International Commission On Radiological Units And Measurements Research Articles

Study of positional dependence of dose to bladder, pelvic wall and rectal points in High-Dose-Rate Brachytherapy in cervical cancer patients

The objective of the study is to examine the variation in doses to, Bladder, pelvic wall and Rectal Points when a patient is simulated in Supine (S Position) and Lithotomy M shaped positions (LM Position), respectively as part of Intracavitary Brachytherapy in Cervical Cancer patients. Patients (n = 19) were simulated and orthogonal images were taken in S Position and LM Positions on a physical simulator. Digital orthogonal X-ray images were transferred to Brachyvision Treatment Planning System via Dicom to generate treatment plans. Radio opaque dye of 7 ml was injected into the Foley bulb for identification and digitization of International Commission on Radiological Units and Measurements (ICRU) Bladder point. Pelvic side wall points were marked in accordance with ICRU 38 recommendations. A Rectal tube containing dummy source marker wire was used to identify Rectal Point. Students’t-test was used to analyze the results. Doses in LM Position were lower and statistically significant when compared to S Position for ICRU Bladder Point, pelvic walls and Rectal Point. It was observed that movement of applicator could be the reason for the variations in doses between the two positions. Bladder, pelvic wall and rectal points systematically registered lower doses in LM Position as compared to S Position.

FURTHER STUDIES OF SOME TL CHARACTERISTICS OF MgB4O7:Dy, Na PHOSPHOR

Nowadays, the pacific use of ionizing radiation has attracted a great deal of attention in medicine, as well as in radiodiagnostic, and radiotherapy. However to avoid unnecessary irradiations to the healthy tissue, a strict quality control is required. This has led to the development of a new dosimeter equivalent to the tissue that could be highly suitable for the radiation dosimetry. The borate of magnesium with its low effective atomic number (Z eff ), is considered equivalent to the human-tissue. For this reason, in this work, we present the results obtained of the thermoluminescent characterization of this material. The test that was carried out includes the lower detection limit, sensitivity, reproducibility of the TL measurement, stability of information (fading), and TL response as a function of the delivered dose and energy response, which are recommended by the International Commission on Radiological Units and Measurements (ICRU) and International Commission on Radiological Protection (ICRP). Two different concentrations of Dy activator were used i.e. 1.25 (batch A) and 1.5 (batch B) mol%. Meanwhile, the Na activator was 0.5 mol% in both cases. The results show that this new thermoluminescent material is adequate for radiation dosimetry in different medical applications.

SU‐GG‐T‐346: Accurate Simulation for Therapeutic Protons Range‐Energy and Range‐Density Tables

Purpose: The purpose of this work is to generate accurate range‐energy and range‐density tables for therapeutic protons using Monte Carlo simulation in water phantom. Method and Materials The percentage depth dose and the depth peak dose was calculated using Monte Carlo simulation for protons. The simulation was based on Monte Carlo code, MCNPX in water phantom with protons energy ranging from 40 MeV increasing by 10 to 250 MeV. The calculation of the three dimension dose matrix was performed using a 2 × 2 × 1 mm∧3 voxels in the depth peak range in water phantom. The pencil beam was used and the source was uniformly distributed in area with beam diameter as 20 mm. A 3,000,000 history was used in each individual simulation with uncertainty controlled less than 1.0%. Results: The total 22 data points of simulated depth peak were compared to two widely used proton range‐energy tables from International Commission on Radiological Units and Measurements (ICRU) Report 49 and from Data Nuclear Data Tables (DNDT). The simulated range‐energy curve matches very well with ICRU and DNDT with coefficient of determination equal to 1. The difference of the simulation and measurements is 1.17% at maximum and 0.70% at average compared to ICRU, 1.15% and 0.37% compared to DNDT respectively. The relation of range‐density was determined with water density ranging from 0.4 to 2.0 g/cm^3. The exponential relation of range‐density gives very closely matched estimation to the simulated value with the coefficient of determination as 0.9999. Conclusion: The simulated proton range‐energy matches very well to two widely used measurements. The accurate Monte Carlo simulation provides a close benchmark for existed measurements. The simulation offers the chance to replace the infinite experiments for each detailed energy and density. The simulation also expands the feasibility of accurate simulation in heterogeneity.

Radiance and particle fluence

The concepts of radiance and fluence are fundamental to the description of a radiation field. The International Commission on Radiological Units and Measurements (ICRU) has defined fluence in terms of the number of the radiation particles crossing a small sampling sphere. A second definition has been proposed in which the length of track segments contained within any sampling volume are used to calculate the incident fluence. This approach is often used in Monte Carlo simulations of individual particle tracks, allowing the fluence to be scored in small volumes of any shape. In this paper we stress that the second definition generalizes the classical (ICRU) concept of fluence. We also identify the assumptions inherent in the two definitions of fluence and prove their equivalence for the case of straight-line particle trajectories.

