PURPOSE To develop an in-house software program that is able to calculate and generate the biological dose distribution and biological dose volume histogram by physical dose conversion using the linear-quadratic-linear (LQL) model. MATERIAL AND METHODS The Isobio software was developed using MATLAB version 2014b to calculate and generate the biological dose distribution and biological dose vo...

Introduction: The aim of this retrospective study was to evaluate the variations in delivered dose to the bladder, rectum, and femoral heads of prostate cancer patients during a course of treatment by image-guided radiation therapy (IGRT). Materials and Methods: Overall, 15 patients with prostate cancer were selected and. Each week, for each patient five consecutive cone beam computed tomograph...

This thesis introduces visibility histograms as a method for analyzing volumetric datasets. These histograms show how much the data points within a 3D dataset that have the same scalar value influence the image which is created by rendering the dataset with a particular transfer function and from a particular viewing direction. These histograms can be used to gain insights into the internal str...

PURPOSE The purpose of this study was to explore the correlation between the respiration-induced target motion and volume variation with the dosimetric variance on breast and organ at risk (OAR) during free breathing. METHODS AND MATERIALS After breast-conserving surgery, seventeen patients underwent respiration-synchronized 4DCT simulation scans during free breathing. Treatment planning was ...

Introduction: Multiple fields and presence of heterogeneities create complex dose distributions that need three dimensional dosimetry. In this work, we investigated MR-based MAGIC gel dosimetry as a three-dimensional dosimetry technique to measure the delivered dose to bladder and rectum in prostate radiation therapy. Materials and Methods: A heterogeneous slab phantom including bones was made....

PURPOSE The treatment of moving targets with intensity-modulated radiotherapy may introduce errors in dose delivery. The motion of tumors in the abdomen was studied using quantitative fluoroscopic analysis, and the effect on dose delivery to the target was studied. METHODS AND MATERIALS Fluoroscopy sessions for 7 patients with pancreas or liver tumors and fiducial clips were recorded, convert...

BACKGROUND AND PURPOSE The latency of a multileaf collimator (MLC) tracking system used to overcome respiratory motion causes misalignment of the treatment beam with respect to the gross tumour volume, which may result in reduced target coverage. This study investigates the magnitude of this effect. MATERIAL AND METHODS Simulated superior-inferior breathing motion was used to construct histog...

BACKGROUND This study evaluates the dose distribution of reversed planned tangential beam intensity modulated radiotherapy (IMRT) compared to standard wedged tangential beam three-dimensionally planned conformal radiotherapy (3D-CRT) of the chest wall in unselected postmastectomy breast cancer patients METHODS For 20 unselected subsequent postmastectomy breast cancer patients tangential beam ...