TY - JOUR T1 - Imaging of Gynecologic Tumors: Comparison of <sup>11</sup>C-Choline PET with <sup>18</sup>F-FDG PET JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1051 LP - 1056 VL - 44 IS - 7 AU - Tatsuo Torizuka AU - Toshihiko Kanno AU - Masami Futatsubashi AU - Hiroyuki Okada AU - Etsuji Yoshikawa AU - Fumitoshi Nakamura AU - Munetaka Takekuma AU - Makoto Maeda AU - Yasuomi Ouchi Y1 - 2003/07/01 UR - http://jnm.snmjournals.org/content/44/7/1051.abstract N2 - This study was designed to compare the value of PET using 11C-choline with that of PET using 18F-FDG for the diagnosis of gynecologic tumors. Methods: We examined 21 patients, including 18 patients with untreated primary tumors and 3 patients with suspected recurrence of ovarian cancer. 11C-choline PET and 18F-FDG PET were performed within 2 wk of each other on each patient. The patients fasted for at least 5 h before the PET examinations, and PET was performed 5 min (11C-choline) and 60 min (18F-FDG) after injection of each tracer. PET images were corrected for the transmission data, and the reconstructed images were visually analyzed. Then, the standardized uptake value (SUV) was calculated for quantitative assessment of tumor uptake. PET results were compared with surgical histology or &gt;6 mo of clinical observations. Results: Of 18 untreated patients, 11C-choline PET correctly detected primary tumors in 16 patients, whereas 18F-FDG PET detected them in 14 patients. In 1 patient with small uterine cervical cancer and 1 diabetic patient with uterine corpus cancer, only 11C-choline PET was true-positive. Both tracers were false-negative for atypical hyperplasia of the endometrium in 1 patient and were false-positive for pelvic inflammatory disease in 1 patient. For the diagnosis of recurrent ovarian cancer (n = 3), 11C-choline PET and 18F-FDG PET were true-positive in 1 patient, whereas neither tracer could detect cystic recurrent tumor and microscopic peritoneal disease in the other 2 patients. In the 15 patients with true-positive results for both tracers, tumor SUVs were significantly higher for 18F-FDG than for 11C-choline (9.14 ± 3.78 vs. 4.61 ± 1.61, P &lt; 0.0001). In 2 patients with uterine cervical cancer, parailiac lymph node metastases were clearly visible on 18F-FDG PET but were obscured by physiologic bowel uptake on 11C-choline PET. Conclusion: The use of 11C-choline PET is feasible for imaging of gynecologic tumors. Unlike 18F-FDG PET, interpretation of the primary tumor on 11C-choline PET is not hampered by urinary radioactivity; however, variable background activity in the intestine may interfere with the interpretation. ER -