This study investigates the feasibility and applicability of cone beam CT for a megavoltage therapeutic LINAC. A Rando head phantom was irradiated using the 15 MV beam of a Varian 2100C LINAC at MSKCC for gantry angles from -102° to 102° with a 2° increment. The projection image for each gantry angle was obtained using a Varian Mark II EPID. Reference images without phantom were also collected ...

A method of reconstructing three-dimensional, in vivo dose distributions delivered by intensity-modulated radiotherapy (IMRT) is presented. A proof-of-principle experiment is described where an inverse-planned IMRT treatment is delivered to an anthropomorphic phantom. The exact position of the phantom at the time of treatment is measured by acquiring megavoltage CT data with the treatment beam ...

ADVERTISEMENT RETURN TO ISSUEEditorialNEXTSustainable PhotonsPhillip Christopher*Phillip ChristopherUniversity of California, Santa Barbara, California 93106-5080, United States*[email protected]More by Phillip Christopherhttps://orcid.org/0000-0002-4898-5510 and Prashant KamatPrashant KamatUniversity Notre Dame, Indiana 46556, StatesMore Kamathttps://orcid.org/0000-0002-2465-6819Cite this: ACS...

The production of high quality pretreatment images plays an increasing role in image-guided radiotherapy (IGRT) and adaptive radiation therapy (ART). Megavoltage cone-beam computed tomography (MV-CBCT) is the simplest solution of all the commercially available volumetric imaging systems for localization. It also suffers the most from relatively poor contrast due to the energy range of the imagi...

In the megavoltage energy range although the mass attenuation coefficients of different bones do not vary by more than 10%, it has been estimated that a simple tissue model containing a single-bone composition could cause errors of up to 10% in the calculated dose distribution. In the kilovoltage energy range, the variation in mass attenuation coefficients of the bones is several times greater,...

MRI is often used in tumor localization for radiotherapy treatment planning, with gadolinium (Gd)-containing materials often introduced as a contrast agent. Motexafin gadolinium is a novel radiosensitizer currently being studied in clinical trials. The nanoparticle technologies can target tumors with high concentration of high-Z materials. This Monte Carlo study is the first detailed quantitati...

PURPOSE This study investigates a large-area plane-parallel ionization chamber (LAC) for measurements of dose-area product in water (DAPw ) in megavoltage (MV) photon fields. METHODS Uniformity of electrode separation of the LAC (PTW34070 Bragg Peak Chamber, sensitive volume diameter: 8.16 cm) was measured using high-resolution microCT. Signal dependence on angle α of beam incidence for squar...

The current UK code of practice for high-energy photon therapy dosimetry (Lillicrap et al 1990 Phys. Med. Biol. 35 1355-60) gives instructions for measuring absorbed dose to water under reference conditions for megavoltage photons. The reference conditions and the index used to specify beam quality require that a machine be able to set a 10 cm × 10 cm field at the point of measurement. TomoTher...

It has been thought that adult nervous tissues show a remarkable degree of resistance to injury by x rays. Clemedson and Nelson (1960), after a comprehensive review of the literature, state: " Nervous tissues, especially of adult animals, show a remarkable radio-resistance." In the past few years, however, experimental work on animals (Lander, 1959; Innes and Carsten, 1961) suggests that delaye...