Diagnosis of Recurrent Uterine Cervical Cancer: Computed Tomography versus Positron Emission Tomography Dong Hee Park, MD1 Kie Hwan Kim, MD1 Sang Yoon Park, MD2 Byung Hee Lee, MD1 Chang Woon Choi, MD3 Soo Yil Chin, MD1 Index words: Uterine neoplasms, CT Uterine neoplasms, radionuclide studies Positron emission tomography (PET), comparative studies Korean J Radiol 2000;1 :51-55 Received October 13, 1999; accepted after revision January 6, 2000. Departments of 1Diagnostic Radiology, 2Obstetrics and Gynecology, and 3Nuclear Medicine, Korea Cancer Center Hospital. Address reprint requests to: Dong Hee Park, MD, Department of Diagnostic Radiology, Korea Cancer Center Hospital, 215-4, Gongneung-Dong, Nowon-Gu, Seoul 139-240, Korea. Telephone: (822) 974-2501 Fax: (822) 972-3093 Objective: To determine the accuracy of CT and positron emission tomogra- phy (PET) in the diagnosis of recurrent uterine cervical cancer. Materials and Methods: Imaging findings of CT and PET in 36 patients (mean age, 53 years) in whom recurrent uterine cervical cancer was suspected were analyzed retrospectively. Between October 1997 and May 1998, they had under- gone surgery and/or radiation therapy. Tumor recurrence was confirmed by pathologic examination or follow-up studies. Results: In detecting recurrent uterine cervical cancer, the sensitivity, specifici- ty, and accuracy of CT were 77.8%, 83.3%, and 80.5%, respectively, while for PET, the corresponding figures were 100%, 94.4%, and 97.2%. The Chi-square test revealed no significant difference in specificity (p = .2888), but significant dif- ferences in sensitivity (p = .0339) and accuracy (p = .0244). Conclusion: PET proved to be a reliable screening method for detecting recur- rent uterine cervical cancer, but to determine the anatomical localization of recur- rent tumors, and thus decide an adequate treatment plan, CT was eventually needed. T he recurrence rate of uterine cervical cancer is reported to be 6.5% after surgery and 26.2% after radiation therapy alone (1). Radiological studies such as intravenous urography (IVU), US, CT, and MR imaging are used to detect recurrent cervical cancer (2). It is difficult, however, for these imaging modali- ties to differentiate recurrent tumor from postoperative or radiation fibrosis, and to de- tect metastatic normal-sized lymph nodes and extrapelvic metastases (2 7). Since Di Chiro et al. (8) first used it to detect recurrent brain tumors, positron emis- sion tomography (PET), the diagnostic modality which makes use of increased glycoly- sis in tumor cells, has been used to detect recurrent tumors in many organs. To our knowledge, no report has described the diagnosis of recurrent cervical cancer using PET. The purpose of this study is to compare the accuracy of CT with that of PET in the detection of recurrent cervical cancer. MATERIALS AND METHODS Among patients with uterine cervical cancer who had undergone initial treatment between October 1997 and May 1998, CT and PET were performed in 36 in whom recurrence was clinically suspected. As initial treatment, 13 patients had undergone surgery alone, 14 radiation therapy alone, and nine surgery and postoperative radia- tion therapy. Recurrence was suspected on the basis of increased levels of serum squa- Korean J Radiol 1(1), March 2000 51