Frameless Fractionated Stereotactic Radiotherapy Using Linear Accelerator in Large Brain Tumors

ABSTRACT

OBJECTIVE: The goals of this study are to introduce the method of fractionated stereotactic radiotherapy (FSRT), to make treatment plans and to evaluate the role of frameless FSRT in large brain tumors. METHODS: Between August 1997 and December 2000, FSRT was performed in 47 patients with brain lesion. Eighteen patients had brain tumor larger than 3cm. We used 'Point Reference System' of Northwest Medical Physics Center. Three gold markers were fixated at a given place instead of sticking the frame in the head. We used multiple-arc FSRT for round tumor and conformal FSRT for irregular tumor. RESULTS: There was no acute toxicity, except for transient headache and dizziness in two patients. Patients did not need to be hospitalized, and also did not suffer from being invasive with frames. In the radiological response of tumor volume, 2(11.1%) showed complete remission. 8(44.5%) were reduced. 4(22.2%) showed no change. 4(22.2%) were not followed up. In the clinical response of symptoms, 9(50%) were improved, 7(38.9%) were continued, and 2(11.1%) were aggravated. There were limitations that the clinical results of each patient were varied in diagnosis and underlying disease. CONCLUSION: We can apply FSRT for brain tumor larger than 3cm safely and effectively, regardless of shape irregularity and minimize the injury of normal brain tissue.