Maryam Shahbazi - Nuclear Medicine and Molecular Imaging Research Center, Namazi Teaching Hospital, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Tahereh Poordast - Department of Obstetrics and Gynecology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Nahid Masoudi - Nuclear Medicine and Molecular Imaging Research Center, Namazi Teaching Hospital, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Mahdi Haghighatafshar - Nuclear Medicine and Molecular Imaging Research Center, Namazi Teaching Hospital, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

Introduction: Endometriosis is a gynecological disease and disorder that occurs when endometrial cells are shed through the fallopian tubes and are implanted on the surfaces of pelvis and abdomen. They form lesions that respond to hormones of the menstural cycle and will stimulate inflammation. It is controversial whether [۹۹mTc]Tc-RBC scan would be sufficient for localizing bleeding sites. This study evaluated the value of [۹۹mTc]Tc-RBC in diagnosing endometriosis. Methods: Twenty patients were included in the study for endometriosis localization. Between the ۲nd and the ۵th days of menstruation, when the lesions were highly activated, [۹۹mTc]Tc-RBC scan was performed and compared with TVUS, pelvic MRI and laparoscopic surgery findings. Scans of the patients were reported by two nuclear medicine specialists who were blind to patients’ history. Results: The patients’ age range was ۲۱-۴۸ years (mean age: ۳۵±۸.۷۹). The sensitivity, specificity, positive predictive value and negative predictive value for the right pelvic bleeding sites were ۷۳.۳%, ۸۰.۰%, ۹۱.۷% and ۵۰%, respectively while the corresponding indices on the opposite pelvic site were find to be ۸۷.۵%, ۷۵.۰%, ۹۳.۰% and ۶۰%, respectively. Conclusion: Radiolabeled red blood cell scintigraphy has the potential to be used as an alternative procedure for diagnosing endometriosis.

Red blood cell, Scintigraphy, Endometriosis, Tc-۹۹m