부산대학교 도서관

Cherenkov luminescence imaging modality takes advantage of optical Cherenkov photons since this light could be used for photoactivation, photodynamic therapy, photothermal therapy, excited fluorophores, etc. The aim of this work is to experimentally determine 18F Cherenkov spectrum from 200 to 1050 nm. By Monte Carlo simulation in a mouse modeled, the number of absorbed photons and those ballistic and scattered that left the mouse were computed to determine its implications on optical dosimetry. An 18F-FDG source was used to measure the Cherenkov emission of 18F by placing it inside the 6" integrating sphere. Light was measured 100 times for two different activities with a Cherenkov spectrophotometer and all spectra with similar form and central moment were selected. In this group, the average Cherenkov spectrum was generated from 200 to 1050 nm, then the amount of Cherenkov photons emitted in the 200–1050-nm range was computed. The mouse body was set up in the MCLTmx code using an ellipsoidal figure, with dimensions and mass corresponding to the average size of a 10-to-12-weeks-old male mouse that is the optimal age for experimentation. A Cherenkov light (CL) isotropic point-source was also simulated; it was placed at the origin of the ellipsoid, moving on the y-axis from 0 to 1.2 cm in 0.2 cm increments. As a result, the Cherenkov spectra absorbed and leaving the ellipsoid were obtained. The average experimental Cherenkov spectrum of 18F for 200–1050 nm was obtained. 18F emits 3.28 photons per decay in 200–1050 nm range if the beta is emitted in a medium with a 1.33 refractive index, that corresponds to water. The number of photons per decay emerging from the ventral and dorsal sides of the murine model was computed by Monte Carlo Simulation. Preclinical dosimetry will be more accurately ascertained as the relation between activity in a target region and the amount of CL leaving a volume such as that of a mouse. On the other hand, adequate internal dosimetry will help to predict with greater certainty whether the energy deposited in a volume of interest will be able to induce therapeutic effects. [ABSTRACT FROM AUTHOR]