Feasibility of short-course antibiotic therapy for surgically treated brain abscess guided by 4-week MRI.

Brain abscess is a life-threatening intracranial infection typically managed with surgery followed by prolonged intravenous antibiotics. This study aimed to evaluate the feasibility of a short-course intravenous antibiotics regimen after surgery and to assess the utility of 4-week MRI as a biomarker to guide treatment discontinuation. This retrospective study included 60 patients who underwent surgery for bacterial brain abscess at a tertiary center between 2011 and 2024. A scheduled 4-week MRI including diffusion-weighted imaging was performed to assess radiologic resolution. The clinical outcomes, including recurrence, treatment-related adverse events (AEs), and 6-month functional outcomes, were investigated. Patients were categorized into short-course and conventional groups according to antibiotic duration (< 35 vs. ≥35 days), based on the cut-off value for predicting the development of severe AEs. There was no recurrence in both groups. Severe AEs occurred in 22 patients (36.7%), and the most common severe AE was neutropenia followed by severe drug eruption. Patients in the short-course group had significantly fewer severe AEs (P = 0.007) and better functional outcomes at 6 months (P = 0.032) compared to the conventional group. Prolonged antibiotic use was the only independent risk factor for severe AEs (P = 0.036). 4-week MRI was performed in 42 patients (70.0%), and all 25 patients in the short-course group underwent the 4-week MRI and met the resolution criteria. A short-course intravenous antibiotics therapy following surgical evacuation was effective and safe when guided by MRI at 4 weeks, which served as a reliable indicator to confirm resolution and safe treatment discontinuation.