Intensity-modulated radiotherapy (IMRT) has become an effective tool for cancer treatment with radiation. However, even expert radiation planners still need to spend a substantial amount of time manually adjusting IMRT optimization parameters such as dose limits and costlet weights in order to obtain a clinically acceptable plan. In this paper, we describe two main advances that simplify the pa...

INTRODUCTION Results of use of methodology for VMAT commissioning and quality assurance, utilizing both control point tests and dosimetric measurements are presented. METHODS AND MATERIALS A generalizable, phantom measurement approach is used to characterize the accuracy of the measurement system. Correction for angular response of the measurement system and inclusion of couch structures are ...

Benchmarking Flattening Filter-Free Photons for IMRT/VMAT using TG119 By Sarah Ashmeg Graduate Program in Medical Physics Duke University Date: _______________________ Approved: ___________________________ Jennifer O’Daniel, Co-Supervisor ___________________________ Fang-Fang Yin, Co-Supervisor ___________________________ Timothy Turkington An abstract of a thesis submitted in partial fulfillme...

background: an effective method for management of large and bulky malignant tumors. this treatment modality is also known as specially fractionated radiation therapy (sfrt). in this treatment technique a grid block converted the open radiation field into a series of pencil beams. dosimetric characteristics of an external beam grid radiation field have been investigated using experimental and mo...

All radiation therapy treatment planning relies on accurate dose calculation. Uncertainties in dosimetric prediction can significantly degrade an otherwise optimal plan. In this work, we introduce a robust optimization method which handles dosimetric errors and warrants for high-quality IMRT plans. Unlike other dose error estimations, we do not rely on the detailed knowledge about the sources o...

This paper presents an alternative method to tune Monte Carlo electron beam parameters to match measured data using a minimal set of variables in order to reduce the model setup time prior to clinical implementation of the model. Monte Carlo calculations provide the possibility of a powerful treatment planning verification technique. The nonstandardized and nonautomated process of tuning the re...

Suggestions for topics suitable for these Point/Counterpoint debates should be addressed to Colin G. Orton, Professor Emeritus, Wayne State University, Detroit: [email protected]. Persons participating in Point/Counterpoint discussions are selected for their knowledge and communicative skill. Their positions for or against a proposition may or may not reflect their personal opinions or the pos...

AAPM Task Group 119 has produced quantitative confidence limits as baseline expectation values for IMRT commissioning. A set of test cases was developed to assess the overall accuracy of planning and delivery of IMRT treatments. Each test uses contours of targets and avoidance structures drawn within rectangular phantoms. These tests were planned, delivered, measured, and analyzed by nine facil...

In this study we investigate the effect of detector size in the dosimetry of small fields and steep dose gradients with a particular emphasis on IMRT measurements. Comparisons of calculated and measured cross-profiles and absolute dose values of IMRT treatment plans are presented. As a consequence of the finite size of the detector that was used for the commissioning of the IMRT tool, local dis...

Intensity modulated radiation therapy (IMRT) treatment planning typically considers beam optimization and beam delivery as separate tasks. Following optimization, a multi-leaf collimator (MLC) or other beam delivery device is used to generate fluence patterns for patient treatment delivery. Due to limitations and characteristics of the MLC, the deliverable intensity distributions often differ f...