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Radiation Oncology |
1 From the Divisions of Radiation Oncology (J.A.K., Z.I., A.G.K., T.B., M.H.M.), Pediatric Oncology (S.G.), and Pediatric Neurosurgery (T.T.), Northwestern Memorial Hospital, 251 E Huron St, L-178, Chicago, IL 60611. From the 1999 RSNA scientific assembly. Received December 1, 1999; revision requested January 28, 2000; final revision received April 3; accepted May 11. Address correspondence to J.A.K..
PURPOSE: To determine the repositioning accuracy, patient tolerance, and clinical efficacy of stereotactic radiation therapy for brain tumors in children and adults performed with the Laitinen stereotactic localizer and head holder.
MATERIALS AND METHODS: In this retrospective analysis, stereotactic frame tolerance was assessed by recording patient discomfort or pain in the ear and nose during each treatment in 34 patients, including 21 children and 13 adults with 37 lesions treated with fractionated stereotactic radiation therapy. Radiation doses ranged from 1060 Gy at 1.04.0 Gy per fraction. Repositioning accuracy was assessed by comparing portal radiographs with setup fields on computed tomographic (CT) scout images. Clinical efficacy was assessed by analyzing posttreatment CT and magnetic resonance images.
RESULTS: The stereotactic localizer was well tolerated. The mean isocenter shifts observed after studying 305 portal radiographs were x-coordinate shift of 1.0 mm ± 0.7 (SD), y-coordinate shift of 0.8 mm ± 0.8, and z-coordinate shift of 1.7 mm ± 1.0. At a median follow-up of 16 months, local control was achieved in 18 of 22 primary and in one of eight of recurrent tumors.
CONCLUSION: The Laitinen stereotactic localizer is well tolerated with accurate reproducibility during stereotactic radiation therapy. Preliminary local control rates are consistent with those in other reports.
Index terms: Brain neoplasms, 10.31, 10.32, 10.33, 10.36 Brain neoplasms, therapeutic radiology, 10.1267, 10.1269 Computed tomography (CT), treatment planning, 10.12112, 10.1267 Magnetic resonance (MR), treatment planning, 10.121412, 10.1267 Radiations, protective and therapeutic agents and devices Stereotaxis, 10.1267