3D dose verification for advanced radiotherapy
... dosimetry is presented in Chapter 2, where a review of published methods of performing dosimetry with EPIDs is given. This review focuses on the dosimetric characteristics
of EPIDs, the various ways of calibrating an EPID for dosimetry and application of the
EPID for transmission based and non-trans ...
Dosimetry in diagnostic radiology : an
... Standards Dosimetry Laboratory (SSDL) network.
For some time now there has been a growing awareness that radiation
dose originating from medical diagnostic procedures in radiology is
contributing an increasing proportion of the total population dose. This has
been particularly evident for examinatio ...
Piranha Reference Manual - English - 5.5G
... Accessory to diagnostic X-ray equipment to be used as an electrometer. Together with external
probes it is to be used for independent service and quality control, as well as measurements of
kerma, kerma rate, kVp, tube current, exposure time, luminance, and illuminance within limitations
stated belo ...
ONR - Radiation shielding - Office for Nuclear Regulation
... radioactive sources. In general, wherever reasonably practicable, remote control
operations should be chosen in preference to manual handling. In cases where remote
control is not reasonably practicable, licensees should consider the use of tongs or
other similar handling aids for use with such sour ...
Diagnostic Reference Levels in Medical Imaging
... Approved by the Commission in Month 201X
Abstract-The International Commission on Radiological Protection (ICRP) first introduced
the term ‘diagnostic reference level’ (DRL) in Publication 73 (1996). The concept was
subsequently developed further, and practical guidance was provided in 2001. DRLs ha ...
PDF - IAEA Publications
... registered) does not imply any intention to infringe proprietary rights, nor should it be construed
as an endorsement or recommendation on the part of the IAEA.
The authors are responsible for having obtained the necessary permission for the IAEA
to reproduce, translate or use material from sources ...
portal dosimetry in radiotherapy
... In case of dose‐guided radiation therapy (DGRT), a treatment is adapted based on
direct dose measurements in combination with the results of IGRT procedures. Dose
measurements can be done prior to treatment (pre‐treatment measurements) and
during treatment (in v ...
Biologically conformal radiation therapy and Monte
... Highly structured dose distributions can be delivered using intensitymodulated radiation therapy (IMRT). IMRT can thus reduce toxicity by
allowing a selective reduction of the dose to organs at risk, or allow dose
escalation with the aim to improve local control. In current clinical
practice, IMRT o ...
American Association of Physicists in Medicine 40th Annual
... A and B. Blocks C and D correspond primarily to the scientific sessions, however there is an occasional symposium in these time blocks
as well. Block E is reserved primarily to the afternoon symposia, however occasionally scientific sessions may be in these time blocks
as well. In general, Tracks 1 ...
European Journal of Medical Physics
... challenges for eye lens dosimetry are coming from the 2011 ICRP statement recommending a new and lower eye lens dose limit. Staff monitoring, aiming to assure the compliance with the dose limits, is in general
affected by large uncertainties for staff exposed near the radiation source
and partially ...
QA for helical tomotherapy: Report of the AAPM Task Group 148
... guidelines of newer technologies, there are several commercially available technologies that are sufficiently different
from C-arm type accelerators and require a unique set of QA
recommendations. One such technology is helical tomotherapy. It is therefore the intent of this Task Group Report to
Radiological Protection in Cone Beam Computed Tomography
... doses to patients without compromising diagnostic or clinical purpose. In recent years there
has been evaluation of practice that indicated that large number of imaging procedures have
not met the appropriateness guidelines. While ICRP has provided three levels of justification,
there is increasing ...
CLASSlCAL RADIATION THERAPY
... Photon fluence emitted by a point source of radiation varies inversely as a square of the
distance from the source. Although the clinical source (isotopic source or focal spot) for
external beam therapy has a finite size, the source-surface distance is usually chosen to
be large (280 cm) so that the ...
M C S O
... suggest that the use of a large wedge angle generates greater dose variation for both parallel
and perpendicular motions. The use of small field size with a large tumor motion results in the
loss of wedged dose distribution for both parallel and perpendicular motion. From these single
image guided radiation therapy applications for
... treatment. Node volumes shrunk to 17% of the initial volume, moved up 1.3 cm, and received up
to a 12% lower dose than that prescribed. It is shown that difficulties in imaging soft tissue in the
neck region are circumvented with ultrasound imaging, and after dosimetric verification it is
argued th ...
