Introduction: Today different uses of multileaf collimators(MLC) in different techniques of radiotherapy are common. Due to the use of this facility it is possible to have maximum radiation dose to target volumes and minimum radiation dose to critical tissues surronding treatment volumes. But there are numerouse Linear accelerators in IRAN without MLC. Because of high price of...

introduction: multileaf collimator (mlc) is state of the art among the radiation field shaping systems for conformal radiotherapy techniques. some advantages of this system are as follow: reduction of treatment time, higher precision in conforming the radiation field to the projection of the target volume and lowering the chance of errors made by technologists. the purpose of this research was ...

Multileaf collimator (MLC) positions should be precisely and independently mea-sured as a function of gantry angle as part of a comprehensive quality assurance (QA) program for volumetric-modulated arc therapy (VMAT). It is also ideal that such a QA program has the ability to relate MLC positional accuracy to patient-specific dosimetry in order to determine the clinical significance of any dete...

Introduction: Multileaf collimator (MLC) is state of the art among the radiation field shaping systems for conformal radiotherapy techniques. Some advantages of this system are as follow: reduction of treatment time, higher precision in conforming the radiation field to the projection of the target volume and lowering the chance of errors made by technologists. The purpose of this research was ...

introduction: in recent decades, several monte carlo codes have been introduced for research and medical applications. these methods provide both accurate and detailed calculation of particle transport from linear accelerators. the main drawback of monte carlo techniques is the extremely long computing time that is required in order to obtain a dose distribution with good statistical accuracy. ...

multileaf collimator (mlc) is among the radiation field shaping systems used for conformal radiotherapy and intensity modulation radiation therapy techniques. the mlc system that has been designed and fabricated in this study includes 52 leaves, 52 stepper motors, 2 dc motors, 16 programmable logic controllers (plcs) and one human machine interface (hmi). this system can be mounted on conventio...

background: high-energy linear accelerator (linac) is a valuable tool and the most commonly device for external beam radiation treatments in cancer patients. in the linac head, high-energy photons with energies above the threshold of interaction produce photoneutrons. these photoneutrons deliver the extra dose to the patients in the planning treatment and increase the risk of secondary cancer. ...

introduction intensity modulated radiation therapy (imrt) has made a significant progress in radiation therapy centers in recent years. in this method, each radiation beam is divided into many subfields that create a field with a modulated intensity. considering the complexity of this method, the quality control for imrt is a topic of interest for researchers. this article is about the various ...

In advanced, intensity-modulated external radiotherapy facility, the multileaf collimator has a decisive role in the beam modulation by creating multiple segments or dynamically varying field shapes to deliver a uniform dose distribution to the target with maximum sparing of normal tissues. The position of each MLC leaf has become more critical for intensity-modulated delivery (step-and-shoot I...

A method is proposed for generating dynamic wedges spanning the entire field width, defined as the collimator opening in the wedged direction, without changes to existing hardware. The technique approximates the fluence pattern of a dynamic wedge by sequentially closing the leaves of a 120-leaf multileaf collimator (MLC). Closure times for the individual leaves were derived by extending the seg...