Monte Carlo simulation of the acquisition conditions for 177Lu molecular imaging of hepatic tumors

To examine the impact of acquisition time on Lutetium-177 (177Lu) single-photon emission computed tomography (SPECT) images using Monte Carlo simulation. A gamma camera simulation based method was performed to produce SPECT images. The phantom modeled a NEMA IEC BODY including six spheres as tumors. After administration 7.4 GBq 177Lu, radioactivity concentrations tumor/liver at 6, 24, and 72 h after were set 1.85/0.201, 2.12/0.156, 1.95/0.117 MBq/mL, respectively. In addition, tumor varied by 1/2, 1/4, 1/8 when comparison made. Acquisition times examined 1.2, 1.5, 2, 3, 12 min. assess collimators, data acquired collimators low-energy high-resolution (LEHR), extended general-purpose (ELEGP), medium-energy, (MEGP-1, MEGP-2, MEGP-3) high-energy (HEGP) examined. prefiltering Butterworth filter, projection reconstructed ordered subset expectation maximization. detected photons classified into direct rays, scattered penetrating characteristic X-rays from lead. image quality evaluated through visual assessment, physical assessment contrast recovery coefficient (CRC) contrast-to-noise ratio (CNR). this study, CNR threshold for detectability assumed be 5.0. compare highest sensitivity observed with ELEGP, followed LEHR MEGP-1. ray also in ELEGP concentration ratios tumor/liver, CRC significantly decreased smaller ratios. This effect greater larger spheres. According 3 min or longer required collimator administration, Physical suggested that necessary administration. 177Lu-SPECT generated via recommended 6 24