Should Renal Vessel Contact Be Considered an Image-Defined Risk Factor in Abdominal Neuroblastoma?

Renal vessel contact is classified as an image-defined risk factor (IDRF) in neuroblastoma, influencing staging and treatment. We evaluated its impact on renal outcomes and risk classification.

We retrospectively reviewed children with abdominal neuroblastoma and radiologic renal vessel contact treated at Beijing Children's Hospital between January 2018 and June 2023. Staging and risk stratification were assessed using the 2009 International Neuroblastoma Risk Group and 2021 revised Children's Oncology Group classification systems; reclassification analyses were performed retrospectively and did not reflect treatment decisions at diagnosis.

Fifty-nine patients were included; 44 (74.6%) had renal vessel contact as the sole IDRF and 15 (25.4%) had additional IDRFs. Excluding renal vessel contact as an IDRF reclassified 18 patients. Under the 2009 system, 3 patients were reclassified from intermediate risk to very low risk and 15 from low risk to very low risk; under the 2021 system, 15 were reclassified from intermediate risk to low risk and 3 from high risk to low risk. Transient renal ischemia occurred in 1 patient and resolved intraoperatively. No patient underwent nephrectomy, and no renal atrophy was identified at a median follow-up of 43 months. Three-year overall survival, event-free survival, and cumulative incidence of local progression were 89.1%, 86.0%, and 5.4%, respectively. No oncologic events occurred among the 18 reclassified patients.

Limited renal vessel contact was not associated with kidney loss but substantially altered staging and risk classification. These findings support reconsideration of renal vessel contact alone as an IDRF in abdominal neuroblastoma.