RT Journal Article
SR Electronic
T1 Shortwave infrared detection of medical radioisotope Cerenkov luminescence.
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP jnumed.122.264079
DO 10.2967/jnumed.122.264079
A1 Ben Mc Larney
A1 Qize Zhang
A1 Edwin C. Pratt
A1 Magdalena Skubal
A1 Elizabeth Isaac
A1 Hsiao-Ting Hsu
A1 Anuja Ogirala
A1 Jan Grimm
YR 2022
UL http://jnm.snmjournals.org/content/early/2022/06/23/jnumed.122.264079.abstract
AB Rationale: Cerenkov luminescence (CL) is produced by medical radioisotopes when charged particles (β+/-) travel faster than light in a dielectric medium (e.g. tissue). CLs blue-weighted luminescence is continuous and decreases proportional to wavelength. CL imaging (CLI) is an economical PET alternative, but heavily limited by the optical properties (scattering, absorption and special setup requirements). Shortwave infrared (SWIR, 900 – 1700 nm) CL has been detected from linear accelerators operating at MeV ranges but not from from medical radioisotopes. Methods: Indium gallium arsenide (InGaAs) focal plane arrays and SWIR lenses were mounted onto a ambient light excluding preclinical enclosure. A suitable exposure and processing pipeline were developed with SWIR CLI then performed across a variety of medical radioisotopes at in vitro and in vivo conditions. Results: SWIR CL was detected from the clinical radioisotopes: 90Y, 68Ga, 18F, 89Zr, 131I and 32P, used in biomedical research. SWIR CLIs advantage over conventional CLI is shown in terms with increased light penetration and decreased scattering at depth, in line with fluorescent SWIR imaging. The radioisotope SWIR spectrum is reported, the sensitivity limit (0.23 µCi/µl of 68Ga) and SWIR CLIs preclinical feasibility is shown with ex vivo and in vivo preclinical examples. Conclusion: This work is the first to show that radioisotope SWIR CLI can be performed with commerical components. SWIR CL has significant advanatges over VIS CL and behaves in a similar manner. Further improvements in SWIR optics and technology are required to enable widespread adoption.