title: Results of re-irradiation of primary intracranial neoplasms with three-dimensional conformal therapy.
abstract: We evaluated the potential of three-dimensional conformal therapy for re-irradiation of selected intracranial neoplasms and reviewed the retreatment of 20 patients at the University of Michigan between May 1988 and August 1991. All patients had previously undergone a full course of external beam radiotherapy (RT) to a median dose of 5,940 cGy (range 5,100-6,500 cGy), including five whole brain treatments. All recurrences were unsuitable for brachytherapy or radiosurgery. Various histologies were retreated, including 14 high-grade gliomas. Median time to re-irradiation was 38 months (range 9 months to 19 years, 6 months). RT was delivered with complex plans designed using fully integrated computed tomography/magnetic resonance imaging (CT/ MRI) tumor volume information, and regions of previous parenchymal treatment were avoided if possible. Composite (initial+retreatment) dose-volume histograms (DVH) of dose to nontarget brain allowed comparison of alternative plans to select beam orientations which minimized normal brain irradiation. Mean target dose of re-irradiation was 3,600 cGy (range 3,060-5,940 cGy). Total cumulative dose ranged from 8,060 to 11,940 cGy. Median survival was 9 months, and 1-year actuarial survival was 26%. After retreatment, 8 of 12 patients (67%) had steroid dose decrement and neurologic improvement at 4-48 months (median duration 14 months). Radiographic regression or stabilization of disease was noted in 11 of 16 patients (68%). Re-irradiation with highly conformal three-dimensional planning provides frequent clinical improvement with acceptable morbidity and should be considered in selected patients with recurrent intracranial neoplasms.
authors.affiliation: Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, USA.
authors.forename: H K
authors.initials: HK
authors.lastname: Kim
authors.forename: A F
authors.initials: AF
authors.lastname: Thornton
authors.forename: H S
authors.initials: HS
authors.lastname: Greenberg
authors.forename: M A
authors.initials: MA
authors.lastname: Page
authors.forename: L
authors.initials: L
authors.lastname: Junck
authors.forename: H M
authors.initials: HM
authors.lastname: Sandler
mesh_terms: D000206:Actuarial Analysis; D000328:Adult; D001254:Astrocytoma / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D001921:Brain / Q000528:radiation effects; D017024:Chemotherapy, Adjuvant; D016371:Cranial Irradiation / Q000379:methods*; D005500:Follow-Up Studies; D005909:Glioblastoma / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D005910:Glioma / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy; D009460:Neurologic Examination; D011879:Radiotherapy Dosage; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D011882:Radiotherapy, High-Energy; D012074:Remission Induction; D019233:Retreatment; D013256:Steroids / Q000008:administration & dosage / Q000627:therapeutic use; D015173:Supratentorial Neoplasms / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D013256:Steroids