Diagnostic Value of Dual-Energy CT Iodine Mapping in Differentiating Malignant and Benign Cervical Lymphadenopathies.

Purpose: To evaluate the diagnostic accuracy of Dual-Energy Computed Tomography (DECT) in distinguishing malignant from benign cervical lymph nodes in neck carcinoma based on iodine concentration and normalized spectral attenuation (Hounsfield Unit, HU) values.

Methods: Retrospective DECT scan analysis was performed on 52 neck carcinoma patients, analyzing 52 metastatic and 28 reactive lymph nodes. Iodine concentration (mg/mL) and spectral HU values were measured with circular regions of interest on iodine maps. Metastatic nodes included 27 from squamous cell carcinoma (SCC), 19 from lymphoma, and 6 from papillary thyroid carcinoma (PTC).

Results: Metastatic lymph nodes had lower iodine levels than reactive nodes (1.45 vs. 1.85 mg/mL, p = 0.011). No significant difference in spectral HU values was found (117 vs. 111 HU, p = 0.328). An iodine threshold of 1.62 mg/mL demonstrated 71% sensitivity and 77% specificity for detecting malignancy (AUC = 0.673, 95% CI: 0.54-0.80, p = 0.011). SCC metastases had lower iodine levels than reactive nodes (1.33 vs. 1.85 mg/mL, p < 0.001), while PTC metastases had higher levels (2.39 vs. 1.85 mg/mL, p = 0.038).

Conclusion: DECT iodine quantification improves the detection of cervical lymph node metastases, particularly in cases with equivocal size criteria. Incorporating iodine measurements with tumor type knowledge improves diagnostic accuracy, aiding in prognosis and treatment planning.