Assessment of Gynecologic Malignancy (Recurrent Ovarian Carcinoma) by Positron Emission Tomography

Kang, Soon Beom; Lee, Chul Min; Kim, Yong Beom; Kim, Jae Weon; Park, Noh Hyun; Song, Yong Sang; Chung, June Key; Lee, Hyo Pyo

Abstract

BACKGROUND: Recurrence of ovarian carcinoma is difficult to diagnose by current diagnostic modalities. Positron emission tomography(PET) might be useful for detecting recurrence of ovarian carcinoma by producing images which reflect biochemical change of tissues rather than their physical characteristics using a positron emitting glucose analog, 2-[18F]-fluoro-2-deoxy-D-glucose(FDG), because glycolysis is increased in malignant tissue.
OBJECTIVE
To determine if PET is sensitive for the detection and demonstration of recurrence of ovarian carcinoma and to compare detectability of PET to that of serum CA-125 and CT/MRI. MATERIALS & METHODS: Whole body PET scan was performed in thirty patients with epithelial ovarian carcinoma from March, 1996 to March, 1998 in Seoul National University Hospital. All patients received cytoreductive surgery and combination chemotherapy. The recurrence of ovarian carcinoma was declared by surgico-pathologic evidence or abnormal elevation of serum CA-125 level. CTI/Siemens scanner was used for PET. Ten mCi(370 MBq) of FDG was injected intravenously before whole body scan was obtained from the head to the lower leg. Regional transmission and emission scan was also obtained for areas of tumor. Serum CA-125 levels and CT/MRI findings by the time of PET were matched with PET results. Correlation analysis was performed between each diagnostic modalities and the recurrence of ovarian carcinoma.
RESULTS
Ovarian carcinomas were recurred in twelve out of thirty patients. FDG PET detected the recurrence of ovarian carcinoma in ten patients(sensitivity = 66.7%; specificity = 86.7%; contingency coefficient, CC = 0.48; p = 0.003), and better than CA-125(sensitivity = 75.0%; specificity = 75.0%; CC = 0.28; p > 0.05) and CT/MRI(sensitivity = 38.5%; specificity = 57.1%; CC = 0.01; p > 0.05).
CONCLUSION
FDG PET accurately predicted the recurrence of ovarian carcinoma and is a useful adjunctive diagnostic method. A prospective case-control study with more patients might be needed in the future.