Prospective Trial of [18F]AlF-FAPI-74 for PET Imaging of Fibroblast Activation Protein in Patients With Endometriosis

The goal of this clinical trial is to learn whether \[18F\]AlF-FAPI-74 PET/CT can help detect endometriosis in adult women who are already scheduled for laparoscopy due to suspicion of deep infiltrating endometriosis or superficial peritoneal endometriosis. The main aims are: (i) How well does \[18F\]AlF-FAPI-74 PET/CT identify endometriosis lesions compared with findings during laparoscopy? (ii) Can PET/CT identify additional lesions that may not be seen on ultrasound or MRI? (iii) Can ultra-high-resolution NeuroEXPLORER PET/CT improve the detection of small lesions compared with standard PET/CT? Participants will: (i) Receive an intravenous injection of \[18F\]AlF-FAPI-74 followed by a PET/CT scan before their planned laparoscopy. (ii) Undergo their planned laparoscopy, during which PET findings will be compared with the surgical findings and where tissue is removed with laboratory analysis. (iii) Optionally undergo an additional NeuroEXPLORER PET/CT scan after the same tracer injection. (iv) Optionally undergo a second \[18F\]AlF-FAPI-74 PET/CT if participants started gonadotropin-releasing hormone (GnRH) treatment after their first scan to investigate whether tracer uptake in endometriosis lesions changes during treatment.