PURPOSE Volumetric modulated arc therapy (RapidArc; Varian Medical Systems, Palo Alto, CA) allows fast delivery of stereotactic radiotherapy for Stage I lung tumors. We investigated discrepancies between the calculated and delivered dose distributions, as well as the dosimetric impact of leaf interplay with breathing-induced tumor motion. METHODS AND MATERIALS In 20 consecutive patients with ...

In this work, we develop and test a matchline dosimetry analysis tool (MDAT) to examine the dose distribution within the abutment region of two or more adjoining radiotherapy fields that employ different blocking mechanisms and geometries in forming a match. This objective and quantitative tool uses calibrated radiographic film to measure the dose in the abutment region, and uses a frequency di...

Electronic portal imaging devices (EPIDs) are potentially valuable tools for linear accelerator quality assurance and for measuring and analyzing geometric variations in radiation treatment delivery. Geometric analysis is more robust if referenced against an absolute position such as the isocenter (collimator axis of rotation), allowing the observer to discriminate between various setup errors ...

Purpose: Motorized or dynamic wedge is routinely used nowadays to facilitate the work and reduce time on the treatment machine. However, this will necessitate keeping the Multileaf collimator (MLC) direction parallel to the chest wall. The aim of our work is to study the effect of Multileaf collimator in the perpendicular (┴) or parallel(//) direction on: target volume coverage, dose homogeneit...

The aim of this study is to assess the suitability of 5 mm millennium multileaf collimator (MMLC) for volumetric-modulated arc therapy (VMAT)-based lung stereotactic body radiotherapy (SBRT). Thirty lung SBRT patient treatment plans along with their planning target volumes (ranging from 2.01 cc to 150.11 cc) were transferred to an inhomogeneous lung phantom and retrospectively planned using VMA...

Lung cancer is the leading cause of cancer-related deaths worldwide. Radiotherapy is one of the main treatment modalities of lung cancer. However, the achievable accuracy of radiotherapy treatment is limited for lung-based tumors due to respiratory motion. Four-dimensional (4D) radiotherapy explicitly accounts for anatomic motion by characterizing the motion, creating a treatment plan that acco...

Introduction: Intensity modulated radiation therapy (IMRT) is one of the cancer treatment methods. It is important to selectively aim at the target in this way, which can be performed using a multileaf collimator (MLC). Materials and Methods: In order to specifically irradiate the target volume in radiotherapy to reduce the patient absorbed dose, the use of multileaf collimator has been investi...