Image-guided stereotactic body radiation therapy using a low-Z target imaging beam line and a high dose rate unflattened beam
Extension of hypofractionated stereotactic radiation therapy to extracranial sites is now possible due to the technological improvements in image guidance and immobilization devices. Treatment of non-small cell lung cancer using stereotactic body radiotherapy (SBRT) in particular shows very promising results. We will present our institution’s initial experience of SBRT treatment using a megavoltage conebeam computed tomography (MV-CBCT) imaging beam line (IBL) and a new enhanced stereotactic treatment (EST) mode. The IBL combines the effects of a low-Z carbon target, lower accelerating potential and removal of the flattening filter to lower the average photon energy, thereby increasing the image quality and lowering the imaging dose. During treatment delivery in EST mode, the flattening filter is removed, and monitoring equipment is modified, in order to increase the dose rate and reduce the treatment time, therefore decreasing the risk of patient movement.
KeywordsImaging immobilization SBRT
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