Unresectable thoracic neuroblastic tumors: Changes in image-defined risk factors after chemotherapy and impact on surgical management.

Purpose Neuroblastoma management in children is multimodal and depends on multiple factors, including the possibility of complete surgical resection. Image-defined risk factors (IDRFs) are used to assess the feasibility of primary surgery. We studied the changes in IDRFs after neoadjuvant chemotherapy for thoracic neurogenic tumors. Methods We performed a multicenter review of 27 patients presenting with unresectable thoracic neurogenic tumors. Patients received neoadjuvant chemotherapy, according to their risk group. IDRF at diagnosis and before surgery were retrospectively analyzed by a radiologist and a surgeon, blind to the initial assessment. Surgical and oncologic outcomes were reviewed. Results None of the patients presented MYCN amplification, and 78 IDRFs were identified at diagnosis. Vascular IDRFs were the most frequent, with 28 vascular IDRFs detected in 18 patients, 22 of which disappeared after chemotherapy. Reductions of tumor volume were associated with a regression of IDRFs. Patients undergoing minimally invasive surgery had smaller tumor volumes than those undergoing open surgery, and no vascular IDRF. Two patients received two additional courses of chemotherapy to reduce tumor volume sufficiently for surgery. One patient with ganglioneuroblastoma underwent early surgery due to a lack of response to initial chemotherapy. Conclusion Tumor volume reduction with neoadjuvant chemotherapy eliminates most IDRF in thoracic neurogenic tumors. Vascular IDRF are rapidly resolved at this site, making surgical resection and minimally invasive surgery possible.