Lancet Obstet Gynaecol
Can molecular imaging close the diagnostic gap for endometriosis?
Clinical takeaway: A novel targeted molecular imaging scan showed strong agreement with surgical diagnosis and may offer a future non‑invasive option for detecting superficial peritoneal endometriosis, where ultrasound and MRI frequently miss disease.
Early and accurate diagnosis of endometriosis remains challenging, particularly for superficial peritoneal disease. Conventional imaging frequently misses these lesions, contributing to long diagnostic delays and reliance on diagnostic laparoscopy.
This exploratory phase 2 study (DETECT) evaluated maraciclatide, a targeted molecular imaging agent designed to highlight abnormal blood vessel growth associated with endometriosis. The scan was performed before surgery and compared with operative findings.
Twenty patients with suspected or confirmed endometriosis underwent imaging, and 19 proceeded to surgery. Imaging and surgical findings were concordant in 16 of 19 cases (84%), with endometriosis visualized in 14 of 17 surgically positive patients.
Notably, no false-positive scans were reported. The technique detected lesions across subtypes, including superficial peritoneal endometriosis, which accounts for roughly 80% of laparoscopically diagnosed disease, and identified two cases of thoracic endometriosis.
The radiotracer was well tolerated, and patient acceptability was high. Although limited by a small sample size and single‑center design, the findings suggest targeted molecular imaging could help address a key diagnostic gap and may eventually support non‑invasive disease monitoring.
“Superficial peritoneal endometriosis, the most prevalent subtype of endometriosis, currently evades reliable detection, leaving women no choice for diagnosis other than invasive surgery," said study investigator Krina Zondervan of University of Oxford. "If these results are confirmed in larger phase 3 studies, imaging with maraciclatide could transform clinical research and practice and potentially empower the development of treatments for women across the globe.”
Source: Gibbons T, et al. (2026, April 29). Lancet Obstet Gynaecol Womens Health. Assessment of endometriosis angiogenesis using 99mTc-maraciclatide imaging (DETECT): a single-centre, exploratory, open-label, non-randomised, phase 2 study