3D DVH-based metric analysis versus per-beam planar analysis in IMRT pretreatment verification.

PURPOSE: To evaluate methods of pretreatment IMRT analysis, using real measurements performed with a commercial 2D detector array, for clinical relevance and accuracy by comparing clinical DVH parameters. METHODS: We divided the work into two parts. The first part consisted of six in-phantom tests aimed to study the sensitivity of the different analysis methods. Beam fluences, 3D dose distribution, and DVH of an unaltered original plan were compared to those of the delivered plan, in which an error had been intentionally introduced. The second part consisted of comparing gamma analysis with DVH metrics for 17 patient plans from various sites. Beam fluences were measured with the MapCHECK 2 detector, per-beam planar analysis was performed with the MapCHECK software, and 3D gamma analysis and the DVH evaluation were performed using 3DVH software. RESULTS: In a per-beam gamma analysis some of the tests yielded false positives or false negatives. However, the 3DVH software correctly described the DVH of the plan which included the error. The measured DVH from the plan with controlled error agreed with the planned DVH within 2% dose or 2% volume. We also found that a gamma criterion of 3%∕3 mm was too lax to detect some of the forced errors. Global analysis masked some problems, while local analysis magnified irrelevant errors at low doses. Small hotspots were missed for all metrics due to the spatial resolution of the detector panel. DVH analysis for patient plans revealed small differences between treatment plan calculations and 3DVH results, with the exception of very small volume structures such as the eyes and the lenses. Target coverage (D(98) and D(95)) of the measured plan was systematically lower than that predicted by the treatment planning system, while other DVH characteristics varied depending on the parameter and organ. CONCLUSIONS: We found no correlation between the gamma index and the clinical impact of a discrepancy for any of the gamma index evaluation possibilities (global, local, 2D, or 3D). Some of the tests yielded false positives or false negatives in a per-beam gamma analysis. However, they were correctly accounted for in a DVH analysis. We also showed that 3DVH software is reliable for our tests, and is a viable method for correlating planar discrepancies with clinical relevance by comparing the measured DVH of target and OAR's with clinical tolerance.

Core curriculum for medical physicists in radiology. Recommendations from an EFOMP/ESR working group.

Some years ago it was decided that a European curriculum should be developed for medical physicists professionally engaged in the support of clinical diagnostic imaging departments. With this in mind, EFOMP (European Federation of Organisations for Medical Physics) in association with ESR (European Society of Radiology) nominated an expert working group. This curriculum is now to hand. The curriculum is intended to promote best patient care in radiology departments through the harmonization of education and training of medical physicists to a high standard in diagnostic radiology. It is recommended that a medical physicist working in a radiology department should have an advanced level of professional expertise in X-ray imaging, and additionally, depending on local availability, should acquire knowledge and competencies in overseeing ultrasound imaging, nuclear medicine, and MRI technology. By demonstrating training to a standardized curriculum, medical physicists throughout Europe will enhance their mobility, while maintaining local high standards of medical physics expertise. This document also provides the basis for improved implementation of articles in the European medical exposure directives related to the medical physics expert. The curriculum is divided into three main sections: The first deals with general competencies in the principles of medical physics. The second section describes specific knowledge and skills required for a medical physicist (medical physics expert) to operate clinically in a department of diagnostic radiology. The final section outlines research skills that are also considered to be necessary and appropriate competencies in a career as medical physicist.

The updated ESTRO core curricula 2011 for clinicians, medical physicists and RTTs in radiotherapy/radiation oncology.

INTRODUCTION: In 2007 ESTRO proposed a revision and harmonisation of the core curricula for radiation oncologists, medical physicists and RTTs to encourage harmonised education programmes for the professional disciplines, to facilitate mobility between EU member states, to reflect the rapid development of the professions and to secure the best evidence-based education across Europe. MATERIAL AND METHODS: Working parties for each core curriculum were established and included a broad representation with geographic spread and different experience with education from the ESTRO Educational Committee, local representatives appointed by the National Societies and support from ESTRO staff. RESULTS: The revised curricula have been presented for the ESTRO community and endorsement is ongoing. All three curricula have been changed to competency based education and training, teaching methodology and assessment and include the recent introduction of the new dose planning and delivery techniques and the integration of drugs and radiation. The curricula can be downloaded at http://www.estro-education.org/europeantraining/Pages/EuropeanCurricula.aspx. CONCLUSION: The main objective of the ESTRO core curricula is to update and harmonise training of the radiation oncologists, medical physicists and RTTs in Europe. It is recommended that the authorities in charge of the respective training programmes throughout Europe harmonise their own curricula according to the common framework.

Radiation dose assessment in a 320-detector-row CT scanner used in cardiac imaging.

