title: Treatment of recurrent malignant gliomas with stereotactic intensity modulated radiation therapy.
abstract: Malignant gliomas are usually refractory to aggressive combined-modality therapy, and the incidence of recurrence and death after treatment is very high. State-of-the-art techniques such as stereotactic intensity-modulated radiation therapy (IMRT) are now available to deliver a high dose of radiation to the tumor with relative preservation of surrounding tissues to achieve optimal tumor coverage with minimal toxicity. We report 10 patients (median age 48 years) with recurrent malignant gliomas that were treated with stereotactic directed IMRT. Initial tumor histologies included one low grade glioma (upgraded to anaplastic astrocytoma at recurrence), four anaplastic astrocytomas, and four glioblastomas multiforme. One patient was originally presumed to have a brain metastasis secondary to renal cell carcinoma but was pathologically confirmed as having glioblastoma multiforme at the time of recurrence. Before recurrence, all patients had been treated with external beam radiation therapy (median 59.7 Gy). All recurrences were confirmed by a subtotal resection (5/10) or by imaging (5/10). The median Karnofsky performance score at the time of IMRT was 80. The median tumor volume was 34.69 cm. Treatment was delivered on a 10-MV linear accelerator with a mini-multileaf collimator, MIMiC, and planned with Peacock/Corvus software. Radiation was delivered in daily fractions of 5 Gy, to a total median dose of 30 Gy at the 71% to 93% median isodose line. Median overall survival time was 10.1 months from the date of stereotactic treatment, with 1- and 2-year survival rates of 50% and 33.3%, respectively. Fractionated stereotactic intensity modulated radiation therapy is a novel technique used in the treatment of recurrent malignant gliomas, which produces results comparable to other currently used stereotactic techniques.
authors.affiliation: Department of Radiation Oncology, University of Connecticut Health Center, Farmington, Connecticut 06030-2930, USA.
authors.forename: George
authors.initials: G
authors.lastname: Voynov
authors.forename: Seth
authors.initials: S
authors.lastname: Kaufman
authors.forename: Theodore
authors.initials: T
authors.lastname: Hong
authors.forename: Arthur
authors.initials: A
authors.lastname: Pinkerton
authors.forename: Richard
authors.initials: R
authors.lastname: Simon
authors.forename: Robert
authors.initials: R
authors.lastname: Dowsett
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016543:Central Nervous System Neoplasms / Q000532:radiotherapy*; D016371:Cranial Irradiation / Q000379:methods*; D003907:Dexamethasone / Q000627:therapeutic use; D005260:Female; D005910:Glioma / Q000532:radiotherapy*; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016879:Salvage Therapy; D013238:Stereotaxic Techniques; D016019:Survival Analysis
chemical_list: D005938:Glucocorticoids; D003907:Dexamethasone