Efficacy and safety of [18F]NaF PET/CT guided intraarticular block for lumbar facet joint and sacroiliac joint arthropathy: a single-arm phase 2 trial.

Abstract

PURPOSE To evaluate the efficacy and safety of robotic-arm-assisted [18F]NaF-PET/CT-guided intra-articular block for lumbar facet joint (LFJ) or sacroiliac joint (SIJ) arthropathy. MATERIALS AND METHODS In this single-centre, non-randomized, prospective phase 2 clinical-trial, participants with chronic low back pain (CLBP) were recruited from August 2022 to June 2024. Participants having NaF-avid LFJ or SIJ on [18F]NaF-PET/CT underwent robotic-arm-assisted intra-articular block with steroids and local anaesthesia. Baseline, immediate post-procedural, and 3-month follow-up visual analog score (VAS), Low-Back Outcome Scale (LBOS), Oswestry Disability Index (ODI), and change in SUV values of target joints were documented. The primary end-point of the trial was ≥ 50% improvement in VAS at 3 months, and secondary end-points were improvements in ODI, LBOS by at least one grade and change in SUV. Descriptive statistics were applied. Qualitative variables were reported in percentages. RESULTS Out of 85 enrolled participants, 79 (92.9%) underwent [18F]NaF-PET/CT. Among them, 61 (77.2%) had NaF-avid joints, and 55(69.6%) underwent PET/CT-guided robotic-arm-assisted intra-articular blocks. The primary end-point was met in 84% (46/55) participants, and secondary end-points in 96% (53/55) and 89% (49/55), respectively. The procedure was technically successful in all the target joints. A significant change in pre- and post-procedural median SUVmax and SUVpeak of the treated joints was noticed. No major adverse effects were noticed in the participants. CONCLUSION Robotic-arm-assisted [18F]NaF-PET/CT guided intra-articular blocks of LFJ and SIJ in CLBP appear to be safe and feasible in NaF-avid arthropathy. However, lack of comparison with the standard of care, small sample size, selection bias and radiation exposure limit its generalizability.