Exit fluence analysis using portal dosimetry in volumetric modulated arc therapy

Abstract

It is found from this study that the variation due to patient anatomy and interfraction organ motion is significant.

Clinical examples of 3D dose distribution reconstruction, based on the actual MLC leaves movement, for dynamic treatment techniques

“…Measuring fluence maps using EPID matirx is one of the standard QA methods in radiotherapy. 13 In-phantom measurements are obtained before the first treatment session. The aim of this method is to compare the calculated (theoretical) fluence maps with the measured (actual) ones.…”

Analysis of dose distribution reproducibility based on a fluence map of in vivo transit dose using an electronic portal imaging device

“…This decrease indicates a change in the dose distribution in patients when compared to the first fraction [17]. Morphological changes impact a patient's dose distribution, allowing for an increase in the dose for the organ at risk (OAR) [11,13,[18][19][20]. Increases and decreases in body weight are a form of morphological change [18,19].…”

“…Morphological changes impact a patient's dose distribution, allowing for an increase in the dose for the organ at risk (OAR) [11,13,[18][19][20]. Increases and decreases in body weight are a form of morphological change [18,19]. Weight loss is a common factor that can occur during radiotherapy [11].…”

“…Changes in the position of internal organs and the body's contours can be influenced by body weight, thus impacting the attenuation of fluence in the body [19]. The research of Choi, Jo [21] showed that the average D 95% at the target was 98% due to an increase of 2 cm or more in body contours.…”

Commissioning and Acceptance Testing of the existing linear accelerator upgraded to volumetric modulated arc therapy

“…It converts the pixel data to absolute dose. [8][9][10][11] Several studies of dose-response characteristics have shown that a-Si EPIDs are suitable for dose verification. These studies have shown that the pixel signal is approximately linear with dose and can be converted to absolute dose by measuring the response over a wide range of parameters.…”