Optimizing Necrotizing Otitis Externa Management: The Role of PET-CT in Antibiotic Stewardship

Objective: To optimize antibiotic regimens in necrotizing otitis externa (NOE) and skull base osteomyelitis (SBO) and evaluate the role of positron emission tomography-computed tomography (PET-CT) in disease monitoring. Study design: A 2-cycle quality improvement project comparing traditional imaging (CT/MRI) with PET-CT-guided management. Setting: Tertiary referral center. Patients: Patients with NOE were retrospectively reviewed in the CT/MRI cohort (2015 to 2018) and prospectively assessed in the PET-CT cohort (2022 to 2024). Nineteen patients were included in the first cycle, and 14 in the second. Intervention(s): A revised management pathway incorporating PET-CT for treatment response assessment was implemented. Oral ciprofloxacin regimens were standardized in the PET-CT cohort, with a preference for higher-dose, shorter-duration therapy. Main outcome measures: Antibiotic duration, relapse rates, and PET-CT efficacy in guiding treatment cessation. Results: Patients in the PET-CT cohort received significantly shorter oral ciprofloxacin courses (median: 8 vs. 40 wk, P <0.001) without increased relapse rates. PET-CT confirmed resolution in 64% of cases, enabling antibiotic discontinuation. Relapses occurred in 21% of the CT/MRI cohort but were absent in the PET-CT group ( P =0.11). Higher ciprofloxacin doses (750 mg BID) were more frequently used in the PET-CT cohort ( P =0.002), yet this did not increase antibiotic-related complications ( P =1.00). Mortality rates remained comparable between cohorts (7% PET-CT vs. 11% CT/MRI). PET-CT provided superior real-time infection monitoring, preventing unnecessary prolonged antibiotic courses. Conclusions: PET-CT effectively guided treatment cessation, reducing antibiotic exposure without compromising clinical outcomes. A higher-dose, shorter-duration ciprofloxacin regimen did not increase relapse rates, suggesting that a more intensive yet time-limited antimicrobial approach can be safely implemented. These findings support PET-CT as a valuable tool in NOE/SBO management, reinforcing its role in optimizing antibiotic stewardship.