Assessment of successful incorporation of cages after cervical or lumbar intercorporal fusion with [(18)F]fluoride positron-emission tomography/computed tomography

摘要

The purpose of this study is to assess the successful incorporation of cages in patients after cervical or lumbar intercorporal fusion with positron-emission tomography/computed tomography (PET/CT). Twenty patients (14 female and 6 male; mean age 58?years, age range 38–73?years) with 30 cervical (n?=?13) or lumbar (n?=?17) intercorporal fusions were prospectively enrolled in this study. Time interval between last intercorporal intervention and PET/CT ranged from 2 to 116?months (mean 63; median 77?months). IRB approval was obtained for all patients, and written informed consent was obtained from all patients. About 30?min prior to PET/CT scanning, 97–217?MBq (mean 161?MBq) 18F-fluoride were administered intravenously. Patients were imaged in supine position on a combined PET/CT system (Discovery RX/STE, 16/64 slice CT, GE Healthcare). 3D-PET emission data were acquired for 1.5 and 2?min/bed position, respectively, and reconstructed by a fully 3D iterative algorithm (VUE Point HD) using low-dose CT data for attenuation correction. A dedicated diagnostic thin-slice CT was optionally acquired covering the fused region. Areas of increased 18F-fluoride uptake around cages were determined by one double-board certified radiologistuclear physician and one board certified radiologist in consensus. In 12/20 (60%) patients, increased 18F-fluoride uptake around cages was observed. Of the 30 intercorporal fusions, 15 (50%) showed increased 18F-fluoride uptake. Median time between intervention and PET/CT examination in cages with increased uptake was 37?months (2–116?months), median time between intervention and PET/CT examination in those cages without increased uptake was 91?months (19–112?months), p (Wilcoxon)?=?0.01 (one-sided). 14/29 (48%) cages with a time interval??1?year between intervention and PET/CT scan showed an increased uptake. In conclusion, PET/CT frequently shows increased 18F-fluoride uptake in cervical and lumbar cages older than 1?year (up to almost 8?years in cervical cages and 10?years in lumbar cages) possibly indicating unsuccessful fusion due to increased stress/microinstability...