A new approach to diagnosing thoracic endometriosis

Endometriosis is where cells similar to those in the lining of the womb grow in other parts of the body. It affects up to 1.5 million people in the UK.

Endometriosis is usually found in areas of the body around the womb but, rarely, it can be found outside the pelvis. Thoracic endometriosis is when endometriosis is found in the chest. It affects up to 12 % of people who have endometriosis in their pelvis.

It can take up to a year and a half to diagnose thoracic endometriosis after symptoms start. Diagnosis is often delayed because healthcare professionals are unaware of the condition.

The most common way healthcare professionals find out someone has thoracic endometriosis is when they have a catamenial pneumothorax. This is when air leaks into the space around the lungs, in the 3 days before or after a woman’s period each month.

At the moment there is no way of diagnosing thoracic endometriosis without surgery.

A possible new way of diagnosing thoracic endometriosis is to use 99mTc-maraciclatide. 99mTc-maraciclatide is a synthetic molecule that attaches itself to patches of endometriosis. It has a radioactive atom attached to it which can be detected from outside the patient using a type of CT scanner called a SPECT-CT scanner. The scanner produces images of the patient showing where the 99mTc-maraciclatide is. This should show where in the chest there is endometriosis.

Project aims

The aim of this project is to find out how effective 99mTc-maraciclatide is in identifying thoracic endometriosis, in female patients who have thoracic endometriosis, suspected thoracic endometriosis or catamenial pneumothorax.

We aim to test the technique on 15 patients who come to North Bristol NHS Trust with known or suspected thoracic endometriosis, or catamenial pneumothorax, over an 18-month period.

What we hope to achieve

A large clinical trial is planned, to find out how effective 99mTc-maraciclatide is at detecting endometriosis. If our study is successful, patients with thoracic endometriosis – endometriosis in the chest – could be included in the trial.

If the new technique works, it will be the first test for thoracic endometriosis that doesn’t involve surgery.