Clinical outcomes after SPECT/CT-guided dual medial branch block and radiofrequency ablation for cervical and thoracic facet pain.

BACKGROUND

Radiofrequency ablation (RFA) is an established treatment for cervical and thoracic facet-mediated pain, but selecting the most appropriate treatment levels remains challenging. Single-photon emission computed tomography/computed tomography (SPECT/CT) has been proposed as an adjunct imaging modality to identify metabolically active facet joints, though its relationship to clinical outcomes is not well defined.

OBJECTIVE

To describe outcomes following SPECT/CT-guided dual MBB and RFA and to explore whether concordance between SPECT/CT findings and RFA target levels was associated with differences in pain and disability.

METHODS

This retrospective single-center cohort included patients who underwent SPECT/CT imaging, dual diagnostic medial branch blocks, and subsequent RFA between January 2023 and May 2025. SPECT/CT imaging was ordered at the discretion of the treating physician, and the resulting cohort reflects patients selected for imaging as part of routine clinical care. Pain was assessed using the Numeric Rating Scale (NRS) and disability using the Modified Oswestry Disability Index (MODI). Minimum clinically important difference (MCID) was defined as a ≥34% reduction in NRS and a ≥17% reduction in MODI. An exploratory Fisher's Exact Test with exact odds ratios (OR) and 95% confidence intervals (CI) was used to compare MCID achievement between combined cohorts.

RESULTS

Twenty-two patients met inclusion criteria (cervical n = 16; thoracic n = 6). Subgroups were Concordant (n = 6), Partially Concordant (n = 6), Discordant (n = 3), and No Facet Uptake (n = 7). At first follow-up, 16/18 patients (89%) achieved MCID for NRS and 7/13 (54%) achieved MCID for MODI. The small sample size limited the ability to detect differences between concordance groups (NRS 80% vs 100%, p = 0.48; OR 0.00, 95% CI 0.00-6.62; MODI 62.5% vs 40%, p = 0.59; OR 2.32, 95% CI 0.16-44.94); these results are reported for descriptive purposes.

CONCLUSIONS

Clinically meaningful pain reduction following RFA was observed across all concordance categories. The study was not adequately powered to detect an association between SPECT/CT-RFA concordance and clinical outcomes. Observed point estimates and wide confidence intervals are reported for descriptive purposes. These preliminary findings suggest that SPECT/CT may serve as a complementary diagnostic tool within current interventional pain practice. Larger prospective studies with a non-SPECT/CT control arm are needed to further define its role in procedural planning and patient selection.