[68Ga]Ga-FAPI-04 PET/CT in a patient with endometriosis: a potential game changer?

A 43-year-old woman with a known history of endometriosis presented with dysmenorrhea, dyschezia, and hematochezia.She had previously undergone a hysterectomy, during which infiltrative endometriosis in the bowel was identified.To guide further treatment decisions, a magnet resonance imaging (MRI) was performed, confirming bowel involvement and revealing a circumscribed lesion infiltrating the sigmoid colon.Due to persistent symptoms, the patient opted for surgery.For preoperative planning, a fibroblast activation protein inhibitor (FAPI) positron emission tomography/ computed tomography with [ 68 Ga]Ga-FAPI-04 was conducted.PET images, acquired 10 min after administration 148 MBq of [ 68 Ga]Ga-FAPI-04, showed intense tracer uptake (Fig. A; left column: maximum intensity projection; right column: axial slices of PET/CT fusion and PET; big arrow head: endometriosis in the sigmoid colon, SUVmax 9.8) at the same location as the MRI finding (Fig. B, axial and sagittal slices of contrast enhanced T1-weighted fat saturated sequence), thus confirming the MRI result.Additionally, the PET scan revealed intense uptake in the left