Impact of 18F-FDG PET on TNM Staging and Prognosis in Thymic Epithelial Tumors

• Published in: Annals of surgical oncology 2024, Vol.31 (1), p.192-200
• Main Authors: Akamine, Takaki, Nakagawa, Kazuo, Ito, Kimiteru, Watanabe, Hirokazu, Yotsukura, Masaya, Yoshida, Yukihiro, Yatabe, Yasushi, Kusumoto, Masahiko, Watanabe, Shun-ichi
• Format: Article
• Language: English
• Subjects: Lymph nodes; Medical prognosis; Medicine; Medicine & Public Health; Metastases; Metastasis; Oncology; Positron emission tomography; Prognosis; Surgery; Surgical Oncology; Thoracic Oncology; Thorax; Thymus; Tumors
• ISSN: 1068-9265; 1534-4681
• DOI: 10.1245/s10434-023-14328-z

Background Preoperative fluorine-18-fluorodeoxyglucose positron emission tomography ( 18 F-FDG PET) of thymic epithelial tumors (TETs) is well known for identifying malignant-grade TETs; however, its predictive power for determining locally advanced tumors, lymph node (LN) metastasis, and prognosis remains unknown. Patients and Methods We retrospectively evaluated patients with resectable TETs who were preoperatively assessed using 18 F-FDG PET from January 2012 to January 2023. The receiver operating characteristic curve was used to evaluate the cutoff value of the maximum standardized uptake value (SUVmax) to predict advanced-stage disease. Recurrence/progression-free survival (RFS/PFS) was analyzed using the Kaplan–Meier method. The staging was classified according to the tumor–node–metastasis system. Results Our study included 177 patients; 145 (81.9%) had pathological early-stage TET (stage I or II), and 32 (19.1%) had advanced stage (stage III or IV). The area under the curve value for predicting the advanced stage was 0.903, and the cutoff value was 5.6 (sensitivity 81.3%, specificity 84.8%). SUVmax > 5.6 was associated with worse prognosis for RFS/PFS. LN metastasis was preoperatively detected by FDG uptake in 30.8% of patients with pathological LN positivity, whereas LN metastasis was not pathologically detected in patients with SUVmax