RT Journal Article SR Electronic T1 Comparison of data-driven software and external tracking for PET respiratory gating JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 178 OP 178 VO 60 IS supplement 1 A1 Tyler Bradshaw A1 Scott Wollenweber A1 Steve Cho A1 Christine Jaskowiak A1 Robert Jeraj A1 Scott Perlman YR 2019 UL http://jnm.snmjournals.org/content/60/supplement_1/178.abstract AB 178Purpose: Respiratory gating of PET images can improve the conspicuity of small lymph nodes or lesions in the lungs and abdomen, leading to more accurate and confident evaluations. With recent advances in data-driven respiratory gating (DDG), PET respiratory gating can now be performed routinely without the need for equipment setup. DDG methods, however, require clinical validation as they rely on indirect measurements of the respiratory waveforms extracted from list mode data. This study compared a new DDG method to that of a commercial fiducial tracking system in capturing PET respiratory motion. Materials and Methods: Subjects undergoing clinical 18F-FDG PET/CT imaging were prospectively enrolled in the study. Subjects were eligible for the study if prior imaging showed evidence of lesions that might be better evaluated with respiratory gating as determined by a nuclear medicine physician. This included subjects with suspicious lesions in the liver, mid-to-lower lungs, or mediastinum. PET/CT imaging was performed on a GE Discovery PET/CT 710 time-of-flight scanner using the Varian Real-Time Position Management (RPM) external tracking system, with PET acquisition times for bed positions over the lungs and liver extended to 6 minutes instead of the standard clinical 3 minutes. PET list mode data was collected for each subject and GE Healthcare’s DDG software was used to extract respiratory waveforms from the list mode data. The DDG-derived and RPM-derived respiratory waveforms were used to create PET cine loops binned into 6 phases of the respiratory cycle. Two blinded nuclear medicine physicians independently reviewed both of the cine series side-by-side for each subject and recorded if one of the two cine series demonstrated more respiratory motion or were equivalent. When the cine images of one method showed more respiratory motion than the comparator method, this indicated that the first method better captured the underlying respiratory waveform. Physicians also recorded the degree of respiratory motion present in the cine images on a three-point scale (none, mild, or significant). Results: PET scans from 38 subjects were evaluated. Respiratory motion was found to be better captured by DDG in 6/38 cases according to physician 1 and in 9/38 cases according to physician 2. The remaining cases were scored as equivalent between methods. In no case was it found that RPM captured respiratory motion better than DDG. There was strong agreement between physicians in selecting which gating method performed better (kappa=0.76) and in describing the degree of motion present in the images (kappa=0.82). In 4/38 cases, DDG revealed mild respiratory motion where RPM showed none. In 2/38 cases, DDG showed significant motion where RPM showed only mild motion. Conclusions: Data-driven PET respiratory gating performed comparable to, and in many cases better than, external tracking at capturing PET respiratory motion. Therefore, DDG is a reliable and convenient method for respiratory gating of PET images. Research support: This research was supported by GE Healthcare.