Feasibility of external beam radiation therapy to deep‐seated targets with kilovoltage x‐rays

Abstract

This study demonstrated that conformal treatments of deep-seated targets were achievable with kilovoltage x-rays with dose distributions comparable to MV beams. However, due to the larger volumes irradiated to clinically tolerated low doses, KVAT x-ray source usage for deep-seated lesions will be further evaluated to determine optimal target size.

Monte Carlo simulations of a kilovoltage external beam radiotherapy system on phantoms and breast patients

“…3 Our group has recently presented a design of a cost-effective 200 kV kilovoltage arc therapy (KVAT) x-ray source consisting of a large tungsten anode and a custom linear collimator, which collimates incident photons into a number of converging beamlets intersecting at the radiation isocenter. 4 By using converging beamlets of kV photons, the dose to healthy tissues above a deep-seated tumor is reduced by spreading the photons over a larger area. At the site of the tumor all of the beams converge and deliver dose higher than that delivered to the surrounding healthy tissue.…”

Inverse optimization of low‐cost kilovoltage x‐ray arc therapy plans

“…Collimator design parameters are listed in Table . These values were determined through computer optimization and MC modeling . Experimental validation of a source of similar design and energy was performed previously by our group .…”

“…All KVAT dose calculations were run with the DOSXYZnrc package of EGSnrc and the dose to medium was reported. The dose calculated by DOSXYZnrc was converted into dose rate in cGy/min using the conversion factor of 2.96 × 10 19 particles per minute of irradiation at a tube current of 200 mA …”

“…These values were determined through computer optimization and MC modeling. 11 Experimental validation of a source of similar design and energy was performed previously by our group. 12 The source-to-axis distance (SAD), which is measured from the bottom of the collimator to isocenter, was fixed at 30 cm.…”

“…The dose calculated by DOSXYZnrc was converted into dose rate in cGy/min using the conversion factor of 2.96 9 10 19 particles per minute of irradiation at a tube current of 200 mA. 11 For the KVAT simulations, computed tomography (CT) images of each patient were converted into an.egsphant file with 2.5 mm 9 2.5 mm 9 2.5 mm voxels using the Radify (LifeLine Software, Inc., Austin, TX, USA) web application. Four materials were used for each patient phantom.…”