Practical methods to differentiate thymic malignancies by positron-emission tomography and tumor markers

Area of Science:

• Oncology
• Nuclear Medicine
• Diagnostic Imaging

Background:

• Thymic malignancies pose diagnostic challenges due to varied differential diagnoses.
• Accurate diagnosis is crucial for effective treatment planning in anterior mediastinal tumors.

Purpose of the Study:

• To evaluate the diagnostic efficacy of Positron Emission Tomography/Computed Tomography (PET/CT) and tumor markers for thymic malignancies.
• To differentiate between thymic carcinoma, thymoma, lymphoma, and other anterior mediastinal tumors.

Main Methods:

• Retrospective analysis of 139 patients with primary anterior mediastinal tumors (January 2012 - December 2021).
• Evaluation of maximum standardized uptake value (SUVmax) from PET/CT and serum tumor markers, including cytokeratin 19 fragment (CYFRA 21-1).
• Correlation of imaging and biomarker data with pathological diagnoses using Receiver Operating Characteristic (ROC) curve analysis.

Main Results:

• SUVmax was significantly higher in lymphoma, followed by thymic carcinoma, then thymoma.
• CYFRA 21-1 levels were significantly elevated in thymic carcinoma compared to other groups.
• A combination of SUVmax (cut-off 8) and CYFRA 21-1 (cut-off 3) achieved 91.4% accuracy in diagnosing thymic carcinoma.

Conclusions:

• SUVmax and CYFRA 21-1 are significant indicators for diagnosing thymic carcinoma.
• Combining PET/CT SUVmax and CYFRA 21-1 improves diagnostic accuracy for thymic malignancies.
• Enhanced diagnostic accuracy facilitates optimal treatment strategy selection for thymic malignancies.