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

Estrogen receptor (ER) overexpression in endometriotic lesions will be assessed using the Standardized Uptake Value (SUV) on preoperative [18F]-FES PET/CT imaging. Each lesion's SUV will be quantified and compared within patients and between groups with high pain levels (VAS ≥ 4) and low or no pain (VAS < 4). ER overexpression is defined as increased [18F]-FES uptake compared to background levels. The correlation between SUV values and pain severity will be analyzed to determine whether ER overexpression is associated with symptomatic burden. Higher SUV values indicate greater ER expression.

Lesions were analyzed using immunohistochemistry (IHC) and in situ hybridization to characterize receptor expression patterns (ERα, ERβ, GPER) and staining intensity. Tissue microarrays (TMA) from 20 patients were used to standardize analysis. IHC staining was performed with specific antibodies against ERα (SP1) and ERβ (CWK-F12 (DSHB)), while in situ hybridization was conducted using Bio-Techne probes targeting ESR1, ESR2, and GPER mRNA. Staining intensity and receptor expression were assessed for each lesion and compared across anatomical locations. Correlation with [18F]-FES PET/CT imaging and clinical symptomatology was also evaluated.

The sensitivity of [18F]-FES PET/CT in detecting superficial and deep endometriotic lesions will be compared to that of MRI. Lesions will be classified based on their anatomical location. Sensitivity will be calculated as the proportion of true positive lesions detected by each imaging modality, using surgical and histopathological findings as the reference standard. The diagnostic performance of PET/CT and MRI will be analyzed for different lesion types and locations to assess their respective accuracy in detecting endometriosis.

The association between [18F]-FES standardized uptake value (SUV) intensity, estrogen receptor (ER) expression assessed by immunohistochemistry (IHC), and pain severity will be analyzed. ER expression will be evaluated using specific antibodies for ERα and ERβ, and quantified based on staining intensity. Pain severity will be assessed using the Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst possible pain). Correlations will be determined to assess the relationship between tracer uptake, receptor expression, and pain perception

Estrogen receptor expression (ERα, ERβ, GPER) will be assessed in endometriotic lesions using immunohistochemistry (IHC) and in situ hybridization (ISH). Staining intensity will be scored semi-quantitatively (e.g., 0 to 3). Pain severity will be measured using the Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst possible pain). A correlation analysis will be conducted to evaluate the relationship between receptor expression scores and VAS scores. The unit of measure will be the correlation coefficient between IHC/ISH scores and VAS units (0-10 scale).

Estrogen receptor mRNA expression (ESR1, ESR2, GPER) will be quantified in endometriotic lesions using in situ hybridization (ISH). Expression levels will be evaluated based on signal intensity scores derived from probe hybridization. Pain severity will be measured using the Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst pain). A statistical correlation will be assessed between the mRNA expression signal intensity scores and VAS values. The unit of measure will be the correlation coefficient quantifying the relationship between receptor expression levels and reported pain intensity.