Impact of Neoadjuvant Chemotherapy on Image-Defined Risk Factors in High-Risk Neuroblastoma

Purpose Image-defined risk factors (IDRFs) are associated with surgical risks in neuroblastoma. We sought to evaluate the impact of neoadjuvant therapy on IDRFs and associated ability to achieve gross total resection (GTR) of locoregional disease in patients with high-risk neuroblastoma. Methods We retrospectively reviewed charts of patients treated on four consecutive high-risk neuroblastoma protocols over a 20-year period at a single institution. The number of IDRFs at diagnosis and just prior to surgery, and the percent decrease of tumor volume from just prior to surgery to the end of induction were determined. Results Eighty-eight patients were included. There were 438 IDRFs (average 5.0 ± 3.1 per patient) at diagnosis and 198 (average 2.3 ± 1.9 per patient) after neoadjuvant chemotherapy ( p < 0.01). A reduction in IDRFs was seen in 81.8% of patients with average decrease of 2.9 ± 2.5 per patient. The average percent reduction in tumor volume was 89.8 ± 18.9% and correlated with the number of IDRFs present after chemotherapy ( p < 0.01). Three or fewer IDRFs prior to surgery was associated with the highest odds ratio for > 90% GTR at 9.33 [95% confidence interval 3.14–31.5]. Conclusion Neoadjuvant chemotherapy reduced the number of IDRFs in the majority of patients with high-risk neuroblastoma. The number of IDRFs present after neoadjuvant therapy correlated with the extent of resection.