Author of

• 17728

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  P2.04 - Poster Session with Presenters Present (ID 466)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Mesothelioma/Thymic Malignancies/Esophageal Cancer/Other Thoracic Malignancies
  • Presentations: 1
  • Moderators:
  • Coordinates: 12/06/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 17744

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    P2.04-016 - Is FDG-PET Useful for Distinguishing between Thymic Epithelial Tumors and Malignant Lymphoma? (ID 5234)

    14:30 - 14:30  |  Author(s): T. Kinoshita
    • Abstract

    Background:
    It is difficult to diagnose the tumor in the anterior mediastinum by computed tomography. Distinguishing between thymic epithelial tumors and malignant lymphoma is important, because therapeutic strategy is difficult in each disease. The objective of this study was to clarify the usefulness of positron emission tomography (PET) using 18F-fluorodeoxyglucose (FDG) for distinguishing thymic epithelial tumors and malignant lymphoma.
    
    Methods:
    We retrospectively reviewed FDG PET-CT scans of 42 patients pathologically diagnosed by surgery or biopsy as thymic epithelial tumors or malignant lymphoma. FDG uptake was measured as the maximum standard uptake value (SUVmax). Student t tests were used to assess association between SUVmax and pathological diagnosis.
    
    Results:
    Among the 42 patients, 26 patients had a pathological diagnosis of thymoma: WHO classification type A in 3 patients (11%), type AB in 5 patients (19%), type B1 in 10 patients (19%), type B2 in 11 patients (42%), and type B3 in 2 patients (7%). Eight patients had the thymic carcinoma. Eight patients had the malignant lymphoma. The SUVmax in malignant lymphoma (13.4±6.3) was significantly higher than that in the thymic epithelial tumors (4.9±2.4) (p＜0.001). The SUVmax in thymic carcinoma (7.9±3.0) was higher than that in the thymoma (4.5±1.3) (p=0.002) . The ROC curve of SUVmax for predicting malignant lymphoma indicated that the optimal cutoff value　was 7.3. This value had a sensitivity of 0.88 and a specificity of 0.99 (area under curve, 0.93).
    
    Conclusion:
    FDG PET-CT is helpful for distinguishing malignant lymphoma from thymic epithelial tumors with cut off value of 7.3.