Harry Delis

Quality control in cone-beam computed tomography (CBCT) EFOMP-ESTRO-IAEA protocol (summary report)

The aim of the guideline presented in this article is to unify the test parameters for image quality evaluation and radiation output in all types of cone-beam computed tomography (CBCT) systems. The applications of CBCT spread over dental and interventional radiology, guided surgery and radiotherapy. The chosen tests provide the means to objectively evaluate the performance and monitor the constancy of the imaging chain. Experience from all involved associations has been collected to achieve a consensus that is rigorous and helpful for the practice. The guideline recommends to assess image quality in terms of uniformity, geometrical precision, voxel density values (or Hounsfield units where available), noise, low contrast resolution and spatial resolution measurements. These tests usually require the use of a phantom and evaluation software. Radiation output can be determined with a kerma-area product meter attached to the tube case. Alternatively, a solid state dosimeter attached to the flat panel and a simple geometric relationship can be used to calculate the dose to the isocentre. Summary tables including action levels and recommended frequencies for each test, as well as relevant references, are provided. If the radiation output or image quality deviates from expected values, or exceeds documented action levels for a given system, a more in depth system analysis (using conventional tests) and corrective maintenance work may be required.

Moving beyond quality control in diagnostic radiology and the role of the clinically qualified medical physicist

Quality control (QC), according to ISO definitions, represents the most basic level of quality. It is considered to be the snapshot of the performance or the characteristics of a product or service, in order to verify that it complies with the requirements. Although it is usually believed that the role of medical physicists in Diagnostic Radiology is QC, this, not only limits the contribution of medical physicists, but is also no longer adequate to meet the needs of Diagnostic Radiology in terms of Quality. In order to assure quality practices more organized activities and efforts are required in the modern era of diagnostic radiology. The complete system of QC is just one element of a comprehensive quality assurance (QA) program that aims at ensuring that the requirements of quality of a product or service will consistently be fulfilled. A comprehensive Quality system, starts even before the procurement of any equipment, as the need analysis and the development of specifications are important components under the QA framework. Further expanding this framework of QA, a comprehensive Quality Management System can provide additional benefits to a Diagnostic Radiology service. Harmonized policies and procedures and elements such as mission statement or job descriptions can provide clarity and consistency in the services provided, enhancing the outcome and representing a solid platform for quality improvement. The International Atomic Energy Agency (IAEA) promotes this comprehensive quality approach in diagnostic imaging and especially supports the field of comprehensive clinical audits as a tool for quality improvement.

Evaluation of the Impact of an International Master of Advanced Studies in Medical Physics

The Master of advanced studies in Medical Physics (MMP) has been jointly organized since 2014 by the International Centre for Theoretical Physics (ICTP) and Trieste University and supported by the International Atomic Energy Agency (IAEA), through the work of the Dosimetry and Medical Radiation Physics Section (DMRP), Division of Human Health (NAHU) and the IAEA Technical Cooperation Programme. The MMP, offers one academic year of theoretical classes followed by one year of structured clinical training in hospitals. It aims at addressing the scarcity of formal education and training schemes for medical physics studies, through an internationally harmonized programme that provides graduates with an academic knowledge and practical skills and competencies, to effectively practice medical physics once back to their home countries and Regions. Adequate academic education and structured clinical training of medical physicists play an important role in ensuring the safe and effective use of nuclear technologies in the diagnosis and treatment of patients. To evaluate the impact of the MMP, an online survey was developed and distributed to the graduates of the first two cycles of the programme, in March 2017, considering different aspects contributing to the overall fulfilment of the MMP aims. Criteria comprised: the activity of the graduates before and after the MMP, return rate to their home country and work activities performed after the degree. Specific feedback was also analysed about the MMP programme. The analysis of the 22 received answers (85% of all graduates at the time of the survey) is presented in this article.

Improvement of early detection of breast cancer through collaborative multi-country efforts: Medical physics component

PURPOSEnThe International Atomic Energy Agency (IAEA) through a Coordinated Research Project on Enhancing Capacity for Early Detection and Diagnosis of Breast Cancer through Imaging, brought together a group of mammography radiologists, medical physicists and radiographers; to investigate current practices and improve procedures for the early detection of breast cancer by strengthening both the clinical and medical physics components. This paper addresses the medical physics component.nnnMETHODSnThe countries that participated in the CRP were Bosnia and Herzegovina, Costa Rica, Egypt, India, Kenya, the Frmr. Yug. Rep. of Macedonia, Mexico, Nigeria, Pakistan, Philippines, Slovenia, Turkey, Uganda, United Kingdom and Zambia. Ten institutions participated using IAEA quality control protocols in 9 digital and 3 analogue mammography equipment. A spreadsheet for data collection was generated and distributed. Evaluation of image quality was done using TOR MAX and DMAM2 Gold phantoms.nnnRESULTSnQC results for analogue equipment showed satisfactory results. QC tests performed on digital systems showed that improvements needed to be implemented, especially in thickness accuracy, signal difference to noise ratio (SDNR) values for achievable levels, uniformity and modulation transfer function (MTF). Mean glandular dose (MGD) was below international recommended levels for patient radiation protection. Evaluation of image quality by phantoms also indicated the need for improvement.nnnCONCLUSIONSnCommon activities facilitated improvement in mammography practice, including training of medical physicists in QC programs and infrastructure was improved and strengthened; networking among medical physicists and radiologists took place and was maintained over time. IAEA QC protocols provided a uniformed approach to QC measurements.

1st European Congress of Medical Physics September 1–4, 2016; Medical Physics innovation and vision within Europe and beyond

Medical Physics is the scientific healthcare profession concerned with the application of the concepts and methods of physics in medicine. The European Federation of Organisations for Medical Physics (EFOMP) acts as the umbrella organization for European Medical Physics societies. Due to the rapid advancements in related scientific fields, medical physicists must have continuous education through workshops, training courses, conferences, and congresses during their professional life. The latest developments related to this increasingly significant medical speciality were presented during the 1st European Congress of Medical Physics 2016, held in Athens, September 1-4, 2016, organized by EFOMP, hosted by the Hellenic Association of Medical Physicists (HAMP), and summarized in the current volume.

Comparison of pencil-type ionization chamber calibration results and methods between dosimetry laboratories

A comparison of calibration results and procedures in terms of air kerma length product, PKL, and air kerma, K, was conducted between eight dosimetry laboratories. A pencil-type ionization chamber (IC), generally used for computed tomography dose measurements, was calibrated according to three calibration methods, while its residual signal and other characteristics (sensitivity profile, active length) were assessed. The results showed that the partial irradiation method is the preferred method for the pencil-type IC calibration in terms of PKL and it could be applied by the calibration laboratories successfully. Most of the participating laboratories achieved high level of agreement (>99%) for both dosimetry quantities (PKL and K). Estimated relative standard uncertainties of comparison results vary among laboratories from 0.34% to 2.32% depending on the quantity, beam quality and calibration method applied. Detailed analysis of the assigned uncertainties have been presented and discussed.