Soyeon Park1, Dakeun Lee2, Kee Myung Lee3, Sang-Uk Han4, Jei Hee Lee5, Su Jin Lee1, Young-Sil An1, Joon-Kee Yoon6. 1. Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, Suwon, Republic of Korea. 2. Department of Pathology, Ajou University School of Medicine, Suwon, Republic of Korea. 3. Department of Gastroenterology, Ajou University School of Medicine, Suwon, Republic of Korea. 4. Department of Surgery, Ajou University School of Medicine, Suwon, Republic of Korea. 5. Department of Radiology, Ajou University School of Medicine, Suwon, Republic of Korea. 6. Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, Suwon, Republic of Korea. Electronic address: jkyoon3@ajou.ac.kr.
Abstract
PURPOSE: Lymphoepithelioma-like carcinoma (LELC) is a rare type of gastric cancer. We evaluated the clinical usefulness of F-18 FDG positron emission tomography/computed tomography (PET/CT) in LELC of stomach. MATERIALS AND METHODS: A total of 28 patients (mean age=59years) who underwent preoperative F-18 FDG PET/CT were enrolled retrospectively. Nine patients underwent follow-up F-18 FDG PET/CT. Pathologic information was obtained through gastrectomy and the association with Epstein-Barr virus (EBV) was investigated in 26 patients. RESULTS: PET/CT detected 85.0% (17/20) of advanced gastric cancers (AGC) and 12.5% (1/8) of early gastric cancers (EGC). Most tumors (23/26, 88.5%) were EBV-associated. The maximum standardized uptake value of FDG-avid tumors was 7.5±3.0. The sensitivity and specificity of PET/CT for the presence of lymph node metastasis was 47.8% (11/23) and 100.0% (13/13), respectively. PET/CT also detected a hepatic sarcomatoid carcinoma in one patient. The specificity of PET/CT for distant metastasis or second malignancy was 96.3%. Follow-up PET/CT detected malignant lesions in 3 of 9 patients; a liver metastasis, recurrent hepatic sarcomatoid carcinomas and a metachronous cholangiocarcinoma. PET/CT correctly excluded recurrence in the rest of the patients (6/6). The sensitivity and specificity of PET/CT for detecting recurrence or second malignancy was 100% and 100%, respectively. CONCLUSION: F-18 FDG PET/CT would be a useful tool in evaluating distant metastasis or recurrence in patients with gastric LELC.
PURPOSE:Lymphoepithelioma-like carcinoma (LELC) is a rare type of gastric cancer. We evaluated the clinical usefulness of F-18 FDG positron emission tomography/computed tomography (PET/CT) in LELC of stomach. MATERIALS AND METHODS: A total of 28 patients (mean age=59years) who underwent preoperative F-18 FDG PET/CT were enrolled retrospectively. Nine patients underwent follow-up F-18 FDG PET/CT. Pathologic information was obtained through gastrectomy and the association with Epstein-Barr virus (EBV) was investigated in 26 patients. RESULTS: PET/CT detected 85.0% (17/20) of advanced gastric cancers (AGC) and 12.5% (1/8) of early gastric cancers (EGC). Most tumors (23/26, 88.5%) were EBV-associated. The maximum standardized uptake value of FDG-avid tumors was 7.5±3.0. The sensitivity and specificity of PET/CT for the presence of lymph node metastasis was 47.8% (11/23) and 100.0% (13/13), respectively. PET/CT also detected a hepatic sarcomatoid carcinoma in one patient. The specificity of PET/CT for distant metastasis or second malignancy was 96.3%. Follow-up PET/CT detected malignant lesions in 3 of 9 patients; a liver metastasis, recurrent hepatic sarcomatoid carcinomas and a metachronous cholangiocarcinoma. PET/CT correctly excluded recurrence in the rest of the patients (6/6). The sensitivity and specificity of PET/CT for detecting recurrence or second malignancy was 100% and 100%, respectively. CONCLUSION: F-18 FDG PET/CT would be a useful tool in evaluating distant metastasis or recurrence in patients with gastric LELC.