Value of FDG PET/CT in Patients with Treated Ovarian Cancer and Raised CA125 Serum Levels

• Published in: Molecular imaging and biology 2012-02, Vol.14 (1), p.123-129
• Main Authors: Palomar, Azahara, Nanni, Cristina, Castellucci, Paolo, Ambrosini, Valentina, Montini, Gian Carlo, Allegri, Vincenzo, Pettinato, Cinzia, Al-Nahhas, Adil, Soriano, Angel, Grassetto, Gaia, Rubello, Domenico, Fanti, Stefano
• Format: Article
• Language: English
• Subjects: Adult; Age; Aged; Aged, 80 and over; Area Under Curve; CA-125 Antigen - blood; Carcinoma; Chemotherapy; Computed tomography; Data processing; Female; Fluorodeoxyglucose F18; Humans; Imaging; Medicine; Medicine & Public Health; Middle Aged; Multimodal Imaging - methods; Ovarian cancer; Ovarian Neoplasms - blood; Ovarian Neoplasms - diagnostic imaging; Ovarian Neoplasms - therapy; Positron emission tomography; Predictive Value of Tests; Prognosis; Radicals; Radiology; Radiopharmaceuticals; Research Article; Retrospective Studies; ROC Curve; Serum levels; Statistical analysis; Surgery; Tomography, X-Ray Computed; Tumors; Young Adult
• ISSN: 1536-1632; 1860-2002
• DOI: 10.1007/s11307-010-0468-9

Purpose Patients treated for ovarian cancer are usually referred for 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (FDG PET/CT) in case of increased Carcinoma Antigen 125 (CA125) but negative conventional imaging. However, there is not enough in the literature to support the value of FDG PET/CT in this context. This study aimed to assess role of FDG PET/CT in a cohort of patients with treated ovarian cancer and correlate the results with serum levels of CA125. Procedures We retrospectively studied 175 patients, mean age 65.2 years (range 24–88 years) who had radical treatment for ovarian cancer (chemotherapy, surgery or combination). The patients had a standard FDG PET/CT and measurement of serum CA125 within a month of the scan. PET/CT was considered positive if demonstrated areas of abnormally increased metabolic activity unrelated to physiological distribution, on the basis of a visual analysis. The results of PET/CT imaging were compared to the level of CA125, and receiver operating characteristic (ROC) curves were plotted and area-under-the curve (AUC) statistics were computed. Cytologic or histologic data or clinical and imaging follow-up were taken as gold standard. Results Patients were divided into five groups based on CA125 values. The average level of CA125 was 107.7 (range 3–867, SD 166.1). PET/CT was positive in 125/175 cases (71.4%), mean value of CA125 132.2 (SD 182.9) and negative in 50/175 (28.6%), mean value of CA125 46.4 (SD 89.3). In descriptive ROC analyses, the discriminatory power of this marker was relatively high (AUC statistics 0.77, range = 0.703–0.8). The optimal cut-off point of CA125 after treatment to reflect active disease on PET/CT was 18 U/mL achieving a detection rate of 85.6%. There was no relation between PET/CT negativity and the histological type of the tumor. Conclusion PET/CT was able to detect active disease at relatively low levels of CA125, thereby facilitating the early diagnosis of recurrence or residual disease. Also in patients with low CA125 levels (