Recurrent Uterine Cervical Cancer: CT versus PET was only one false positive. On CT, sensitivity, specificity, and accuracy were 77.8%, 83.3%, and 80.5%, respective- ly, while for PET, the corresponding figures were 100%, 94.4%, and 97.2% (Table 1). The three false-positive cases interpreted as recurrence of soft tissue masses in the pelvic cavity and seen on CT showed no high metabolic area on PET, and were shown by follow-up study to be postoperative or radiation fibrosis (Fig. 1). The four false-negative cases seen on CT and inter- preted as no recurrence were lymph nodes smaller than 1 cm in the abdomen, pelvic cavity, and inguinal area (Fig. 2). Unfortunately, however, they showed a high metabolic area and were confirmed by follow-up percutaneous biop- sy or increased size as recurrence. The one false-positive case thought because of the high metabolic area seen on PET in the left upper lung field to be recurrence, was shown by follow-up study and sputum polymerase chain reaction to be tuberculosis (Fig. 3). Due to poor spatial resolution, PET failed to detect the extent of recurrent pelvic masses and the exact level of lymph nodes. To determine the possibilities of surgery and the required extent of radiation therapy, CT was therefore A B Fig. 2. A 52-year-old woman who had undergone radiation therapy due to uterine cervical cancer. A. Enhanced CT scan shows lymph node smaller than 1cm in the para-aortic area (arrow). B. PET scan shows hypermetabolic area (SUV = 3.8 ml/kg) in the para-aortic chain (arrow). A B Fig. 3. A 41-year-old woman with uterine cervical cancer. False positive PET scan due to pulmonary tuberculosis. A. CT scan shows multiple nodules in left upper lung (arrows). B. PET scan shows hypermetabolic lesion (SUV = 9.6 ml/kg) in left upper lung (arrow). Tuberculosis was confirmed by polymerase chain reaction of the sputum. Korean J Radiol 1(1), March 2000 53