Which imaging modality is more accurate than CT for detecting cancer spread to mediastinal lymph nodes?

Which imaging modality is more accurate than CT for detecting cancer spread to mediastinal lymph nodes?

• A. PET-CT
• B. CT
• C. MRI
• D. Ultrasound

Answer: (A)

Metabolic imaging with PET-CT is more accurate than CT for assessing cancer spread to mediastinal lymph nodes. PET detects increased glucose uptake typical of malignant cells, revealing metastases that may not cause node enlargement. When combined with CT, you get precise anatomical localization of these metabolically active nodes, improving both sensitivity and specificity for nodal involvement. This global metabolic view also helps distinguish malignant nodes from benign inflammatory ones to some extent, aiding staging and treatment planning. In contrast, CT relies on size criteria and can miss micrometastases or falsely label enlarged inflammatory nodes as positive, and MRI or ultrasound don’t offer the same whole-mediastinum functional assessment for nodal metastasis.

Metabolic imaging with PET-CT is more accurate than CT for assessing cancer spread to mediastinal lymph nodes. PET detects increased glucose uptake typical of malignant cells, revealing metastases that may not cause node enlargement. When combined with CT, you get precise anatomical localization of these metabolically active nodes, improving both sensitivity and specificity for nodal involvement. This global metabolic view also helps distinguish malignant nodes from benign inflammatory ones to some extent, aiding staging and treatment planning. In contrast, CT relies on size criteria and can miss micrometastases or falsely label enlarged inflammatory nodes as positive, and MRI or ultrasound don’t offer the same whole-mediastinum functional assessment for nodal metastasis.