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

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.

• Characterization of Lesion Staining by Immunohistochemistry and In Situ Hybridization: Intensity and Receptor Expression by Anatomical Location. [Time frame: From tissue collection at surgery to completion of immunohistochemical and in situ hybridization analyses (approximately 4 weeks post-surgery).]
• Sensitivity of [18F]-FES PET/CT Compared to MRI for Diagnosing Superficial and Deep Endometriotic Lesions by Anatomical Location. [Time frame: From completion of MRI and [18F]-FES PET/CT imaging (performed within 4 weeks prior to surgery) to histopathological analysis of lesions obtained during surgery (within 4 weeks post-imaging); total assessment period: up to 8 weeks per participant]
• Association Between [18F]-FES SUV Intensity, Estrogen Receptor Expression (IHC), and Pain Severity (VAS Score) [Time frame: From the date of [18F]-FES PET/CT imaging (≤4 weeks before surgery) to the date of surgery and completion of pain assessments (VAS and BPI) and histopathological analysis of surgical samples; total duration of assessment per participant : up to 8 weeks]
• Correlation Between Estrogen Receptor Expression in IHC/ISH and Pain Intensity (VAS) in Endometriosis [Time frame: From surgery (biopsy collection) to completion of pain assessment and histological analysis; up to 8 weeks.]
• Correlation Between Estrogen Receptor mRNA Expression and Pain Intensity (VAS) in Endometriosis [Time frame: From surgery (biopsy collection) to completion of ISH and VAS assessments; up to 8 weeks.]