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Speakers in this session will present overview and details of a specific rotation or feature of their Medical Physics Residency Program that is particularly exceptional and noteworthy. The featured rotations include foundational topics executed with exceptional acumen and innovative educational rotations perhaps not commonly found in Medical Physics Residency Programs. A site-specific clinical rotation will be described, where the medical physics resident follows the physician and medical resident for two weeks into patient consultations, simulation sessions, target contouring sessions, planning meetings with dosimetry, patient follow up visits, and tumor boards, to gain insight into the thought processes of the radiation oncologist. An incident learning rotation will be described where the residents learns about and practices evaluating clinical errors and investigates process improvements for the clinic. The residency environment at a Canadian medical physics residency program will be described, where the training and interactions with radiation oncology residents is integrated. And the first month rotation will be described, where the medical physics resident rotates through the clinical areas including simulation, dosimetry, and treatment units, gaining an overview of the clinical flow and meeting all the clinical staff to begin the residency program. This session will be of particular interest to residency programs who are interested in adopting or adapting these curricular ideas into their programs and to residency candidates who want to learn about programs already employing innovative practices. Learning Objectives: 1.To learn about exceptional and innovative clinical rotations or program features within existing Medical Physics Residency Programs. 2.To understand how to adopt/adapt innovative curricular designs into your own Medical Physics Residency Program, if appropriate.

Two-dimensional relative dose distributions have been measured around 125I brachytherapy seeds. The two seed models studied, models 6711 and 6712, were manufactured by the 3M Company. Silicon detectors immersed in water phantoms were used to measure the dose. A computerized data acquisition system that controlled the radial position of the diode and the angular rotation of the seed, as well as a manually controlled system were used to collect and store the data. Our results show that the two seed models have relative dose distributions which are quite similar; however, the absolute dose distributions are sufficiently different to warrant separate look-up tables for the two seed models. Additionally, our results are compared with dose distribution data previously obtained for the model 6711 seed.

This paper describes the beam characteristics and dosimetry measurements performed on the 6-MV photon beam of a new model of linear accelerator, three of which were recently introduced and installed in our institution. Percent depth dose and tissue maximum ratio tables for a variety of field sizes and depths, as well as other parameters used for treatment planning are presented. These accelerators are the first of their kind using both hardware and software tools to control interlocks. Checking procedures for these interlocks are available from the authors upon request. Comparison of characteristic parameters between these three new 6-MV linear accelerators and with the 6-MV beams of two other accelerators is also made.

Task Group 6 of the Diagnostic X-Ray Imaging Committee of the American Association of Physicists in Medicine (AAPM) was appointed to develop performance standards for diagnostic x-ray exposure meters. The recommendations as approved by the Diagnostic X-Ray Imaging Committee and the Science Council of the AAPM are delineated in this report and provide specifications on meter precision, calibration accuracy, calibration reference points, linearity, energy dependence, exposure rate dependence, leakage, amplification gain settings, directional dependence, the stem effect, constancy checks, and calibration intervals. The report summarizes recommendations for meters used in mammography, general purpose radiography including special procedures, computed tomography, and radiation safety surveys for x-ray radiography.

Introduction: Our task is to present information on the status of the Medical Physics practice in the different countries in Latin America. Because of its fundamental value, we would like to focus on the status of education and professional medical physics issues in the different countries. Purpose: The IAEA is interested in promoting harmonization of Medical Physics practice worldwide. As a contribution, we must first learn about the diverse status of the medical physics practice, possibilities and needs in the different countries of Latin America. Methods and Materials: The LAASC maintains a close communication with all (or most) Latin American Countries through the valuable contributions of our Latin American Liaisons and Consultants. We also rely heavily on the information and cooperation with ALFIM (The umbrella association of all Medical Physics Associations of the different countries in Latin America). This presentation is based on their contributions. Results: There is a large diversity in the status of Medical Physics practice in the different countries of Latin America. As expected, this discrepancy is mostly due to the different economy status in Latin American countries. However, in many instances the economic deficiencies are somehow compensated by the great creativity of medical physicists in the region. A large credit must be given to the extensive work of the IAEA and IOMP in the education and practice of the profession of medical physics in different countries of Latin America. Conclusions: LAASC always places emphasis on divulging to the Latin America medical physicists the professional and educational opportunities as well as the medical physics literature available through the AAPM website. Through the realization of ISEP workshops it has also been possible to exchange scientific information on the state of the art of the practice of medical physics, and also to divulge AAPM programs available to countries in development, such as PIP, International Affiliate, access to Medical Physics Journal and AAPM protocols, to name a few. We believe that through cooperation and work together with ALFIM, the AAPM could contribute to make a sustainable impact to the medical physics profession in Latin American Countries. Learning Objectives: 1. Understand the fundamental problems associated with the different medical physics practice levels encountered in Latin America 2. To become familiar with on‐going work in developing countries in Latin America in relation to medical physics education and professional recognition. 3. Learn how the AAPM could make a sustainable impact.

