Purpose: To study and compare the dose response curves of the new GafChromic EBT3 film for megavoltage and kilovoltage x-ray beams, with different spatial resolutions. Methods: EBT3 films (lot#A101711-02) were exposed to each x-ray beam (6 MV, 15 MV, and 50 kV) at 7 dose values (50 3200 cGy). Each film piece was scanned three consecutive times in the center of Epson 10000XL flatbed scanner in 4...

background: 7-lif: mg,cu,p (gr-207a) is one kind of thermo-luminescent dosimeters (tld) which can be used in diagnostic radiology and radiotherapy applications. because of having suitable properties such as good sensitivity, small size and being tissue equivalent, thermo-luminescent dosimetry has been one of the most important techniques in medicine over many years. choosing a correct energy fo...

Megavoltage X-ray sources are commonly used for therapy planning, and knowledge of their spectral distribution is important for accurate dose calculations. There are many methods that could provide reasonable estimations of Megavoltage X-ray spectra, when very accurate attenuation data or at least very good set of initial guesses of the spectra are available. We present here a novel method, whi...

The energy dependence of the dose response of EBT Gafchromic film is assessed over a broad energy range, from superficial to megavoltage X-rays. The film is auto-developing and sensitive, it provides accurate dose assessment of low doses (about 1-2 Gy) used in radiotherapy. The energy dependence of the response of EBT film was found to be very weak: the variations do not exceed 10% over the ran...

A digital phantom was created from a CT scan of patient’s head and employed together with GATE 8.2 Monte Carlo modeling linear accelerator nominal 6 MV energy to simulate an irradiation geometry for typical tumor volume centrally within the brain region. Although simplistic in arrangement, this setup considered appropriate demonstrate dose enhancements that may be expected megavoltage external ...

BACKGROUND AND PURPOSE A comprehensive dosimetry intercomparison has been carried out involving all the radiotherapy centres, all external beam modalities and every radiotherapy treatment unit in the Republic of Ireland. MATERIALS AND METHODS Reference point measurements were made for all megavoltage photon beams. Doses were also investigated in planned three-field distributions. One of these...

Ophthalmic Graves' disease and histiocytosis X involving the orbit are occasionally refractory to treatment, so that vision may be threatened. In these situations megavoltage external beam radiotherapy should be employed, and the indications for this treatment are discussed. A highly accurate technique is described, using precise planning with information obtained from high definition CT scans,...

The dose distributions for a patient with cancer involving the sternum were calculated for both a kilovoltage x-ray beam and a megavoltage electron beam. The minimum target dose and dose uniformity over the target volume were significantly better using electrons (90%-101%) than kilovoltage x-rays (68%-119%). The calculated lung dose and integral patient dose were also less for electrons than ki...

In external beam radiation therapy (EBRT), the quality assurance (QA) of the radiation beam is crucial to the accurate delivery of the prescribed dose to the patient. One of the dosimetric parameters that require monitoring is the beam output, specified as the dose rate on the central axis under reference conditions. The aim of this project was to validate dose rate calibration of megavoltage p...

Multifunctional nanoprobes have great potential as effective radiosensitizers and drug carriers. RGD-modified gold nanorods could increase the uptake of nanoparticles via receptor-mediated endocytosis in integrin alphaV beta3-overexpressing breast cancer cells, which could enhance the effects of radiation on tumor cells, leading to further radiosensitization. The purpose of our study was to dem...