title: Permanent iodine-125 implant and external beam radiation therapy for the treatment of malignant brain tumors.
abstract: Survival data of 114 patients treated for malignant brain tumors with 125I interstitial radiation therapy at Henry Ford Hospital, Detroit, Mich. (1986-1990), are presented. The first 64 patients were treated with temporary 125I implants with a total prescribed dose of 60 Gy at a dose rate of 40 cGy/h. In order to reduce the risk of injury to the surrounding normal tissue associated with high-dose brachytherapy, a new approach was initiated using permanent implants with a lower dose rate; 50 patients were treated after surgical resection with permanent implantation of 125I seeds at a lower dose rate of 4-7 cGy/h, with a total dose of 10,000-12,000 cGy, and concurrent external radiation therapy of 5,000 cGy. The rationale of this protocol was to increase the effectiveness of the low-dose-rate implant by a concurrent 'daily' boost of external radiation, thus inhibiting the proliferation of tumor cells during the protracted low-dose radiation treatment. Survival was compared between groups with permanent and temporary implants in terms of effectiveness in tumor control as well as impact on clinical condition. Low-dose-rate implant with concurrent external radiation therapy seems to offer the best chance for long-term survival without deterioration in the clinical condition.
authors.affiliation: Department of Neurosurgery, Wayne State University, Mich.
authors.forename: L
authors.initials: L
authors.lastname: Zamorano
authors.forename: D
authors.initials: D
authors.lastname: Yakar
authors.forename: M
authors.initials: M
authors.lastname: Dujovny
authors.forename: M
authors.initials: M
authors.lastname: Sheehan
authors.forename: J
authors.initials: J
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy; D001932:Brain Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed
chemical_list: D007457:Iodine Radioisotopes