The Symposium is jointly sponsored by IOMP and IAEA with the International Affairs Committee of AAPM. So much is happening in large part of the world particularly when it comes to medical use of radiation and assessment of radiation doses to patients in over 50 developing countries, promoting harmonization of Medical Physics practice worldwide, and comparing doses with international standards and managing doses. In recent years many papers have been published in peer reviewed journals. Several premier international organizations have produced or are preparing publications impacting on the practice of medical physics. The momentum generated creates opportunities for collaboration and cooperation between medical physicists from developing countries and with those in America and Europe. AAPM members can contribute effectively in this very stimulating area of work. You can be part of the exercise of making a difference in the world, in making patients in need of diagnostic and therapeutic procedures safer and in improving the knowledge of colleagues in developing countries. Learning Objectives: 1. To learn about the MP practice in west Europe, in Asia, and in Latin America. 2. To learn about the MP practice in developing countries. 3. To become familiar with on‐going work in over 50 developing countries in Africa, Asia, Eastern Europe and Latin America on radiation protection of patients. 4. To understand the mechanism of cooperation and collaboration. 5. To consider development of new projects.

The relative dose distribution around the 103Pd model 200 implant seed was measured with a computerized data acquisition system employing a p-n junction silicon diode immersed in a water phantom. Data are acquired in polar coordinates by computer control of (1) the diode distance from the seed center and (2) the rotation angle of seed about a transverse axis. Transverse axis data are compared with thermoluminescent dosimeter (TLD) measurements and a Monte Carlo calculation by others.

Knowledge of the relative intensity distribution at the patient’s surface is essential for pencil beam calculations of three‐dimensional dose distributions for arbitrarily shaped electron beams. To calculate the relative intensity distribution, the spatial spread resulting from angular spread is convolved with a two‐dimensional step function whose shape corresponds to the applicator aperture. Two different approaches to obtain angular spread or the equivalent spatial spread are investigated. In the first method, the pencil beam angular spread is assumed to be Gaussian in shape. The angular spread constants (σθ ) are then obtained from the slopes of measured intensity profiles. In the second method, the angular spread, in the form of an array of numerical values, is obtained by the deconvolution of measured intensity profiles. After obtaining the angular spread, the calculation for convolution is done in a number of parallel planes normal to the central axis at various distances from the electron collimator. Intensity at any arbitrary point in space is computed by interpolating between intensity distributions in adjacent planes on either side of the point. The effects of variations in angular spread as a function of field size for two treatment machines, one with a scanned electron beam and the other with a scattering foil, have been studied. The consequences of assuming angular spread to be of Gaussian shape are also examined. The electron intensity calculation techniques described in this paper apply primarily to methods of dose calculations that employ pencil beams generated using Monte Carlo simulations.

Asymmetric fields defined by independent jaws can be used to split a beam or to match adjacent fields. We have extended a method originally developed for symmetric fields to calculate the dose for asymmetric fields. The dose to a point is computed as the product of the tissue maximum ratio (TMR), the off center ratio (OCR), and the inverse square factor. The TMR is computed from the measured central axis depth doses for symmetric fields. The OCR is obtained by multiplying the primary OCR (POCR) and the boundary factors (BF's) for the four jaws. The POCR's and BF's were derived from measured beam profiles, which include the effect of off-axis beam quality variations. Using this method, the beam profiles and isodose distributions for asymmetric fields of a 6-MV accelerator were calculated and compared with the measured data. The agreement is within experimental errors both in the penumbra region and along the central ray of the asymmetric field.