Molecular imaging techniques in patients with persistent spinal pain syndrome type 2 - a systematic review and meta-analysis

BACKGROUND: Persistent postoperative low back pain, including persistent spinal pain syndrome type 2 (PSPS-T2), is a global healthcare challenge that lacks objective phenotypic diagnostic criteria or validated biomarkers. Molecular imaging techniques (nuclear medicine) could aid in establishing more objective phenotypical parameters as they are able to visualize biological processes underlying several diseases even before anatomical changes are present. This review aims to provide an overview of the status quo of molecular imaging for the diagnosis of PSPS-T2. METHOD AND RESULTS: An extensive search of PubMed and Embase was conducted to identify relevant studies that comprise imaging techniques using a radiopharmaceutical substance. Evidence reveals that these techniques can provide valuable insights into the underlying pathologies and mechanisms of PSPS-T2 by detecting pain generators that would have otherwise gone unnoticed. Moreover, the meta-analysis showed a pooled sensitivity of 90.3% (95% CI: 53–100%) and a specificity of 89.1% (95% CI: 31–100%) for [18F]NaF PET-CT, and a pooled sensitivity of 61.5% (95% CI: 7–93%) and specificity of 96% (95% CI: 21–100%) for diphosphonates SPECT-CT. CONCLUSION: These findings suggest a potential utility in identifying those who are likely to benefit from surgical re-intervention. This illustrates the potential of molecular imaging in establishing a personalized-medicine approach. However, the retrospective design and the limited sample sizes are among the limitations of the included studies and further research is needed to unravel the potential of molecular imaging techniques as a tool to detect phenotypical biomarkers and to optimize patient care in patients with persistent postoperative low back pain, including PSPS-T2.