Yu Hua Quan1,2, Rong Xu2, Byeong Hyeon Choi1,2, Jiyun Rho1,2, Jun Hee Lee2, Kook Nam Han2, Young Ho Choi2, Beop-Min Kim3, Hyun Koo Kim4,5. 1. Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Republic of Korea. 2. Department of Thoracic and Cardiovascular Surgery, Korea University Guro Hospital College of Medicine, Korea University, Seoul, Republic of Korea. 3. Department of Bio-Convergence, Korea University, Seoul, Republic of Korea. 4. Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Republic of Korea. kimhyunkoo@korea.ac.kr. 5. Department of Thoracic and Cardiovascular Surgery, Korea University Guro Hospital College of Medicine, Korea University, Seoul, Republic of Korea. kimhyunkoo@korea.ac.kr.
Abstract
BACKGROUND: Indocyanine green (ICG) fluorescence imaging has been used to detect many types of tumors during surgery; however, there are few studies on thymic masses and the dose and time of ICG injection have not been optimized. OBJECTIVE: We aimed to evaluate the optimal ICG injection dose and timing for detecting thymic masses during surgery. METHOD: Forty-nine consecutive patients diagnosed with thymic masses on preoperative computed tomography (CT) and scheduled to undergo thymic cystectomy or thymectomy were included. Patients were administered 1, 2, or 5 mg/kg of ICG at different times. Thymic masses were observed during and after surgery using a near-infrared fluorescence imaging system, and the fluorescence signal tumor-to-normal ratio (TNR) was analyzed. RESULTS: Among the 49 patients, 14 patients with thymic cysts showed negative fluorescence signals, 33 patients with thymoma or thymic carcinoma showed positive fluorescence signals, and 2 patients showed insufficient fluorescence signals. The diagnosis of thymic masses based on CT was correct in 32 (65%) of 49 cases; however, the differential diagnosis of thymic masses based on NIR signals was correct in 47 of 49 cases (96%), including 14 cases of thymic cysts (100%) and 33 cases of thymomas or thymic carcinomas (94%). In addition, TNR was not affected by the time or dose of ICG injection, histological type, stage, or tumor size. CONCLUSIONS: Low-dose intravenous injection of ICG at flexible time can detect thymic tumors. In addition, thymic cysts can be distinguished from thymomas or thymic carcinomas during surgery by the absence of ICG fluorescence signals.
BACKGROUND: Indocyanine green (ICG) fluorescence imaging has been used to detect many types of tumors during surgery; however, there are few studies on thymic masses and the dose and time of ICG injection have not been optimized. OBJECTIVE: We aimed to evaluate the optimal ICG injection dose and timing for detecting thymic masses during surgery. METHOD: Forty-nine consecutive patients diagnosed with thymic masses on preoperative computed tomography (CT) and scheduled to undergo thymic cystectomy or thymectomy were included. Patients were administered 1, 2, or 5 mg/kg of ICG at different times. Thymic masses were observed during and after surgery using a near-infrared fluorescence imaging system, and the fluorescence signal tumor-to-normal ratio (TNR) was analyzed. RESULTS: Among the 49 patients, 14 patients with thymic cysts showed negative fluorescence signals, 33 patients with thymoma or thymic carcinoma showed positive fluorescence signals, and 2 patients showed insufficient fluorescence signals. The diagnosis of thymic masses based on CT was correct in 32 (65%) of 49 cases; however, the differential diagnosis of thymic masses based on NIR signals was correct in 47 of 49 cases (96%), including 14 cases of thymic cysts (100%) and 33 cases of thymomas or thymic carcinomas (94%). In addition, TNR was not affected by the time or dose of ICG injection, histological type, stage, or tumor size. CONCLUSIONS: Low-dose intravenous injection of ICG at flexible time can detect thymic tumors. In addition, thymic cysts can be distinguished from thymomas or thymic carcinomas during surgery by the absence of ICG fluorescence signals.
Authors: Jarrod D Predina; Jane Keating; Andrew Newton; Christopher Corbett; Leilei Xia; Michael Shin; Lydia Frenzel Sulyok; Charuhas Deshpande; Leslie Litzky; Shuming Nie; John C Kucharczuk; Sunil Singhal Journal: Cancer Date: 2018-12-18 Impact factor: 6.860