Methods for the Calibration of Photon Personnel Dosemeters in Terms of the Ambient Dose Equivalent

A series of Monte Carlo computer calculations has been made in order to study the relationships between the quantity measured (exposure or air kerma) and the quantity desired (ambient dose equivalent) for photon irradiations. The types of irradiations considered were those required by the National Voluntary Laboratory Accreditation Program and the US Department of Energy Laboratory Accreditation Program. It was found that a dosemeter covered with 1 g.cm −2 of either polymethylmethacrylate (PMMA) or an International Commission on Radiological Units and Measurements (ICRU) four-element tissue mixture, and irradiated on a rectangular 30×30×15 cm 3 PMMA phantom, can yield a reasonable approximation to the ambient dose equivlent

Report to the International Executive Committee of the Eleventh International Congress of Radiology from the International Commission on Radiological Units and Measurements (ICRU)

Before turning to the actual program in which the ICRU has been engaged since the Tenth International Congress of Radiology, it would seem appropriate to mention some of the results of the work accomplished prior to the Tenth Congress. As was reported to the International Executive Committee in 1962, ICRU efforts between 1959 and 1962 resulted in the publication of six major reports: ICRU Report 10a on Radiation Quantities and Units (NBS Handbook 84) ICRU Report 10b on Physical Aspects of Irradiation (NBS Handbook 85) ICRU Report 10c on Radioactivity (NBS Handbook 86) ICRU Report 10d on Clinical Dosimetry (NBS Handbook 87) ICRU Report 10e on Radiobiological Dosimetry (NBS Handbook 88) ICRU Report 10f on Methods of Evaluating Radiological Equipment and Materials (NBS Handbook 89). These reports represent, perhaps, the most comprehensive effort which the ICRU has made to meet the needs for precise and exact concepts of radiation quantities and units and for the exposition of appropriate means of applying these concepts to practical work in radiology and radiobiology. The Commission is gratified by the acceptance these reports have received. There is much evidence that these reports have had a significant, progressive impact on development in the many fields to which the recommendations in them have been applied. Development of New Substructure and Mode of Operation Since the last report to the Executive Committee (August 1962), the ICRU has devoted itself principally to the elaboration of the new substructure and mode of operation adopted by the Commission in 1962, and to the utilization of this new substructure for the initiation of new projects. The Commission defined three broad areas of concern to the ICRU—Activity, Radiation, and Problems of Joint Interest to the ICRU and the International Commission on Radiological Protection (ICRP). The ICRU divided these three major areas into eight sub-areas with which the Commission expects to be primarily concerned during the next few years. The division of work agreed upon is as follows: I. Activity A. Fundamental Physical Parameters and Measurement Technics B. Medical and Biological Applications II. Radiation A. Fundamental Physical Parameters B. X Rays, Gamma Rays, and Electrons C. Neutrons and Heavy Particles D. Medical and Biological Applications (Therapy) E. Medical and Biological Applications (Diagnosis) III. Problems of Joint Interest to the ICRU and the ICRP A. Radiation Protection Instrumentation and Its Application The Commission has established eight Planning Boards to guide ICRU activities in each of the sub-areas and named Commission Sponsors to provide liaison between the Commission and the Planning Boards. The constitution of the Planning Boards is now essentially complete and their members and Commission Sponsors are listed in Annex 1 of this report.

PHYSICAL TERMINOLOGY IN RADIOLOGY.

Do you specify radiation exposure or radiation dose in R? What is the dose-equivalent you receive in a typical working year? If you are working with fast neutrons, what quality factor should you apply? If you have a supervoltage x-ray machine, what is the Mv of the radiation it produces ? What is the average quantum energy produced by your machine in Mev? All these questions involve an understanding of radiological terminology, and some involve a knowledge of new terminology recently introduced by the International Commission on Radiological Units and Measurements (ICRU). One of the most important prerequisites for precision and ease in the communication of scientific and medical data is a specific, generally accepted terminology. In radiological science the ICRU is the fountain-head of recommended usage. One of the several ways in which the findings of this Commission reach practicing radiologists and associated scientists is through the medium of the professional journals. Radiology has long been intere...

Methods of Evaluating; Radiological Equipment and Materials; Recommendations of the International Commission on Radiological Units and Measurements (ICRU); Report 10f 1962

Methods of Evaluating; Radiological Equipment and Materials; Recommendations of the International Commission on Radiological Units and Measurements (ICRU); Report 10f 1962

Absorbed Dose in Biological Specimens Irradiated Externally with Cobalt-60 Gamma Radiation

