1024 A Case-Controlled Series Examining the Utility of Nuclear Medicine Imaging in The Diagnosis and Management of Malignant Otitis Externa

Introduction This study aimed to assess whether combination modality imaging (CT, and/or Technetium/Gallium) had any additional benefits over single modality imaging (CT) in the management of malignant otitis externa (MOE). Method A six-year retrospective case-controlled series was performed including 73 patients presenting with a potential diagnosis of MOE. Results CT imaging was undertaken in 69/73 patients, and of these the CT confirmed the diagnosis in 58% (40/69). Of the 42% (29/69) of CT negative patients, 25 underwent Technetium scanning, revealing 40% (10/25) to be negative. These patients were discharged on a short course of topical and oral therapy with no disease recurrence. Gallium scan results, performed at the end of treatment, were more inconsistent, with 47% (25/53) of imaging still positive despite extended intravenous/oral/topical therapy. However,40% (10/25) of these had their therapy stopped without any further disease relapse. Conclusions Combination modality imaging, with CT and Technetium, did infer additional benefit over single modality imaging using CT. However, this was not the case for Gallium scanning, used to determine treatment end, which seemed to be poorly representative of residual disease presence. This study was utilised to provide a management algorithm to guide future practice.