PURPOSE: In the present era of cone-beam CT scanners, the use of the standardized CTDI100 as a surrogate of the idealized CTDI is strongly discouraged and, consequently, so should be the use of the dose-length product (DLP) as an estimate of the total energy imparted to the patient. However, the DLP is still widely used as a reference quantity to normalize the effective dose for a given scan protocol mainly because the CTDI100 is an easy-to-measure quantity. The aim of this article is therefore to describe a method for radiation dose assessment in large cone-beam single axial scans, which leads to a straightforward estimation of the total energy imparted to the patient. The authors developed a method accessible to all medical physicists and easy to implement in clinical practice in an attempt to update the bridge between CT dosimetry and the estimation of the effective dose. METHODS: The authors used commercially available material and a simple mathematical model. The method described herein is based on the dosimetry paradigm introduced by the AAPM Task Group 111. It consists of measuring the dose profiles at the center and the periphery of a long body phantom with a commercial solid-state detector. A weighted dose profile is then calculated from these measurements. To calculate the CT dosimetric quantities analytically, a Gaussian function was fitted to the dose profile data. Furthermore, the Gaussian model has the power to condense the z-axis information of the dose profile in two parameters: The single-scan central dose, f(0), and the width of the profile, sigma. To check the energy dependence of the solid-state detector, the authors compared the dose profiles to measurements made with a small volume ion chamber. To validate the overall method, the authors compared the CTDI100 calculated analytically to the measurement made with a 100 mm pencil ion chamber. RESULTS: For the central and weighted dose profiles, the authors found a good agreement between the measured dose profile data and the fitted Gaussian functions. The solid-state detector had no energy dependence--within the energy range of interest--and the analytical model succeeded in reproducing the absolute dose values obtained with the pencil ion chamber. For the case of large cone-beam single axial scans, the quantity that better characterizes the total energy imparted to the patient is the weighted dose profile integral (DPI(w)). The DPI(w) can be easily determined from the two parameters that define the Gaussian functions: f(0) and sigma. The authors found that the DLP underestimated the total energy imparted to the patient by more than 20%. The authors also found that the calculated CT dosimetric quantities were higher than those displayed on the scanner console. CONCLUSIONS: The authors described and validated a method to assess radiation dose in large cone-beam single axial scans. This method offers a simple and more accurate estimation of the total energy imparted to the patient, thus offering the possibility to update the bridge between CT dosimetry and the estimation of the effective dose for cone-beam CT examinations in radiology, nuclear medicine, and radiation therapy.

The European Federation of Organisations for Medical Physics. Policy Statement No. 12: The present status of Medical Physics Education and Training in Europe. New perspectives and EFOMP recommendations.

A recently published EFOMP's survey on the status of Education and Training in Europe, has showed the important role played by the NMOs in the organisation of the Medical Physics education and training in most countries and their efforts to fulfil EFOMP recommendations. However, despite of this, there is still a wide variety of approaches within Europe, not only in the education and training programmes but also in professional practice. There is right now some European issues that can affect not only education and training but also the future of Medical Physics as a profession: 1. the harmonisation of the architecture of the European Higher Education System, arising from the "Bologna Declaration", for 2010, 2. the recently issued European directive: "Directive 2005/36/EC of the European Parliament and of the Council of 7 September 2005 on the recognition of professional qualifications". EFOMP is now challenged to make recommendations for education and training in Medical Physics, within the context of the current developments in the European Higher Education Area arising from "The Bologna Declaration", and with a view to facilitate the free movement of professionals within Europe, according to the new Directive.

Guidelines for education and training of medical physicists in radiotherapy. Recommendations from an ESTRO/EFOMP working group.

PURPOSE: To provide a guideline curriculum covering theoretical and practical aspects of education and training for medical physicists in radiotherapy within Europe. MATERIAL AND METHODS: Guidelines have been developed for the specialist theoretical knowledge and practical experience required to practice as a medical physicist in radiotherapy. It is assumed that the typical entrant into training will have a good initial degree in the physical sciences, therefore these guidelines also require that and are additional to it. National training programmes of medical physics, radiation physics and radiotherapy physics from a range of European countries and from North America were reviewed by an expert panel set up by the European Society of Therapeutic Radiology and Oncology (ESTRO) and the European Federation of Organisations for Medical Physics (EFOMP). A draft document prepared by this group was circulated, via the EFOMP infrastructure, among national professional medical physics societies in Europe for review and comment and was also discussed in an education session in the May 2003 EFOMP scientific meeting in Eindhoven. RESULTS: The resulting guideline curriculum for education and training of medical physicists in radiotherapy within Europe discusses the EFOMP terms, qualified medical physicist (QMP) and specialist medical physicist (SMP), and the group's view of the links to the EU (Directive 97/43) term, medical physics expert (MPE). The minimum level expected in each topic in the theoretical knowledge and practical experience sections is intended to bring trainees up to the requirements of a QMP. The responses from the circulation of the document to national societies and its discussion were either to agree its content, with no changes required, or to suggest changes, which were taken into account after consideration by the expert group. Following this the guidelines have been endorsed by the parent organisations. CONCLUSIONS: This new joint ESTRO/EFOMP European guideline curriculum is a first step to harmonise specialist training of medical physicists in radiotherapy within Europe. It provides a common framework for national medical physics societies to develop or benchmark their own curricula, but is also flexible enough to suit different situations of initial physics qualifications, medical physics training programmes, accreditation structures, etc. The responsibility for the implementation of these standards and guidelines will lie with the national training bodies and authorities.