A persistent problem in radiobiology is the need to express the absorbed dose received by externally irradiated biological specimens of a variety of shapes and sizes when only the exposure (formerly called exposure dose) at some reference point can be conveniently measured. In the case of very small specimens or the desirable but less convenient circumstances in which larger specimens are homogeneously irradiated (e.g., reference 1), the application of conversion factors from exposure to absorbed dose taken from such texts as The Report of the International Commission on Radiological Units and Measurements (ICRU) 1959 (2) may be sufficient to describe the average absorbed dose to the specimen. However, when large specimens are inhomogeneously irradiated, neither the average dose nor the variations in absorbed dose within the specimen can be adequately described in this way. This problem is neglected in many radiobiological experiments, but in some cases it has been solved by detailed study of the particular exposure circumstances employed. The purpose of this experimental study is to provide data which can be directly used with sufficient accuracy for most purposes to determine the magnitude and range of the absorbed dose to biological specimens of varying size and shape irradiated with Co60 y-rays. The data may also be applicable, with only minor modifications, to other y-ray sources such as radium and Csl137. In radiobiological experiments the most convenient and widely used method of exposure is to place the specimen at a point in a large beam or field of y-rays so that the specimen is completely irradiated. The exposure rate at the point is most frequently measured in air with a calibrated ionization chamber. The specimen is usually placed with its center at the point of measurement and its long axis perpendicular to the field or beam direction. The information desired includes: (1) the average absorbed dose to the specimen;

Report to the International Executive Committee of the Tenth International Congress of Radiology from the International Commission on Radiological Units and Measurements (ICRU)

Report to the International Executive Committee of the Tenth International Congress of Radiology from the International Commission on Radiological Units and Measurements (ICRU)

Report of the International Commission on Radiological Units and Measurements (ICRU)

The ICRU has been unusually active since its meeting in 1953. This activity has been due to a number of reasons: One was the introduction of a new quantity and unit for radiation measurement; another has been due to the necessary collaboration with the ICRP in radiation protection problems of global interest; and a third relates to the necessity of collaboration with numerous other international bodies having certain interests in common with those of the ICRU. The following meetings have been held: 1. Geneva, April 1956, for ten days. 2. Mexico City, July 1956, for one day. 3. New York, November 1956, for ten days, in conjunction with the ICRP, to organize a joint study for the U. N. Scientific Committee on the Effects of Atomic Radiations. 4. Geneva, April 1957, for ten days with the ICRP. 5. Geneva, September 1958, for twelve days. 6. Munich, July 1959, for three days. 7. In addition, committees and task groups of committees have met on several occasions. An extensive report on radiation units, measurements, and dosimetry which began in 1955 was completed and published early in 19571. This included many new data and other material necessary when radiation measurements are made and/or expressed in energy units (rads). Much of this has involved the development of new data by individual workers. Since publication of the 1957 report, the entire material has been under further study and extension. Most of this was reviewed at the meetings in Geneva in 1958 and Munich in 1959, and preparation of the 1959 report is essentially completed. The joint study with the ICRP was published in 1957,2 after submission to the U. N. Scientific Committee. As a result of conferences in 1955, the ICRU established a consultative status with the World Health Organization. This has proved to be a very fruitful relationship in that WHO has aided the ICRU materially in its meetings. We have also established a consultative relationship with the International Bureau of Weights and Measures (BIPM). At a meeting with the BIPM in April 1959, it was established that the BIPM would, for the time being, look to the ICRU for primary guidance in matters of radiation units and standards. Establishment of a consultative status with the International Atomic Energy Agency is now under consideration. Arrangements have been made with several other international bodies to exchange observers at meetings. During the past few years, it has become increasingly evident that the scope of interest and concern of the ICRU has expanded considerably beyond that of radiology alone. It has been necessary to accept these challenges as they arose. The situation points up rather clearly that the future course of action of the ICRU must include close working relationships with international bodies in addition to the ICR. These matters have been discussed extensively with the ICRP but no conclusions have been reached. Costs of operating the ICRU have increased enormously, both in terms of money and manpower.

History of the international commission on radiological units and measurements (ICRU).

Abstract The International Commission on Radiological Units and Measurements was established in 1925 by the first International Congress of Radiology- and since that time has established the units that are used in radiation dosimetry. The roentgen was introduced in 1928 and the rad in 1953. Since 1953 the Committee's activities have broadened substantially and in its most recent studies provided much of the technical information and background necessary for the practical interpretation of radiation dose in terms of the rad. This report covers the work of the Commission as it has developed since its formation over 30 years ago.

Report of the International Commission on Radiological Units and Measurements

Report of the International Commission on Radiological Units and MeasurementsPublished Online:28 Jan 2014https://doi.org/10.1259/0007-1285-30-354-297SectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail AboutAbstractThe 1956 recommendations of the International Commission on Radiological Units and Measurements (ICRU) have been published as National Bureau of Standards Handbook 62. This report covers the recommendations of the ICRU as agreed upon at its meetings in Geneva in April 1956, and replaces its earlier report issued in 1953. The new report includes an extensive amount of basic information and data necessary to make radiation dose measurements in energy units (rads), and to convert data expressed in röntgens to the equivalent in energy units. Previous article Next article FiguresReferencesRelatedDetails Volume 30, Issue 354June 1957Pages: 281-336 © The British Institute of Radiology History Published onlineJanuary 28,2014 Metrics Download PDF