Differentiation between high and low grade tumours in paediatric patients by using apparent diffusion coefficients

Area of Science:

• Neuro-oncology
• Radiology
• Paediatric Medicine

Background:

• Distinguishing between low-grade and high-grade paediatric brain tumours pre-operatively is crucial for treatment planning.
• Conventional MRI findings can sometimes be ambiguous in differentiating tumour grades in children.

Purpose of the Study:

• To evaluate the effectiveness of pre-operative apparent diffusion coefficient (ADC) values in distinguishing low-grade from high-grade paediatric brain tumours.
• To establish potential cut-off ADC values for tumour grading in paediatric patients.

Main Methods:

• Retrospective analysis of ADC values from 36 paediatric brain tumours.
• Comparison of minimum and mean ADC values between confirmed low-grade and high-grade tumour groups.
• Evaluation of specific ADC cut-off values for diagnostic differentiation.

Main Results:

• Established cut-off values for differentiating tumour grades: 0.7 × 10⁻³ mm²/s (minimum ADC) and 1.0 × 10⁻³ mm²/s (average ADC).
• Significantly lower ADC values were observed in most high-grade paediatric brain tumours compared to low-grade tumours.
• One high-grade infratentorial ependymoma was an exception, showing higher ADC values than typical for its grade.

Conclusions:

• Pre-operative ADC values, when combined with conventional MRI, can enhance the accuracy of differentiating paediatric brain tumour grades.
• Defined ADC cut-off values provide a valuable tool for discerning low-grade from high-grade paediatric brain tumours.
• Potential overlap in ADC values between certain tumour types necessitates careful interpretation in clinical practice.