Pediatric Neuroblastoma — Post-MIBG Therapy

131-I-MIBG (iodine-131-metaiodobenzylguanidine) is a targeted radiotherapeutic agent taken up by the norepinephrine transporter on neuroblastoma cells, used in relapsed or refractory high-risk disease, often combined with chemotherapy or autologous stem cell rescue.

Acute post-therapy management requires strict radiation safety precautions, isolation in a lead-shielded room until activity drops below regulatory limits, careful waste handling, and parental education on contact restrictions.

Hematologic toxicity is the dose-limiting effect; thrombocytopenia and neutropenia typically nadir 4 to 6 weeks after therapy and may require platelet transfusions, granulocyte colony stimulating factor or autologous hematopoietic stem cell infusion in tandem schedules.

Endocrine effects include thyroid dysfunction (hypothyroidism in up to 60 percent of long-term survivors despite blockade with potassium iodide) requiring lifelong thyroid surveillance, gonadal toxicity and hypothalamic-pituitary axis effects.

Disease response is assessed by post-therapy 123-I-MIBG scintigraphy (or 124-I MIBG PET), urinary catecholamines, MRI of primary site and bone marrow biopsy at standardized intervals to guide subsequent immunotherapy, surgery, radiotherapy or palliative care decisions.