Role of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of recurrence in patients with cervical cancer

INTRODUCTION: Treatment of cervical cancer is usually surgery in the early stages and radiotherapy or chemoradiotherapy in more advanced stages of the disease. Recurrence may occur in multiple sites following primary treatment. Although recurrent metastatic disease is not curable, surgical treatment may be of great help if locoregional recurrence is detected early. Fluorine-18 Fluorodeoxyglucose positron emission tomography - computed tomography (F-18 FDG PET/CT) forms an important part of investigations in the diagnosis of clinically suspicious recurrent cervical cancer. OBJECTIVE: To assess the role of F-18 FDG PET/CT in diagnosing recurrence in patients with clinical suspicion of recurrent cervical cancer. MATERIALS AND METHODS: We retrospectively evaluated 53 histopathologically proved patients of cervical cancer. All the patients had been treated with either surgery/radiation therapy with or without chemotherapy. The standard PET/CT acquisition protocol, with delayed post void static pelvic images, wherever required, was followed in all patients. Significant uptake of FDG in the lymph nodes was considered to be a recurrence suggestive of metastasis. Para-aortic lymph nodal involvement was considered to be distant metastasis. Any significant uptake in the lung nodule on FDG PET was evaluated either by histological confirmation, by taking fine needle aspiration cytology (FNAC), or by a follow-up chest CT done after three months. RESULTS: Of the 53 patients with clinically equivocal recurrence, FDG PET/CT suggested recurrence in 41 patients (local recurrence in 14 patients and distant recurrence/metastasis with or without local recurrence in 27 patients). It had a sensitivity of 97.5%, a specificity of 63.6%, positive predictive value of 90.9%, and negative predictive value of 87.5%. CONCLUSION: PET/CT appears to have an important role in detecting recurrence following primary treatment of cervical cancer. The high positive and negative predictive values of PET/CT may be helpful in planning management of recurrent cervical cancer.