Park et al. mous cell carcinoma antigen (SCCA) and carcinoembryon- ic antigen (CEA), pain in the lower abdomen and back, edema of the lower leg, and oliguria. All patients underwent CT and PET, the former involv- ing the use of a GE CT/i 9800 scanner (General Electric Medical Systems, Milwaukee, WI), with 10mm thickness. Images of the chest, abdomen, and pelvis were obtained af- ter intravenous injection of 150 ml non-ionic contrast me- dia. For PET, 18F-FDG (2-[fluorine-18]fluoro-2-deoxy-D- glucose) with a GE Advance scanner (General Electric Medical Systems, Milwaukee, WI) was used. During the six hours prior to scanning, patients were restricted to orally and intravenously administered glucose. In the PET room, 10mCi of FDG was administered intravenously prior to in- travenous hydration with one liter of normal saline. Thirty minutes after the administration of FDG, Lasix 20 mg was intravenously injected. To avoid artifactual accumulation of FDG in the urinary bladder, a Foley catheter with drai- nage bag was then positioned. Two radiologists (DHP, KHK) and one nuclear medicine physician (CWC) retrospectively analyzed the imaging find- ings. As seen on CT, definite metastatic mass or a nodule and lymph node larger than 1 cm along the short axis were interpreted as positive findings. On PET, we interpreted a high metabolic area of over 2.5 ml/kg of SUV (standardized uptake value; mean activity of region of interest [mCi/ ml]/injected dose [mCi/ ml]/body weight[kg]) as a positive finding. Recurrence was confirmed by percutaneous lymph node biopsy in ten patients, biopsy of the pelvic mass in three and by follow-up study in 23. Tumor marker study and CT at 3- and 6-month intervals were used for follow up, which in most patients lasted for 18 to 24 months. Where either 1) increased tumor marker, 2) increased size of masses or lymph nodes, as seen on CT, or 3) decreased size of masses and lymph nodes after radiation therapy and chemotherapy was noted, it was considered that the condi- tion had recurred. In addition, the location and extension of recurrent mass- es or metastatic lymph nodes were analyzed for surgical extirpation and determination of radiation portal. RESULTS In 18 patients, recurrence was confirmed by pathologic examination and follow-up study. CT revealed three false- positive cases and four false negatives, while on PET there Table 1. Results of CT and PET for the Detection of Recur- rent Uterine Cervical Cancer CT PET TP 14 18 FP 3 1 FN 4 0 TN 15 17 Sens. Spec. Accu. (%) (%) (%) 77.8 83.3 100 94.4 80.5 97.2 Note. TP = true positive, FP = false positive, FN = false negative, TN = true negative, Sens = sensitivity, Spec. = specificity, Accu. = accuracy A B Fig. 1. A 39-year-old woman who had undergone radical hysterectomy due to uterine cervical carcinoma. A. Enhanced CT scan shows soft tissue mass on the left pelvic side wall (arrow). B. PET scan shows no hypermetabolic site in the pelvis. Since no interval change was seen during follow-up study, we concluded that this was a case of postoperative fibrosis. The highly metabolic lesion in left abdomen (arrow) is due to artifactual accumulation of FDG in as- cending colon. 52 Korean J Radiol 1(1), March 2000