<qa>  What is the confirmation of viable tumor on CT scan, MRI, or MIBG scan?- Patients in first response i.e., patients with persistent tumor at end of frontline therapy, but who have never had disease relapse or progression must have histological or morphological by bone marrow confirmation of viable tumor on CT scan, MRI, or MIBG scan after completion of myeloablative therapy for strata I and II 