Radiotherapy could be considerably improved by the recent development of three-dimensional intensity-modulated radiation therapy. This technique allows the concept of so-called dose painting or adaptive dose distribution to be implemented with improved aligning of the dose distribution along the complex geometric arrangements of the tumour and the surround healthy critical structures. This enab...

Introduction: Modern radiotherapy treatment planning (RTTP) requires volumetric localisation of tumour and critical structures. 3dimensional computed tomography (CT) data is the preferred imaging modality in RTTP due to: spatial accuracy; electron density information; the speed of acquisition; the ability to image the patient in the treatment position and the visualisation of bony anatomy. Howe...

In a radiotherapy department having more than one linear accelerator, it is rather common to match the dose output of all machines. In particular, the recently developed flattening filter free mode requires new investigations regarding the feasibility of matching and the consequences for quality assurance and workload. This refers also to the beam model of the radiotherapy treatment planning sy...

introduction: 99mtc-mibi has been proposed for use as an imaging agent for various tumors, including breast cancer, lung cancer, lymphomas, melanomas and brain neoplastic lesions. brain tumors are very common and radiotherapy being major part of treatment following surgery. after radiotherapy, deteriorating clinical status can be due to either radiation necrosis or recurrent tumor. computed tom...

A noninvasive localization and immobilization technique that facilitates planning and accurate delivery of both intensity modulated radiotherapy (IMRT) and linac based stereotactic radiotherapy (SRT) of intracranial tumors has been developed and clinically tested. Immobilization of a patient was based on a commercially available Gill-Thomas-Cossman (GTC) relocatable frame. A stereotactic locali...

PURPOSE To improve patient safety and treatment quality, verification of dose delivery in radiotherapy is desirable. We present a simple, easy-to-implement, open-source method for in vivo planar dosimetry of conformal radiotherapy by electronic portal imaging device (EPID). METHODS Correlation ratios, which relate dose in the mid-depth of slab phantoms to transit EPID signal, were determined ...

In modern radiotherapy, verification of the treatment to ensure the target receives the prescribed dose and normal tissues are optimally spared has become essential. Several forms of image guidance are available for this purpose. The most commonly used forms of image guidance are based on kilovolt or megavolt x-ray imaging. Image guidance can also be performed with non-harmful ultrasound (US) w...

Intensity modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3D CRT) are two treatment modalities in prostate cancer, which provide acceptable dose distribution in tumor region with sparing the surrounding normal tissues. IMRT is based on inverse planning optimization; in which, intensity of beams is modified by using multileaf collimators and also compensator...

Introduction. In the International Code of Practice for dosimetry TRS-398 published by International Atomic Energy Agency (IAEA), water is recommended as the reference medium for the determination of absorbed dose for high-energy electron beams. Plastic phantoms may be used under certain circumstances for electron beam dosimetry for beam qualities R50 < 4g/cm2 (E0 below 10 MeV). In our study, w...

The feasibility of delivering craniospinal irradiation (CSI) with TomoDirect is investigated. A method is proposed to generate TomoDirect plans using standard three-dimensional (3D) beam arrangements on Tomotherapy with junctioning of these fields to minimize hot or cold spots at the cranial/spinal junction. These plans are evaluated and compared to a helical Tomotherapy and a three-dimensional...