울산의대 / 한상원, 김용일*
Abstract
Objectives: We aimed to evaluate the diagnostic ability for the prediction of histologic grades and prognostic values on recurrence and death of pretreatment 2-[18F]FDG PET/CT in patients with resectable thymic epithelial tumours (TETs).
Methods: One hundred and fourteen patients with TETs who underwent pretreatment 2-[18F]FDG PET/CT between 2012 and 2018 were retrospectively evaluated. TETs were classified into three histologic subtypes: low-risk thymoma (LRT, WHO classification A/AB/B1), high-risk thymoma (HRT, B2/B3), and thymic carcinoma (TC). Area under the receiver operating characteristics curve (AUC) was used to assess the diagnostic performance of PET/CT variables (maximum standardised uptake value [SUVmax], metabolic tumour volume [MTV], total lesion glycolysis [TLG], maximum diameter). Cox proportional hazards models were built using PET/CT and clinical variables.
Results: The tumours included 52 LRT, 33 HRT, and 29 TC. SUVmax showed good diagnostic ability for differentiating HRT/TC from LRT (AUC 0.84, 95% confidence interval [CI] 0.76 - 0.92) and excellent ability for differentiating TC from LRT/HRT (AUC 0.94, 95% CI 0.90 - 0.98), with significantly higher values than MTV, TLG, and maximum diameter. With an optimal cut-off value of 6.4, the sensitivity, specificity, and accuracy for differentiating TC from LRT/HRT were 69%, 96%, and 89%, respectively. In the multivariable Cox proportional hazards analyses for freedom-from-recurrence, SUVmax was an independent prognostic factor (p < 0.001), whereas MTV and TLG were not. SUVmax was a significant predictor for overall survival in conjunction with clinical stage and resection margin.
Conclusion: SUVmax showed excellent diagnostic performance for prediction of TC and significant prognostic value in terms of recurrence and survival.
Key points: • Maximum standardised uptake value (SUVmax) shows excellent performance in the differentiation of thymic carcinoma from low- and high-risk thymoma. • SUVmax is an independent prognostic factor for freedom-from-recurrence in the multivariable Cox proportional hazard model and a significant predictor for overall survival. • 2-[18F]FDG PET/CT can provide a useful diagnostic and prognostic imaging biomarker in conjunction with histologic classification and stage and help choose appropriate management for thymic epithelial tumours.
Affiliations
Sangwon Han 1 , Yong-Il Kim 2 , Jungsu S Oh 1 , Seung Yeon Seo 1 , Min-Jae Park 3 , Geun Dong Lee 4 , Sehoon Choi 4 , Hyeong Ryul Kim 4 , Yong-Hee Kim 4 , Dong Kwan Kim 4 , Seung-Il Park 4 , Jin-Sook Ryu 1
1 Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Korea.
2 Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Korea. kyi821209@naver.com.
3 Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
4 Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
편집위원
18F-FDG PET CT로 thymic epithelial tumor의 재발과 사망을 예측할 수 있는지를확인한 임상연구임. 해당 연구 결과에 따른면 MTV나 TLG는 생존률에 독립적인 예후인자가 되지 못하였으나, SUVmax는 생존률에 대한 독립적 예후인자임을 확인하 연구임. 흉선암 관련 임상가 및 종양 핵의학 연구자에게 관심을 끌 연구로 생각됨.
2022-03-18 11:04:50