DISEASE CHARACTERISTICS: Histologically confirmed, Stage IV neuroblastoma in second or subsequent complete remission, defined by the complete disappearance of all evidence of tumor on the following: Physical examination Second-look surgery Bone scan Bone marrow aspiration and biopsy Chest x-ray CT MIBG Urinary catecholamines If marrow is infiltrated by tumor, complete elimination of tumor cells from the marrow compartment must be demonstrated by histology and immunofluorescence (based on simultaneous bone marrow aspiration and biopsy samples from at least 4 separate sites)