Nimg-88. thallium 201 single photon emission ct (ti-spect) for differentiation of malignant versus benign nervous system space occupying lesions: a retrospective study, systematic review, and meta-analysis

Abstract Importance Thallium-201 single-photon emission computed tomography (TI-SPECT) imaging has been used historically to distinguish malignant cerebral neoplasms from infectious etiologies. Objectives Our study aims to review existing literature and conduct a retrospective study and meta-analysis on the use of TI-SPECT to differentiate malignant from non-malignant nervous system lesions. Data Sources A retrospective study on use of TI-SPECT in differentiating malignant versus benign nervous system masses was conducted in two tertiary hospitals in the Philippines. Systematic review of relevant studies regarding TI-SPECT for brain and spinal cord lesions was also done. Meta-analysis was performed to generate pooled sensitivity and specificity. Study Selection All study types published in the English language were included – randomized controlled trials (RCTs), prospective/retrospective cohort studies, and case series and reports; abstract only studies were excluded. Studies that involved either pediatric and adult cases were considered. Data Extraction and Synthesis The study complied with the Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) Guidelines. Main Outcome and Measure The primary outcome was sensitivity and specificity of TI-SPECT. This involved getting correlation of positive and negative thallium scan uptake with either biopsy results (if available) or diagnosis via clinical response to treatment (i.e. whether cases that were managed as infection or demyelination showed improvement on follow-up). RESULTS: Thirty-two (32) articles were qualitatively described and 25 datasets were subjected to meta-analysis. Pooled sensitivity and specificity were 0.89 (95% CI: 0.82-0.94) and 0.82 (95% CI: 0.74-0.88), respectively with an area under the curve (AUC) for diagnostic accuracy of 0.92. CONCLUSION: and Relevance Thallium scans may be utilized to discriminate malignant from benign nervous system lesions, especially, in cases with a >80% pre-test probability. Further studies are needed to validate this findings.