A Comparison of Intraoperative Ultrasound and Post- Operative Mri in Paediatric Intra Axial Tumours

Background: Malignant tumours of the Central Nervous System (CNS) is the second most common paediatric malignancy, following haematological malignancy. CNS tumours depend significantly on the extent of tumour resection. In the past decade, intraoperative ultrasound (IOUS) has evolved into a widespread neuroimaging tool that offers real-time surgical guidance, and is a widely accessible imaging modality with minimal identified risk or additional operative time, and also lower economic investment. Recent studies found a strong correlation between IOUS and post operative MRI findings when evaluating extent of tumour resection in adult population suggesting that IOUS might have significant clinical implications, however not many studies involved the paediatrics population. The objective of our study was to compare correlation and reliability of the ultrasound as compared to MRI for tumour resection in paediatric population. We also evaluated IOUS as a real-time navigation tool during surgical resection of intra axial tumours in paediatric patients. Methods: This was a prospective observational study done in a Hospital Tunku Azizah, Kuala Lumpur. Patients aged less than 12 years old, admitted between 1st December 2019 to 30th November 2021 with preoperative MRI diagnosis of intra-axial brain tumour were recruited in this study. IOUS was performed intraoperatively, and post-operative MRI performed within 24-72 hours post-op. IOUS utility assessment scoring was performed intraoperatively. Results: We analysed a total of 25 paediatric patients that met the inclusion criteria. Concordance analysis between IOUS evaluation and MRI showed good agreement (kappa = 0.527). A multivariate logistic regression analysis was performed to look for any significant factors of discordance, and none of the variables were found significant for discordance. Hosmer and Lemeshow goodness of fit test was performed, and showed that our model is a good fit, with a good prediction value of 0.497. Conclusion: The use of IOUS allowed reliable intra operative imaging modality to achieve more successful gross total resection of brain tumours in paediatrics.