A new molecular imaging scan that uses an injectable tracer to make endometriosis lesions "light up" on routine SPECT‑CT scans is giving researchers hope that the disease could someday be diagnosed and tracked without heading straight to surgery.
Early findings suggest the technique can reveal very small, early lesions that standard ultrasound and MRI often miss, raising the possibility of a diagnosis path that does not always rely on invasive laparoscopy.
Small phase 2 study showed lesions matched surgery
The DETECT phase 2 trial, an exploratory, single‑centre study of about 20 people, found that uptake of 99mTc‑maraciclatide on SPECT‑CT closely matched what surgeons later saw during laparoscopy in most cases, as published in The Lancet.
Among the 19 participants who completed both procedures, the authors reported concordance between imaging and laparoscopy in 16 cases and noted that the tracer visualized disease that routine imaging had missed. Investigators described the results as preliminary but promising for detecting superficial peritoneal endometriosis.
How the tracer works and who made it
The tracer, 99mTc‑maraciclatide, binds to αvβ3 integrins, proteins associated with new blood‑vessel growth in inflamed tissue, so developing lesions appear as hotspots on scans, according to the University of Oxford.
Serac Healthcare, which is developing the agent, and the study team emphasize that the test runs on widely available SPECT‑CT equipment. That could make broader rollout simpler than building entirely new imaging infrastructure.
Limits and questions researchers flagged
The study also highlighted some practical snags. Scarring near and around the bladder masked signal in three participants, and the authors suggested exploring ways to limit bladder activity during scanning in future protocols, as noted in The Lancet.
Because DETECT was small and run at a single centre, clinicians stressed that larger, multi‑centre validation is needed before the scan could be considered a routine diagnostic alternative to laparoscopy.
A patient’s long road to diagnosis
The stakes are personal for patients like Latia Lee, who told Spectrum News she had symptoms for 23 years before finally getting a diagnosis.
Over that time, she underwent multiple surgeries, including an eight‑hour operation, bowel resection and diaphragm surgery. "I don't think people understand, like, the severity of it," Lee said. She added that a reliable non‑invasive scan could spare others years of suffering and complex operations.
Next steps: phase 3 and regulators
Serac and the Oxford team say they are moving to larger Phase 3 trials, with cohorts planned in the U.K. and the U.S. The company reports positive feedback from an FDA end‑of‑phase II meeting and Fast Track designation for the tracer, according to Serac Healthcare.
The trial registry entry for related studies is listed on ClinicalTrials.gov, and the groups say multi‑centre work is planned to start later this year.
Why this would matter
Endometriosis affects roughly one in 10 people of reproductive age, and diagnostic delays commonly stretch for years, a problem highlighted in recent clinical reviews and commentary. As experts and the study authors note, a validated, repeatable imaging test could shorten diagnostic delays, provide objective monitoring of disease activity and create measurable endpoints for new treatments, according to BMJ.
