Use of a New Diagnostic Tool in the Detection and Characterization of Endometriosis Lesions

18F]-FES PET in the Detection and Characterization of Endometriosis Lesions

Diagnostic wandering is one of the characteristics of endometriosis due to great anatomical and clinical variability but also due to poorly relevant diagnostic examinations. [18F]-FES PET/CT could on the one hand improve diagnosis by showing greater sensitivity than MRI and on the other hand make it possible to quantify and characterize the expression of ER from diagnosis and thus helping to guide therapeutic care. We will thus attempt to correlate the intensity of [18F]-FES PET/CT with the expression of estrogen receptors and the intensity of pain.

Endometriosis is a chronic estrogen-dependent gynecological condition that leads to impaired overall quality of life due to infertility and associated pain. Diagnostic wandering is one of the characteristics of endometriosis due to great anatomical and clinical variability but also due to poorly relevant diagnostic examinations. There are several anatomo-clinical pathological entities. Thus, its painful symptoms vary greatly in its location and intensity. MRI, the reference examination for diagnosis but operator dependent, shows imperfect sensitivity. The diagnosis and characterization of lesions must therefore be improved. We know that 17β-estradiol, a key hormone for lesion growth, can also be produced locally by endometriotic tissue. The hypothesis according to which this local accumulation of estrogens plays an important role in the development of lesions by modulating the expression of RE must be studied. The use of new tools to study estrogen receptor expression should be evaluated at diagnosis. A new examination, [18F]-FES PET/CT, could on the one hand improve diagnosis by showing greater sensitivity than MRI and on the other hand make it possible to quantify and characterize the expression of the ER from the diagnosis and thus help to guide therapeutic care. [18F]-FES PET/CT is a non-invasive, operator-independent method that visualizes and quantifies ER expression in multiple tumors. Some studies have shown that [18F]-FES uptake correlates well with ER expression measured by immunohistochemistry staining. We will thus attempt to correlate the intensity of [18F]-FES PET/CT with the expression of estrogen receptors and the intensity of pain.

Inclusion Criteria:

Cases:

- Painful patients with a VAS ≥ 4 treated surgically for painful symptoms related to endometriosis;

Controls:

• Patient with a VAS < 4 treated surgically for endometriosis in the context of infertility;
• Age > 18 years;
• Patient who provided informed consent;
• Patients who underwent a preoperative MRI and were not contraindicated for [18F]-FES PET/CT;
• Patient who underwent surgery mid-cycle;
• Affiliation to a social security scheme

Exclusion Criteria:

• Patient treated for endometriosis without surgery;
• Pregnant patient
• Patient taking hormone therapy
• Menopausal patient
• Hypersensitivity to the active substance (Fluoroestradiol (18F)) or to any of the excipients
• Patient under legal protection
• Claustrophobic patient