The first purpose of this paper is to shed some new light on the old question of selecting the number of beams in intensity-modulated radiation therapy (IMRT). The second purpose is to illuminate the related issue of discrete static beam angles versus rotational techniques, which has recently re-surfaced due to the advancement of volumetric modulated arc therapy (VMAT). A specific objective is ...

Volumetric modulated arc therapy (VMAT) has found widespread clinical application in recent years. A large number of treatment planning studies have evaluated the potential for VMAT for different disease sites based on the currently available commercial implementations of VMAT planning. In contrast, literature on the underlying mathematical optimization methods used in treatment planning is sca...

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...

Two quality control devices, light-field device and radiation-field device, have been specially designed to facilitate the clinical implementation of conformal dynamic arc treatment (CDAT) and intensity modulated radiation therapy (IMRT). With the devices, the light field as well as the radiation field, projected from the individual beam at any treatment position (i.e. arbitrary gantry angle) c...

In intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT), the use of posterior oblique beams has become common. Beam attenuation by the treatment couch is not negligible when the couch is in the beam portal. In this study, we established the relationship of relative dose vs. beam angle for two Varian 21EX linacs, one equipped with the Exact couch (standard cou...

background: to analyze the dosimetric and radio biologic advantages between intensity modulated radiotherapy (imrt) and 3 dimensional conformal radiotherapy (3dcrt) and selection of optimal photon energy for imrt treatments. material and methods: 24 patients with localized prostate carcinoma were planned for 3dcrt and imrt techniques. radiation dose of 54 gy with 2 gy/fraction, was planned to p...

Introduction: Radiotherapy is one of the effective methods in the treatment of cancer. In the recent methods of radiotherapy, intensity modulated radiotherapy (IMRT) technique by compensators is used. when photon beam passes the compensator, scattered photons can be generated within the compensator. The presence of scattered photons may complicate the design of compensators as...

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...