The Role of 18F-Flourodeoxyglucose (18F-FDG) Positron Emission Tomography/Computed Tomography (PET/CT) in Pelvic and Paraaortic Lymph Node Staging of Uterine Cervical Cancer

Abstract

Aim: We aimed to evaluate the sensitivity of 18F-Flourodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in the detection of pelvic and paraaortic lymph node metastases of uterine cervical cancer.
 Material and Method: 32 female patients (mean age: 56.1±12.6) who underwent 18F-FDG PET/CT for preoperative staging of uterine cervical cancer between April 2009 and October 2013 were included to the study. Ethical committee approval was taken from Ankara University Medical Faculty Ethics Committee. All the patients had been performed trans-vaginal examination and diagnosed as uterine cervical cancer before 18F-FDG PET/CT. 18F-FDG PET/CT findings were compared with histopathological examination results. Sensitivity, specificity and accuracy of pelvic MRI and 18F-FDG PET/CT were calculated in the detection of pelvic and paraaortic lymph node metastases.
 Results: 18F-FDG uptake was seen in primary cervical lesions of all the patients. Mean SUV max of primary cervical lesions was calculated as 13.6±6.6 (range: 6.7-25). In 16 (50%) patients, 18F-FDG uptake was not seen in pelvic and paraaortic lymph nodes. In the remaining patients, 18F-FDG uptake was detected in pelvic nodes in all the patients (50%) and in paraaortic nodes in 6 (18%) patients. Mean SUV max of pelvic lymph nodes were calculated as 8.4±5.2 and of paraaortic lymph nodes 12.45±6.41. 18F-FDG uptake was detected in a total of 47 lymph node stations in 16 patients. Mean SUVmax of all lymph nodes were calculated as 8.9±5.83 (range: 2.6-21.9). According to 18F-FDG PET/CT findings, disease was upstaged from I to IV in 1 (3%) patient, II to III in 2 (6%) patients, III to IV in 1 (3%) patients and I to III in 2 (6%) patients, and down staged from III to I in 1 (3%) patient, respectively. In the patient-based analysis, 18F-FDG PET/CT was TP, TN, FP and FN in 14 (%44), 14 (44%), 2 (6%) and 2 (6%) patients, respectively. Patients based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 87%, 87% and 87%, respectively. In the lesion-based analysis, 18F-FDG PET/CT was TP, FP, TN and FN in 30, 7, 37 and 5 lymph node stations, respectively. Lesion based sensitivity; specificity and accuracy of 18F-FDG PET/CT were calculated as 85%, 84% and 84%, respectively.
 Conclusion: 18F-FDG PET/CT is a reliable imaging tool with its high sensitivity and specificity in the pelvic and paraaortic lymph node staging of uterine cervical cancer. When performed in the preoperative staging it changes disease stage about in ¼ of patients. In combination of pelvic MRI, primary staging of primary cervical lesions and also pelvic/paraaortic lymph nodes can be done successfully.