An X-ray Source Model and Characterization Method for Computing
... independent variables: the transverse-axis spectra; and the transverse- and radial-axis fluence
profiles. This work demonstrates that kV x-ray sources can be characterized using in-air
ionization chamber measurements of HVL and kerma profiles.
The characterization method and model are validated by c ...
Cone-Beam Computed Tomography Examinations of
... risk is determined by the cumulative dose of lifetime exposures to ionising radiation.
For an individual, the risk of stochastic effects can be regarded as relatively small
even in the case of relatively high cumulative doses. [66, p. 45] However, stochastic
effects can lead to a significant health ...
Tomotherapy vs IMRT (952kB PPT)
... - Linacs also provide the ability to deliver electron
fields. For many superficial targets, the use of
electrons from a linear accelerator is clearly a
better choice for its simplicity of dose delivery as
well as its higher skin dose and sharper dose
fall-off beyond the target.
- For the ability to ...
12 Physics and Clinical Aspects of Brachytherapy
... brachytherapy sources have half-lives ranging from
days to years. The length of a given brachytherapy
source’s half-life determines its shelf life, namely,
whether a source can be stored and used repeatedly
over a long period of time. Sources with shorter halflives, such as 125I and 103Pd sources, n ...
International Workshop on Monte Carlo Techniques in Medical
... The novel field of small animal radiotherapy (SmART) image-guided precision research aims to downscale radiotherapy to the size of small
animals, enabling the study of models for radiation response of normal tissue and tumors. Novel image-guided precision irradiators are now
available that greatly f ...
Assessing The Clinical Application Of The Van Herk Margin Formula
... The van Herk margin formula (VHMF) was developed to calculate the minimum margin on the
target to provide full coverage by 95% of the prescribed dose to 90% of the population.
However, this formula is based on an ideal dose profile model that is not realistic for lung
radiotherapy. The purpose of th ...
Development and Implementation of an Anthropomorphic Pediatric
... Table 3.11 2D Gamma Analysis Passing Rates for Spot Scanning Trials……………………..61
Figure 3.17 Images of the digitized film in the a) coronal and b) sagittal planes
for Spot Scanning Trial 3. ………………………………………………………..………………….62
Table 3.12 Spot Scanning Trials Average Distance to Agreement Results…………………. ...
Radiation Dose and Image Quality in Computed
... The aim of this study was to evaluate and compare the radiation doses imparted to
patients undergoing computed tomography (CT) examinations and image quality with
the use of automatic exposure control (AEC) and fixed tube current (FTC) techniques
using a head and body phantom in a Siemens emotion 16 ...
The sievert (symbol: Sv) is a derived unit of ionizing radiation dose in the International System of Units (SI). It is a measure of the health effect of low levels of ionizing radiation on the human body.Quantities that are measured in sieverts are intended to represent the stochastic health risk, which for radiation dose assessment is defined as the probability of cancer induction and genetic damage.The sievert is used for radiation dose quantities such as equivalent dose, effective dose, and committed dose. It is used both to represent the risk of the effect of external radiation from sources outside the body, and the effect of internal irradiation due to inhaled or ingested radioactive substances.Conventionally the sievert is not used for high dose rates of radiation which produce deterministic effects, which is the severity of acute tissue damage which is certain to happen. These effects are compared to the physical quantity absorbed dose measured by the unit gray (Gy).To enable consideration of stochastic health risk, calculations are performed to convert the physical quantity absorbed dose into equivalent and effective doses, the details of which depend on the radiation type and biological context. For applications in radiation protection and dosimetry assessment the International Commission on Radiological Protection (ICRP) and International Commission on Radiation Units and Measurements (ICRU) have published recommendations and data which are used to calculate these.The sievert is of fundamental importance in dosimetry and radiation protection, and is named after Rolf Maximilian Sievert, a Swedish medical physicist renowned for work on radiation dosage measurement and research into the biological effects of radiation. One sievert carries with it a 5.5% chance of eventually developing cancer.One sievert equals 100 rem. The rem is an older, non-SI unit of measurement.To enable a comprehensive view of the sievert this article deals with the definition of the sievert as an SI unit, summarises the recommendations of the ICRU and ICRP on how the sievert is calculated, includes a guide to the effects of ionizing radiation as measured in sieverts, and gives examples of approximate figures of dose uptake in certain situations.