Using PET/CT Bone Scan Dynamic Data to Evaluate Tibia Remodeling When a Taylor Spatial Frame Is Used: Short and Longer Term Differences

摘要

Eighteen consecutive patients, treated with a Taylor Spatial Frame for complex tibia conditions, gave their informed consent to undergo Na¹⁸F⁻ PET/CT bone scans. We present a Patlak-like analysis utilizing an approximated blood time-activity curve eliminating the need for blood aliquots. Additionally, standardized uptake values (SUV) derived from dynamic acquisitions were compared to this Patlak-like approach. Spherical volumes of interest (VOIs) were drawn to include broken bone, other (normal) bone, and muscle. The SUVm(t) (m = max, mean) and a series of slopes were computed as (SUVm(t i) − SUVm(t j))/(t i − t j), for pairs of time values t i and t j. A Patlak-like analysis was performed for the same time values by computing ((VOIp(t i)/VOIe(t i))−(VOIp(t j)/VOIe(t _j)))/(t _i − t _j), where p = broken bone, other bone, and muscle and e = expected activity in a VOI. Paired comparisons between Patlak-like and SUV_m slopes showed good agreement by both linear regression and correlation coefficient analysis (r = 84%, r _s = 78%-SUV_max, r = 92%, and r _s = 91%-SUV_mean), suggesting static scans could substitute for dynamic studies. Patlak-like slope differences of 0.1 min⁻¹ or greater between examinations and SUV_max differences of ~5 usually indicated good remodeling progress, while negative Patlak-like slope differences of −0.06 min⁻¹ usually indicated poor remodeling progress in this cohort.