title: Three-year recurrence-free survival in a patient with recurrent medulloblastoma after resection, high-dose chemotherapy, and intrathecal Yttrium-90-labeled DOTA0-D-Phe1-Tyr3-octreotide radiopeptide brachytherapy.
abstract: BACKGROUND
  Most medulloblastomas express high levels of somatostatin type 2 receptors (sst2). DOTA0-D-Phe1-Tyr3-octreotide (DOTATOC) specifically binds sst2 in the low nanomolar range. The cytotoxic effect is mediated by the chelated, beta-emitting, metallic radionuclide Yttrium 90 (90Y). The authors applied this innovative treatment option in a boy age 8 years who presented with a recurrent medulloblastoma of the cauda equina: a prognostically poor condition. Targeted radiotherapy was administered to treat minimal sst2-expressing tumor remnants, which persisted despite conventional and high-dose chemotherapy and intercurrent resection of the lesion.
  
  
  METHODS
  A medulloblastoma arising from the floor of the fourth ventricle had been removed surgically; then, the patient was treated with standard adjuvant chemotherapy and craniospinal irradiation according to the prospective HIT '91 protocol. Complete remission was achieved for 20 months, when a drop metastasis of the cauda equina manifested with sensorimotor lumbosacral deficits and urinary incontinence. After four cycles of neoadjuvant chemotherapy (which consisted of combined ifosfamide, carboplatinum and etoposide), two cycles of high-dose chemotherapy and autologous stem cell transplantation were performed; in between, the responding residual tumor within the lumbosacral nerve fibers was microscopically removed. Thereafter, an Indium-111-DOTATOC test injection indicated sst2-expressing tumor remnants within the cauda equina. Consequently, 4 cycles of [90Y]-DOTATOC (4x562.5 megabecquerels) were injected directly into the cerebrospinal fluid in monthly intervals.
  
  
  RESULTS
  The consolidating intrathecal brachytherapy using [90Y]-DOTATOC was tolerated well. A complete remission was achieved for a 3-year period. The only remaining deficit was urinary incontinence.
  
  
  CONCLUSIONS
  Intrathecal administration of targeted radiopeptide brachytherapy in combination with conventional and high-dose chemotherapy and surgical removal represents a promising new option to treat recurrent medulloblastoma and should be explored further.
authors.affiliation: Department of Oncology/Hematology, University Children's Hospital Basel, Basel, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Beutler
authors.forename: Pierino
authors.initials: P
authors.lastname: Avoledo
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Reubi
authors.forename: Helmut R
authors.initials: HR
authors.lastname: Mäcke
authors.forename: Jan
authors.initials: J
authors.lastname: Müller-Brand
authors.forename: Adrian
authors.initials: A
authors.lastname: Merlo
authors.forename: Thomas
authors.initials: T
authors.lastname: Kühne
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D001918:Brachytherapy; D002420:Cauda Equina / Q000378:metabolism / Q000473:pathology*; D002528:Cerebellar Neoplasms / Q000628:therapy*; D002648:Child; D018572:Disease-Free Survival; D006801:Humans; D007150:Immunohistochemistry; D007278:Injections, Spinal; D008297:Male; D008527:Medulloblastoma / Q000378:metabolism / Q000556:secondary* / Q000628:therapy*; D015282:Octreotide / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; D015282:Octreotide; C106246:Edotreotide