EARLY postoperative MRI demonstrated diagnostic accuracies of 95% and 90% for two independent readers assessing residual disease after neuroblastoma surgery. This may help inform postoperative treatment decisions.
The findings suggest that early postoperative MRI can provide a reliable baseline for follow-up imaging while identifying residual tumour deposits that may not be apparent during surgery.
Neuroblastoma is the most common solid extracranial malignancy in children, and approximately 50% of patients present with high-risk disease at diagnosis. In these cases, accurate identification of residual disease after surgery is important because it can influence radiotherapy planning, further surgical intervention and systemic treatment strategies.
Why Early Postoperative MRI Could Fill an Imaging Gap
Assessment of residual disease remains challenging following neuroblastoma resection. In abdominal midline tumours, surgeons may intentionally leave macroscopic tumour tissue behind to avoid serious complications or functional impairment.
Current imaging follow-up is typically performed around three months after surgery. However, at that stage, postoperative scarring, reactive tissue changes and possible early recurrence can make interpretation difficult. As a result, there has been growing interest in incorporating early postoperative MRI into postoperative assessment, similar to approaches already used in brain tumours.
Early Postoperative MRI Shows High Diagnostic Accuracy
The retrospective single-centre study included 39 patients with histologically confirmed neuroblastic tumours who underwent surgical resection and early postoperative MRI. The median age at surgery was 46 months, and most patients had stage 4 disease according to the International Neuroblastoma Staging System. All patients had at least one image-defined risk factor, indicating intermediate- or high-risk disease.
Preoperative MRI was performed a median of 14 days before surgery, while early postoperative MRI was performed a mean of 8 ± 5 days after surgery. Two independent paediatric radiologists, blinded to all clinical information, surgical reports and outcomes, evaluated the scans.
Residual disease was ultimately confirmed in 14 patients using a hierarchical multimodal reference standard incorporating surgical reports, expert consensus and follow-up imaging with a median follow-up of 33 months.
Diagnostic accuracy for early postoperative MRI was 95% for one reader and 90% for the second. Inter-reader agreement was substantial, with a Cohen’s kappa value of 0.76.
Small Residual Lesions Identified Beyond Surgical Assessment
Of the 14 confirmed residual lesions, five had been documented by surgeons and had a median MRI volume of 8 ml. The remaining nine lesions had not been recorded intraoperatively and were considerably smaller, with a median volume of 1 ml.
The findings suggest that early postoperative MRI may offer added value beyond surgical inspection, particularly for identifying small residual lesions that were not documented during surgery.
Implications for Neuroblastoma Management
The investigators reported that early postoperative MRI led to clinically relevant management changes in selected cases, including re-operation and refinement of subsequent treatment strategies. In addition, early postoperative MRI provided a robust baseline for future imaging assessments.
The authors cautioned that the study was limited by its small sample size, retrospective design and single-centre setting. Selection bias also cannot be excluded because many patients without early postoperative MRI were not eligible for inclusion.
Despite these limitations, the findings support early postoperative MRI as a complementary component of postoperative evaluation in specialised centres. Further research is needed to determine its effect on patient outcomes.
Reference
Chaika M et al. Inter-reader agreement and diagnostic accuracy of early postoperative magnetic resonance imaging for detecting macroscopic residual disease in neuroblastic tumors. Pediatr Radiol. 2026;DOI:10.1007/s00247-026-06672-5.
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