Diagnostic Efficacy of ¹³¹I-SPECT/CT in Detecting Postoperative Residual and Recurrent Lesions in Patients With Differentiated Thyroid Cancer: A Meta-Analysis

Single-photon emission computed tomography/computed tomography (SPECT/CT) technology is a promising imaging tool for the detection of postoperative residual and recurrent lesions in differentiated thyroid cancer (DTC). However, existing studies presented mixed results, and the overall diagnostic efficacy of this technology remains unclear. Therefore, this meta-analysis was conducted to systematically evaluate the diagnostic value of ¹³¹I-SPECT/CT for identifying residual or recurrent disease in patients with DTC.

A systematic literature search was conducted across PubMed, Web of Science, EMBASE, and Cochrane Library from inception to 4 December 2025. The search strategy incorporated relevant keywords and MeSH terms, such as "differentiated thyroid cancer", "thyroidectomy", "SPECT", "SPECT/CT", "SPECT-CT", "metastasis", "recurrence", and "residual". Study selection, data extraction, and risk-of-bias assessment were performed independently by two investigators. The overall diagnostic performance was assessed by calculating the pooled sensitivity (SENS), specificity (SPEC), and summary receiver operating characteristic (SROC) curve. Sensitivity analyses were performed by excluding individual studies to assess the robustness and stability of the pooled results. Subgroup analysis was used to determine the source of heterogeneity.

Six studies involving 800 patients were included. Pooled analysis showed that lesion-level ¹³¹I-SPECT/CT had a pooled SENS of 0.59 (0.33-0.81) and a pooled SPEC of 0.92 (0.85-0.96). The pooled diagnostic odds ratio (DOR) was 18 (3-91), and the area under the curve (AUC) was 0.92. Based on patient-level ¹³¹I-SPECT/CT, the pooled SENS was 0.89 (0.63-0.98), the pooled SPEC was 0.95 (0.70-0.99), and the DOR was 166 (7-4126). The AUC of the SROC curve was 0.97. The overall diagnostic accuracy of ¹³¹I-SPECT/CT was confirmed, regardless of whether it was conducted at the patient or lesion level. To avoid potential patient overlap, we excluded an earlier study for a sensitivity analysis. The results after exclusion remained within reasonable limits, supporting the robustness of the main findings. Subgroup analyses indicated that patient type may be a potential source of heterogeneity in the non-threshold effect. No publication bias was statistically suggested through Deeks' funnel plot.

¹³¹I-SPECT/CT demonstrates efficacy for the targeted detection of postoperative residual and recurrent lesions in DTC, showing high diagnostic accuracy. However, existing evidence is subject to high heterogeneity, and clinical application should be carefully interpreted in combination with the specific characteristics of patients. Future higher-quality studies conducted using unified standards are needed to further verify its clinical value.