Abstract

Objective: To evaluate the treatment outcomes of patients with LR and IR NB at the Vietnam National Children's Hospital (VNCH) between 2021 and 2024 by SIOPEN protocol.

Methods: This retrospective, descriptive study included 75 patients with LR or IR NB who were diagnosed and treated according to the SIOPEN protocol at VNCH between January 2021 and December 2024, followed to 30 June 2026.

Results: the median age at diagnosis was 10.2 months. Most patients (92%) were younger than 5 years of age, while 8% were greater than and equal to 5 years. Overall, 43 patients (57.3%) were stratified  as LR. Among patients in the LR group, 11 patients (25.6%) were managed with observation alone, whereas 32 patients (74.4%) required chemotherapy or combined with surgery. Most low-risk patients received only 2–4 cycles of chemotherapy, and only 12% required more than four cycles. In the 32 patients with IR group, 18 of them required more than four cycles of chemotherapy, and half receiving greater than or equal to six cycles. The mean follow-up duration was 39.1 ± 15.4 months. The estimated 5-year overall survival (OS) and event-free survival (EFS) rates for the entire cohort were 97.3% and 89.6%, respectively. The 5-year EFS rates were 95.4% for the LR group and 82.1% for the IR group (p = 0.116); 5-year EFS rates of patients with favorable and unfavorable histology were 92.5% and 81.4%, respectively (p=0,411). There are also no significant differences in 5-year EFS were observed between or among subgroups stratified by urinary VMA and HVA, or serum LDH levels.

Conclusions: Children with LR and IR neuroblastoma achieved excellent treatment outcomes with the SIOPEN protocol.