Reevaluating routine imaging: clinical utility of postoperative CT after stereotactic brain biopsy

OBJECTIVE: Stereotactic brain biopsy (SBB) is a widely used and generally safe diagnostic procedure. However, the utility of routine postoperative CT scans to screen for hemorrhage remains controversial, and reported postbiopsy hemorrhage rates vary widely (1%-60%). This study aimed to identify factors associated with postbiopsy hemorrhage and determine whether a selective, symptom-driven imaging strategy could safely replace routine imaging. METHODS: The data of 751 patients who underwent 753 SBBs between 1993 and 2021, all of whom received a postoperative CT within 48 hours, were retrospectively reviewed. The presence of hemorrhage of any size, the onset of new or worsening neurological symptoms within 30 days, and relevant clinical and radiographic characteristics were recorded. Neurological symptoms were categorized as early (present by the time of the first postoperative CT study) or delayed (developed after the initial CT study). Clinically significant hemorrhage was defined as bleeding on CT that prompted a change in management directly attributable to the hemorrhage. Associations between variables and hemorrhage were assessed using logistic regression and chi-square analysis. RESULTS: Blood was detected on postoperative CT imaging in 316 (42%) biopsies, most commonly at the biopsy site or along the trajectory (97%). On multivariable analysis, early postoperative symptoms (OR 3.82, 95% CI 1.34-10.9; p = 0.012), detecting blood through the biopsy needle intraoperatively (OR 2.88, 95% CI 1.37-6.06; p = 0.005), preoperative intralesional hemorrhage (OR 31.4, 95% CI 1.67-592; p = 0.021), and a platelet count of > 100 to 150 × 109/L (OR 1.7, 95% CI 1.00-2.89; p = 0.050) were associated with blood on the CT study. Patients with platelet counts ≤ 100 × 109/L conferred a fourfold increased risk that did not reach significance. New or worsening neurological symptoms were detected in 161 (21%) cases. Cases with altered mental status post-SBB were more likely to have blood on CT (69% vs 31%, p = 0.009). Four cases required intervention (2 hemorrhage evacuations, 2 ventriculostomies). The positive predictive value of postoperative CT in detecting a new or expanding hemorrhage was 17%, and the negative predictive value was 98%. Postoperative CT findings altered management in 5% of cases, predominantly in symptomatic cases. CONCLUSIONS: Routine postoperative CT after SBB may not be warranted in all patients. A symptom-driven imaging approach may reduce healthcare costs and unnecessary radiation exposure without compromising patient safety. The authors recommend selective imaging in patients with bleeding diathesis, intraoperative bleeding, existing intralesional hemorrhage, and/or new or worsening neurological symptoms. The final decision to perform a CT study is left to the treating physician's discretion.