000 µCi and higher. Using such commercial calibrators to estimate micro-doses (0.01-10 µCi) results in unavoidable and up to ± 20% measurement errors.
To solve the problem of measuring small doses of radioactivity, and without the need of a volumetric correction, a scientist at the NCI Frederick National Laboratory for Cancer Research working at the NCI Molecular Imaging Program invented a device (see images below) that can accurately measure radioactivity doses between 0.1-100 μCi with 1% error. The device is a working prototype and requires collaboration to produce calibration standards. NCI seeks parties to commercialize this technology through collaborative co-development or licensing.
- Radioligand cell binding studies
- Bio-distribution pre-clinical studies Immune cell cancer therapy
- Measure small doses between 50 nCi (1.8 kBq) and 100 µCi (3.7 MBq) with 1% accuracy
- Measure volumes of activity up to 20cc without volumetric correction to 1% accuracy
Stephen S. Adler (FNLCR)
- U.S. Patent Filed: U.S. Patent Application Number 62/554,980, Filed 06 Sep 2017