Suk Hee Heo MD, Presenter: Nothing to Disclose

Jeong Jun Min, Abstract Co-Author: Nothing to Disclose

Yong-Yeon Jeong MD, Abstract Co-Author: Nothing to Disclose

Jin Woong Kim MD, Abstract Co-Author: Nothing to Disclose

Sang Soo Shin MD, Abstract Co-Author: Nothing to Disclose

Heoung-Keun Kang MD, Abstract Co-Author: Nothing to Disclose

To compare PET-CT findings of pathologic 18F-FDG ovarian uptake and those of physiologic ovarian uptake in premenopausal patients with underlying malignancy.

Seventy consecutive premenopausal patients with underlying malignancy (20 thyroid cancers, 15 gastric cancers, 13 colorectal cancers, 12 breast cancers, 10 uterine cervical cancers) were retrospectively reviewed. Of 70 patients, 12 patients had confirmed ovarian metastasis and 58 patients diagnosed functional normal ovary. The diagnosis was based on surgery (n=14) or imaging studies and clinical follow-up (n=56). PET images and unenhanced-CT images were evaluated by a nuclear medicine physician and a radiologist, respectively. On PET images, location (unilateral, bilateral), SUV, pattern of ovary uptake (focal nodular, discoid, diffuse patchy), maximal length of the uptake, and presence of endometrial uptake were recorded. On unenhanced CT images, attenuation and maximal length of the ovary corresponding to FDG uptake were recorded. Student T-test was used for statistical analysis.

Bilaterality was more often found in patients with pathologic uptake (6/12, 60%) than those with physiologic uptake (4/58, 6.9%). There was no statistically significant difference between mean SUVs of pathologic uptake (6.6 ± 4.1) and physiologic ovarian uptake (6.0 ± 2.4) (P > 0.05). Diffuse patchy pattern was found in 9 of 12 patients (75%) with pathologic ovarian uptake whereas it was only seen in 2 of 58 (3.5%) with physiologic ovarian uptake (P < 0.001). Endometrial uptake showed in 9 of 12 patients (75%) with pathologic uptake and in 27 of 58 patients (46.5%) with physiologic ovarian uptake (P = 0.071). Mean attenuation of the ovary with pathologic and physiologic uptake was 33.5 ± 11.8 and 19.1 ± 7.1, respectively (P < 0.001). Mean maximal length of the ovary with pathologic and physiologic uptake was 5.0 ± 2.6 cm and 3.3 ± 0.7 cm, respectively (P < 0.001).

On PET-CT, bilateral and diffuse patchy ovarian uptake, higher mean attenuation, and larger size of the ovary could be helpful findings in differentiating pathologic uptake such as metastasis from physiologic ovarian uptake in premenopausal oncologic patients.

In oncologic patients, it is important to be familiar with characteristic patterns, location, and size of pathologic and physiologic uptake on PET-CT images to avoid misinterpretation.

Heo, S, Min, J, Jeong, Y, Kim, J, Shin, S, Kang, H, Pathologic 18F-FDG Ovarian Uptake in Patients with Underlying Malignancy on FDG PET-CT: Differentiation from Physiologic Ovarian Uptake.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9014287.html