Revisiting the role of radiotherapy in the treatment of neuroblastoma 4S: 30 years of institutional experience and systematic review.

Background And Purpose: Neuroblastoma 4S is a rare subtype of metastatic neuroblastoma found in children younger than 12 months, characterized by liver, skin, or bone marrow metastases. While the prognosis for patients is generally favorable, rapid progression of liver metastases can lead to life-threatening organ insufficiency. In such cases, immediate treatment with chemotherapy or radiotherapy is necessary. Given the recent decline in radiotherapy utilization, this study aims to reassess its role, evaluating its effectiveness and toxicity.

Materials And Methods: We conducted a systematic review and an institutional retrospective analysis to assess the use of radiotherapy for hepatomegaly in patients with neuroblastoma 4S. The study included data from 164 patients from the literature and 16 patients from our institutional cohort. We extracted and analyzed data on short- and long-term outcomes, as well as reports of radiotherapy-induced toxicity.

Results: Our institutional data showed that 81 % of patients responded to low-dose radiotherapy administered at a median dose of 450 cGy in three fractions, resulting in liver shrinkage and symptom resolution. Based on the systematic review, 1-year survival rate was 80 %, while 5-year survival rate was 75 %. No serious toxicity was observed with the current low-dose radiotherapy; however, one case of induced secondary malignancy was reported.

Conclusion: Radiation therapy is an effective treatment modality for hepatomegaly in patients with neuroblastoma 4S, with a success rate of about 80 %. Despite being administered to infants, a low dose of 450-600 cGy does not result in toxicity related to the kidneys, liver, or posture defects.