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 Na~(18)F~- 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 SUV_m(t) (m = max, mean) and a series of slopes were computed as (SUV_m(f,) - SUV_m(t_j))/(t_j - t_j), for pairs of time values t_j, and t_j. A Patlak-like analysis was performed for the same time values by computing ((VOI_p(t_i)/VOI_e(t_i)) -(VOI_p(t_j)/VOI_e(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 SUVm 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.