In the International Society of Paediatric Oncology Europe Neuroblastoma (SIOPEN) HR-NBL-1 protocol, only patients with metastatic complete response (CR) or partial response (PR) with ≤ three abnormal skeletal areas on iodine 123-metaiodobenzylguanidine ([<sup>123</sup>I]mIBG) scintigraphy and no bone marrow disease proceed to high dose therapy (HDT).