Expertise Affects Inter-Observer Agreement at Peripheral Locations within a Brain Tumor

Area of Science:

• Neuroimaging
• Radiology
• Medical image analysis

Background:

• Magnetic resonance imaging (MRI) is vital for brain tumor detection and delineation.
• Understanding clinician expertise in gross tumor volume delineation is key to improving patient outcomes.
• Limited research exists on expertise-related differences in brain tumor delineation compared to abnormality detection.

Purpose of the Study:

• To investigate expertise-related differences in brain tumor delineation using MRI scans.
• To compare the delineation performance of novices (undergraduate students) and experts (radiologists).

Main Methods:

• Participants (novices and experts) delineated brain tumors on T1 and T2 MRI scans using a tablet and stylus.
• Unlimited time was provided for free scrolling through MRI slices.
• Delineation accuracy and agreement were assessed across expertise levels and tumor locations.

Main Results:

• No significant difference was found in gross tumor volume or the number of slices delineated between novices and experts.
• Overall agreement in tumor delineation was low for both groups.
• Agreement was significantly lower at peripheral tumor locations compared to central locations.
• Experts demonstrated higher agreement at peripheral slices than novices.
• The order of slice inspection was influenced by the brain image set.

Conclusions:

• Expertise level did not reliably affect overall brain tumor volume or slice delineation.
• Tumor delineation agreement is challenging, particularly at peripheral tumor margins.
• Experts show an advantage in delineating peripheral tumor areas, indicating potential areas for targeted training.
• Findings have implications for early career radiologist training and current hospital practices in brain tumor management.