title: Targeted radiotherapy with submyeloablative doses of 131I-MIBG is effective for disease palliation in highly refractory neuroblastoma.
abstract: OBJECTIVE
  Treatment of refractory neuroblastoma remains a significant clinical problem. Targeted radiotherapy with 131I-MIBG has demonstrated antitumor activity in heavily pretreated neuroblastoma patients with recurrent disease. Response rates may be correlated with total radionuclide dose per kilogram body weight delivered, but higher dose levels are associated with protracted grade 4 hematologic toxicity. The optimal method for using single-agent 131I-MIBG for patients with relapsed high-risk neuroblastoma has not been defined. This study was designed to retrospectively determine the clinical response to 131I-MIBG therapy at submyeloablative doses in patients with refractory neuroblastoma and to describe the toxicities.
  
  
  METHODS
  A retrospective chart review of 20 patients with neuroblastoma treated with 131I-MIBG at the Children's Hospital of Philadelphia from 1988 to 2000 was performed. Demographic data, 131I-MIBG dose delivered, toxicities, and clinical responses were reviewed.
  
  
  RESULTS
  A median dose of 9.5 mCi/kg of 131I-MIBG was delivered in 32 courses to 20 patients. Three patients were treated in first complete response, and the remaining 17 patients for residual and/or progressive disease. The objective response rate to the first therapy was 31%, and the remaining patients achieved disease stabilization. In addition, 9 of 11 patients with pain at study entry had significant improvement. Disease response was not correlated with 131I-MIBG dose delivered. No unanticipated toxicities were observed.
  
  
  CONCLUSIONS
  Submyeloablative-dose 131I-MIBG is an effective and relatively nontoxic method for neuroblastoma disease palliation. Most patients show subjective improvement in pain and/or performance status. Increased availability and experience with 131I-MIBG therapy would benefit a large number of children with end-stage neuroblastoma and no realistic hope for cure.
authors.affiliation: Division of Oncology, Children's Hospital of Philadelphia, PA 19104-4318, USA.
authors.forename: Tammy I
authors.initials: TI
authors.lastname: Kang
authors.forename: Patricia
authors.initials: P
authors.lastname: Brophy
authors.forename: Mark
authors.initials: M
authors.lastname: Hickeson
authors.forename: Sydney
authors.initials: S
authors.lastname: Heyman
authors.forename: Audrey E
authors.initials: AE
authors.lastname: Evans
authors.forename: Martin
authors.initials: M
authors.lastname: Charron
authors.forename: John M
authors.initials: JM
authors.lastname: Maris
mesh_terms: D019797:3-Iodobenzylguanidine / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D000293:Adolescent; D001792:Blood Platelets / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007457:Iodine Radioisotopes; D008297:Male; D009367:Neoplasm Staging; D009447:Neuroblastoma / Q000150:complications / Q000532:radiotherapy*; D010146:Pain / Q000150:complications / Q000188:drug therapy / Q000532:radiotherapy; D010166:Palliative Care / Q000379:methods*; D019275:Radiopharmaceuticals / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use*; D012189:Retrospective Studies
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine