Intensity-modulated radiation therapy (IMRT) for XXXX .

@entity1 @entity137 @entity146 @entity5 @entity1653 @entity230 @entity10 @entity204 @entity528
PURPOSE: To assess the safety and efficacy of intensity-modulated radiation therapy (IMRT) in the treatment of @entity1653 . METHODS AND MATERIALS: Forty @entity1 with @entity1653 (excluding optic nerve @entity1653 ) were treated using IMRT with the NOMOS Peacock system between 1994 and 1999. Twenty-five @entity1 received IMRT after surgery either as adjuvant therapy for incomplete resection or for recurrence, and 15 @entity1 received definitive IMRT after presumptive diagnosis based on imaging. Thirty-two @entity1 had skull base lesions, and 8 had nonskull base lesions. The prescribed dose ranged from 40 to 56 Gy (median 50.4 Gy) at 1.71 to 2 Gy per fraction, and the volume of the primary target ranged from 1.55 to 324.57 cc (median 20.22 cc). The mean dose to the target ranged from 44 to 60 Gy (median 53 Gy). Follow-up ranged from 6 to 71 months (median 30 months). Acute and chronic @entity137 were assessed using Radiation Therapy Oncology Group (RTOG) morbidity criteria and @entity5 response was assessed by @entity1 report, examination, and imaging. Overall survival, progression-free survival, and local control were calculated using the Kaplan-Meier method. RESULTS: Cumulative 5-year local control, progression-free survival, and overall survival were 93%, 88%, and 89%, respectively. Two @entity1 progressed after IMRT, one locally and one distantly. Each was treated with IMRT after multiple recurrences of @entity1653 over many years. Both were found to have @entity5 at the time of relapse after IMRT, and it is likely their @entity5 had already undergone malignant change by the time IMRT was given. Defined normal structures generally received a significantly lower dose than the target. The most common acute central nervous system (CNS) @entity137 was mild @entity10 , usually relieved with @entity230 . One @entity1 experienced RTOG Grade 3 acute CNS @entity137 , and 2 experienced Grade 3 or higher late CNS @entity137 , with one possible treatment-related @entity204 . No @entity137 was observed with mean doses to the optic nerve/chiasm up to 47 Gy and maximum doses up to 55 Gy. CONCLUSION: IMRT is a promising new technology that is safe and efficacious in the primary and adjuvant treatment of @entity1653 . A history of @entity146 may indicate @entity528 and predict a poorer outcome. @entity137 data are encouraging, but the potential for serious side effects exists, as demonstrated by one possible treatment-related @entity204 . Larger cohort and longer follow-up are needed to better define efficacy and late @entity137 of IMRT.
