title: Intrathecal therapy with 198Au-colloid for meningosis prophylaxis.
abstract: Telecobalt irradiation in combination with intrathecal (IT) methotrexate has been replaced by IT 198Au-colloid and methotrexate for meningosis prophylaxis in leukemia. Seventy-seven children received 56-200 MBq 198Au-colloid. The distribution was measured with a scintillation camera having a data processing facility. The radiopharmaceutical is adsorbed at the surface of the spaces with cerebrospinal fluid (CSF) 10-20 h after application. The normal retention of the administered radioactivity in the intracranial subarachnoid space (ISS) and in the spinal subarachnoid space (SSS) were 52 +/- 10% and 26 +/- 9%, respectively. An impairment of the normal distribution was observed after IT methotrexate and also postinjection CSF leakage. The calculated radiation absorbed doses in the cerebral and spinal meninges at a depth of 0.01 cm, i.e. the thickness of the pia, were 45 +/- 17 mGy and 189 +/- 91 mGy, respectively, for 1 MBq administered 198Au-colloid. The dosimetry shows that an effective radiation absorbed dose of 18 Gy can be delivered to the cerebral meninges by the application of 400 MBq 198Au-colloid.
mesh_terms: D000208:Acute Disease; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D004285:Dogs; D004307:Dose-Response Relationship, Radiation; D006048:Gold Colloid, Radioactive / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D007278:Injections, Spinal; D007938:Leukemia / Q000532:radiotherapy*; D008577:Meningeal Neoplasms / Q000517:prevention & control*; D008578:Meninges / Q000528:radiation effects*; D008727:Methotrexate / Q000008:administration & dosage / Q000627:therapeutic use; D011817:Rabbits; D011879:Radiotherapy Dosage
chemical_list: D006048:Gold Colloid, Radioactive; D008727:Methotrexate