PET/CT scan improves detection of metastatic disease compared with CT scan alone in women with high-grade neuroendocrine cervical cancer: a NeCTuR study

Objective To determine the optimal imaging modality for women with high-grade neuroendocrine carcinoma of the cervix. Methods Women with high-grade neuroendocrine carcinoma of the cervix who had undergone a computed tomography (CT) scan and combined positron emission tomography with computed tomography (PET/CT) scan within 4 weeks of each other were identified from the NeCTuR Cervical Tumor Registry. One radiologist reviewed all CT scans, and another radiologist reviewed all PET/CT scans. The radiologists denoted the presence or absence of disease at multiple sites. Each radiologist was blinded to prior reports, patient outcomes, and the readings of the other radiologist. With findings on PET/CT used as the gold standard, sensitivity, specificity, and accuracy were calculated for CT scans. Results Fifty matched CT and PET/CT scans were performed in 41 patients. For detecting primary disease in the cervix, CT scan had a sensitivity of 85%, a specificity of 46%, and an accuracy of 74%. For detecting disease spread to the liver, CT scan had a sensitivity of 80%, a specificity of 89%, and an accuracy of 86%. For detecting disease spread to the lung, CT had a sensitivity of 89%, a specificity of 68%, and an accuracy of 77%. Of the 14 patients who had scans for primary disease work-up, 4 (29%) had a change in their treatment plan due to the PET/CT scan. Had treatment been prescribed on the basis of the CT scan alone, 2 patients would have been undertreated, and 2 would have been overtreated. Conclusion A CT scan is inferior to a PET/CT scan in assessment of metastatic disease in women with high-grade neuroendocrine carcinoma of the cervix. Almost one-third of patients with newly diagnosed high-grade neuroendocrine cervical cancer would have received incorrect therapy had treatment planning been based solely on a CT scan. We recommend a PET/CT scan for both initial work-up and surveillance in women with high-grade neuroendocrine carcinoma of the cervix.