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Time window for postoperative reactive enhancement after resection of brain tumors: less than 72 hours
Stephanie Lescher1, Sonja Schniewindt, Alina Jurcoane
1Institute of Neuroradiology and.
Object:
Early postoperative MRI within 72 hours after brain tumor surgery is commonly used to assess residual contrast-enhancing tumor. The 72-hour window is commonly accepted because previous 1.5-T MRI studies have not found confounding postoperative reactive contrast enhancement in this time frame. The sensitivity to detect contrast enhancement increases with the field strengths. Therefore, the authors aimed to assess whether the 72-hour window is also appropriate for the MRI scanner with a field strength of 3 T.
Methods:
The authors retrospectively analyzed findings on early postsurgical MR images acquired in 46 patients treated for high-grade gliomas. They performed 3-T MRI within 7 days before surgery and within 72 hours thereafter. The appearance of enhancement was categorized as postoperative reactive enhancement or tumoral enhancement by comparison with the pattern and location of presurgical enhancing tumor.
Results:
Postoperative reactive enhancement was present in 15 patients (32.6%). This enhancement, not seen on presurgical MRI, had a marginal or leptomeningeal/dural pattern. In 13 patients (28.3%) postsurgical enhancement was found within the first 72 postoperative hours, with the earliest seen 22:57 hours after surgery. Subsequent MR scans in patients with postoperative reactive enhancement did not reveal tumor recurrence in these regions.
Conclusions:
Postoperative reactive enhancement earlier than 72 hours after brain tumor surgery can be expected in about one-third of the cases in which a 3-T scanner is used. This might be due to the higher enhancement-to-brain contrast at higher field strengths. Therefore, the time window of 72 hours does not prevent reactive enhancement, which, however, can be recognized as such comparing it with presurgical enhancing tumor.
Insights
Early postoperative MRI using 3-T scanners can show reactive enhancement within 72 hours in about one-third of brain tumor patients. This enhancement is distinct from tumor recurrence and can be identified by comparing with presurgical scans.
Area of Science:
- Radiology
- Neuro-oncology
- Medical Imaging
Background:
- Postoperative MRI within 72 hours is standard for assessing residual contrast-enhancing tumor after brain surgery.
- Previous 1.5-T MRI studies established this window, finding no confounding reactive enhancement.
- Higher field strength MRI scanners, like 3-T, may increase sensitivity to contrast enhancement.
Purpose of the Study:
- To evaluate if the 72-hour postoperative MRI window is appropriate for 3-T scanners.
- To determine the incidence and characteristics of early postoperative contrast enhancement using 3-T MRI.
Main Methods:
- Retrospective analysis of 46 high-grade glioma patients.
- Comparison of 3-T MRI scans acquired within 7 days pre-surgery and within 72 hours post-surgery.
- Categorization of enhancement as reactive or tumoral based on presurgical patterns.
Main Results:
- Postoperative reactive enhancement occurred in 32.6% of patients.
- This enhancement, absent pre-surgery, typically presented with a marginal or leptomeningeal/dural pattern.
- Early enhancement within 72 hours was observed in 28.3% of cases, with the earliest at 22:57 hours post-surgery.
Conclusions:
- About one-third of patients may exhibit postoperative reactive enhancement within 72 hours when using 3-T MRI.
- This phenomenon is likely due to increased contrast-to-brain enhancement at higher field strengths.
- The 72-hour window remains viable, as reactive enhancement can be distinguished from tumor recurrence by comparison with presurgical imaging.
