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.

High Pressure Balloon Dilatation of Primary Obstructive Megaureter in Children: A Multicenter Study.

Aim of the Study: We described the initial experience of four referral centers in the treatment of primary obstructive megaureter (POM) in children, by high-pressure balloon dilatation (HPBD) of the ureterovesical junction with double JJ stenting. We managed a retrospective multicenter study to assess its effectiveness in long-term. Methods: We reviewed the medical records of all children who underwent HPBD for POM that require surgical treatment from May 2012 to December 2017 in four different institutions. The primary outcome measured was ureterohydronephrosis (UHN) and its degree of improvement after the procedure. Secondary outcomes were postoperative complications and resolution of preoperative symptomatology. Main Results: Forty-two ureters underwent HPBD for POM in 33 children, with a median age of 14.7 months - (range: 3 months -15 years). Ureterohydronephrosis improves in 86% of ureters after one endoscopic treatment. Three cases required a second HPBD. Four patients required surgical treatment for worsening of UHN after endoscopic treatment. The post-operative complication rate was 50% (21 ureters). In 13 cases (61%), they were related to double J stent. The median follow-up was 24 months (2 months -5 years) and all patients were symptom-free. Conclusion: We reported the first multicenter study and the largest series of children treated with HPBD, with an overall success rate of 92%. Endoscopic treatment can be a definitive treatment of POM since it avoided reimplantation in 90% of cases. Complications are mainly due to double J stent.