Benign ovarian and endometrial uptake on FDG PET-CT: patterns and pitfalls

Abstract

Increased ovarian or endometrial uptake may cause a dilemma in the interpretation of whole body F18-fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging or even misdiagnosis of malignant disease. Knowledge of benign FDG uptake of the ovaries and uterus is important for daily practice of nuclear medicine radiologists. Increased uptake in the ovaries or uterus indicates a pathologic or neoplastic process in postmenopausal patients. In premenopausal women, increased ovarian or endometrial uptake can be functional or malignant. Benign functional uptake of premenopausal ovaries or uterus is related to the menstrual cycle; therefore, information about the patient's menstrual status is crucial for interpretation. In addition, correlation with computed tomography (CT), especially diagnostic CT acquired at the same time of PET/CT is very useful in clarifying the location of the uptake and the existence or disappearance of the discrete lesion. Increased ovarian uptake may also be identified in histologically different benign tumor entities. Nonmenstrual-related endometrial uptake may be present in many benign diseases as well.

F-18 FDG PET/CT findings of metastatic ovarian tumors from gastrointestinal tract origin

“…Physiologic ovarian FDG uptake is usually seen in premenopausal patients, in whom it is related to their menstrual cycle (Kim et al 2005(Kim et al , 2010Lerman et al 2004;Liu 2009). In postmenopausal patients, increased ovarian FDG uptake usually suggests malignancy.…”

MR-PET fusion imaging in evaluating adnexal lesions: a preliminary study

“…Inoltre, nell'ambito delle formazioni benigne, alla valutazione TC/PET si era documentato un falso positivo, risultato successivamente essere una cisti endometriosica. In tal caso è ipotizzabile che l'elevata captazione del radiofarmaco nel contesto della formazione (SUV max 3,6; paziente 1; Tabella 2) potesse esser dovuta all'elevato metabolismo espresso dalle cellule infiammatorie [22].…”

“…Per quanto riguarda i linfonodi il limite della RM è rappresentato dal ristretto FOV di acquisizione nella valutazione della pelvi, potendo valutare le sole stazioni pelviche e risultando perotic cyst. In this case, the strong uptake of contrast material inside the lesion (SUV max 3.6; patient 1, Table 2) was probably caused by the accelerated metabolism of inflammatory cells [22].…”

Diagnostic imaging using positron emission tomography for gynecological malignancy

“…First, normal ovaries can be affected by physiological conditions such as inflammation and the menstrual cycle, as with normal endometrium. 35,36 Increased uptake of F-FDG PET/CT had low diagnostic value in differentiating between borderline and benign tumors due to low 18 F-FDG uptake, leading to false-negative results. 81 Moreover, the combination of PET with modalities such as US and MRI did not add additional diagnostic value, and had almost the same sensitivity and specificity as US and MRI without PET, suggesting that Contrast-enhanced CT has been widely used as the standard imaging modality for the staging of ovarian cancer.…”