The 18F-fluorodeoxyglucose positron emission tomograhy in predicting residual retro-peritoneal tumor after chemotherapy of testis germ cell tumors / 中国肿瘤临床

ABSTRACT

Objective:To determine the value of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) scans in identify-ing the residual retroperitoneal tumor after chemotherapy of testis germ cell tumors. Methods:Sixteen testis germ cell tumor patients with metastasis of retroperitoneal lymph nodes who were treated in our hospital from February 2014 to December 2016 were select-ed for the study from February 2014 to December 2016. After 4-6 cycles of chemotherapy, their CT scans showed residual masses with diameters greater than 2 cm. The retroperitoneal lymph nodes were dissected after the 18F-FDG PET exam. The post-surgery pathology results were compared with the results of the 18F-FDG PET exam. Results:Residual tumors were found in 5 of 10 patients with 18F-FDG PET positive. Residual tumor was absent in 4 of 6 patients with 18F-FDG PET negative, while residual mature teratoma tumors were found in two patients. The accuracy rate, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 18F-FDG PET exam were 56.25%(9/16), 71.42%(5/7), 44.44%(4/9), 50.00%(5/10), and 66.67%(4/6), respectively. Conclusion: 18F-FDG PET is highly sensitive. However, many factors influence the result of 18F-FDG PET. Mature teratoma leads to a false negative re-sult, whereas massive tissue inflammation leads to a false positive result. Therefore, more clinical examinations should be made.