The current OHSU Single Photon Emission Computed Tomography (SPECT) protocol for 177Lu radiopharmaceutical dosimetry takes roughly 1 hour, which is difficult for both patients and scheduling. Reducing frame duration would reduce scan time, however the effect on dosimetry results is unknown. In this research, we investigated the validity of a retrospective frame shortening reconstruction technique using phantom scans, with the eventual goal of shortening patient scans.