The gold standard for diagnosing endometriosis is surgery. For the roughly 11 percent of American women who have the condition, that has meant years of pain, repeated failed scans, and ultimately going under the knife just to get a name for their suffering. A new imaging tool tested at the University of Oxford may make that ordeal unnecessary.
Endometriosis affects women between the ages of 15 and 44, and is especially common among women in their 30s and 40s. The condition can cause severe pain, heavy bleeding, fatigue, and fertility problems. Yet, women typically wait eight to 12 years for diagnosis, cycling through multiple doctor visits and inconclusive scans.
Now, researchers say a new non-invasive imaging technique could shorten the wait.
Detects Hardest to Diagnose Form of Endometriosis
Researchers from the University of Oxford, working with radiopharmaceutical company Serac Healthcare, recently published the Phase II trial findings in The Lancet Obstetrics, Gynaecology, & Women’s Health. The clinical trial evaluated a new imaging agent, maraciclatide (99mTc-maraciclatide), used in conjunction with a specialized CT scan to detect endometriosis, a common inflammatory disease where tissue similar to the lining of the womb grows outside the uterus, often in the pelvis.
The trial involved 20 women with suspected or confirmed endometriosis. Women were first scanned with maraciclatide and then underwent surgery to see if the first scans were accurate.
After surgery, it was confirmed that 17 of the women had endometriosis. The maraciclatide imaging missed three diagnoses and correctly diagnosed 14.
Maraciclatide imaging successfully identified superficial peritoneal endometriosis—a type of endometriosis that is very hard to diagnose—in nine out of 12 participants. Ten of the 12 participants had undergone traditional imaging 12 months before the study, and their endometriosis was missed on those scans.
Two women did not have endometriosis—a finding consistent with the maraciclatide imaging. One woman opted out of surgery, so her findings could not be confirmed. The study found no false positives.
It is the first time maraciclatide has been used to help identify the disease on scans. The radioactive tracer works by binding to a protein involved in the formation of new blood vessels, a process that plays a key role in the growth of endometriosis lesions. The tracer detected endometriosis in cases that conventional imaging had missed entirely, including early-stage disease.
Why Current Methods Fall Short
The findings suggest that maraciclatide could serve as a new, non-invasive test—especially for superficial peritoneal endometriosis, the most common and hardest type to detect with current methods, which include laparoscopic surgery, currently considered the “gold standard” for a definitive endometriosis diagnosis, according to Dr. Sara Kim, a gynecologist at Stony Brook Medicine in New York, and not involved in the study.
“So, for someone to be diagnosed with endometriosis, often times they need to undergo surgery,” she told The Epoch Times. “Which isn’t just something taken lightly.”
Conventional MRI often misses superficial endometriosis, which makes up about 80 percent of all cases, she said.
Dr. Armando Hernandez-Rey, a reproductive endocrinologist at Conceptions Florida in Miami, said that even at his practice, only 50 to 60 percent of patients with suspected endometriosis are accurately diagnosed, which is considered a high percentage.
If confirmed in larger studies, the new scan could help provide women with an explanation for their symptoms earlier, researchers say. It could also help monitor the disease and track patients’ responses to treatment.
Symptoms of endometriosis include severe period pain that prevents women from carrying out normal activities, heavy periods, and extreme tiredness. Additional signs may include pain in the lower abdomen, back, and pelvis, as well as discomfort when urinating or during bowel movements. Some women may experience pain during or after sex, or notice pain in other areas, such as the chest. Difficulties conceiving and feelings of low mood can also be indicative of underlying issues.
FDA Fast Track and the Road Ahead
In July 2024, the U.S. Food and Drug Administration granted fast-track status to 99mTc-maraciclatide as a diagnostic agent for superficial peritoneal endometriosis, a designation designed to accelerate the development and review of drugs that address serious conditions with unmet medical needs.
“With FDA Fast Track Designation and agreed Phase III study designs, we are now advancing to validate these findings in larger trials and progress to regulatory submission,” Serac Healthcare CEO David Hail said in a statement.