The study will aim to show that there is a superiority of 18F-FDG PET/CT compared to labeled leukocyte scintigraphy in patients with a malignant otitis externa.

The management of malignant otitis externa (MEO) is a major issue in patients who are often polypathological and fragile. Appropriate antibiotic therapy must be started quickly after the diagnosis is made and followed for a period of at least 6 weeks. Imaging plays a major role in assessing the extent of the infection and especially healing, after 6 weeks of antibiotic therapy. The persistence of an infection at the end of the treatment, observed in imaging, will allow a change of antibiotic line. This study consists in studying in a population affected by an OEM, the performance of PET/CT with 18F-FDG compared to scintigraphy with labeled leukocytes. The usefulness of the latter in the follow-up of the pathology after antibiotic therapy has already been proven in the literature. The study will aim to show that there is a superiority of 18F-FDG PET/CT compared to labeled leukocyte scintigraphy.

Inclusion Criteria:

• patients with malignant otitis externa who received a 18F-FDG positron emission tomography and a labelled leukocyte scintigraphy

Exclusion Criteria:

• patients who refuse to have their imaging data used

Patients who underwent an 18F-FDG positron emission tomography examination and a labeled leukocyte scintigraphy before and after antibiotic therapy in the case of management of an malignant otitis externa.