Treatment Response Evaluation in Necrotizing Otitis Externa Using 18 F-FDG-PET Imaging

Area of Science:

• Nuclear Medicine
• Radiology
• Infectious Diseases

Background:

• Necrotizing otitis externa (NOE) poses diagnostic challenges in differentiating sterile inflammation from active infection.
• Accurate treatment response evaluation is crucial for managing NOE and preventing complications.

Purpose of the Study:

• To identify 18F-FDG-PET imaging features for improved treatment response evaluation in NOE patients.
• To differentiate between sterile inflammation and active infection using PET imaging.
• To predict recurrent disease after treatment.

Main Methods:

• Retrospective cohort study at a tertiary hospital.
• Inclusion of 20 NOE patients diagnosed between 2011 and 2022.
• Analysis of 18F-FDG-PET/CT parameters (SUVmax, SUVpeak, mean SUV, TLG) from pretreatment and end-of-treatment scans.

Main Results:

• End-of-treatment SUVmax and SUVpeak were significantly higher in patients with recurrent NOE (p=0.025).
• SUVpeak demonstrated 100% sensitivity and 67% specificity for predicting recurrence.
• Other parameters like mean SUV and TLG, and the difference between scans, were not significant predictors.

Conclusions:

• SUVpeak on end-of-treatment 18F-FDG-PET is a preferred parameter for evaluating NOE treatment response.
• High residual SUVpeak indicates a risk for recurrent disease, potentially requiring prolonged treatment.
• Low SUVpeak suggests a low risk of recurrence, allowing for safe treatment cessation.