Abstract book - ESTRO meets Asia

S26 ESTRO meets Asia 2018

number of megavoltage machine was around 7 per million inhabitants. In an intermediate group of countries, including France, Spain and the United Kingdom, around 60% of the machines was capable of delivering IMRT and there were around 6 MV machines per million inhabitants. Especially in Eastern and Southern regions of Europe, the percentage of machine capable of delivering IMRT was only 40% and the number of machines per million only 3- 4. Another ESTRO-HERO study showed that availability of personnel throughout Europe had improved and was more in line with the recommendations from the QUARTS project, but also for personnel, important differences were noted between countries. The HERO project, which was launched in 2010, has the overall aim to develop a knowledge base and model for health economic evaluation of radiotherapy at the European level. As part of this also a cost-accounting program for radiotherapy studies has been developed and studies on cost-effectiveness and cost-utility are underway. SP-063 Where are we now and where are we heading? Y. Lievens 1 1 Ghent University Hospital, Radiation Oncology Ghent Belgium

anatomical changes. Recently, electronic portal imaging device (EPID)-based and log file-based QA approaches have been implemented clinically. The EPID-based QA approach is used to check both the isocenter dose and treatment reproducibility by comparing EPID portal images. In addition, it allows reconstruction of the dose delivered to the patient by means of a transmitted signal acquired in cine mode during the treatment session. The log file-based QA approach also enables evaluation of the dose distribution in the patient’s anatomy based on recorded values in the log files. In this lecture, I will describe the trend of QA approaches and weigh the pros and cons of the EPID- and log file-based QA approaches on the basis of our clinical experience. SP-066 Quality management in treatment delivery M. Coffey 1 1 Trinity College Dublin, Discipline of Radiation Therapy, Dublin, Ireland Abstract text The aim of treatment delivery is the accurate and safe delivery of the treatment as prescribed with minimal impact on the patient. There are several aspects to consider in this context concerning both radiation and no radiation factors. Meeting this aim is strongly influenced by the level of knowledge of the RTTs on the technical and patient related factors which is fundamental to accurate safe treatment delivery. Before considering individual patient treatment there are general factors that the RTT needs to check prior to starting treatment of patients. The RTT should have active involvement in the daily quality control of the treatment unit as they are ultimately responsible for its use. This may be verifying that certain checks have been carried out but also includes physically checking a range of parameters including laser alignment, interlocks, couch locking and validity of accessory devices used routinely and that impact on the quality of the treatment delivery. Non radiation aspects such as hygiene and infection control and accessory devices such as steps to mount and dismount the couch should be checked and monitored regularly. Clear accurate documentation of all checks should be completed and readily available at all times. For each individual patient the RTT must check the prescription and plan and whether any changes have been made and implemented. They must check whether the patient has any appointments or outstanding test results for review and ensure that everything is in place to proceed with the planned treatment. The RTT must check the patient identity using at least two parameters and must discuss with the patient their physical, psychological and social status to ensure that they are well enough to continue. .During the actual treatment the patient must be monitored at all times for signs of distress or movement and any verification images required must be acquired and reviewed in accordance with departmental protocol prior to proceeding. For a new patient all parameters must be checked and detailed information given to the patient on what to expect from treatment. Clear and unambiguous instructions on what to expect in terms of side effects and how they can be minimised must be provided and the patient given the opportunity to ask any questions that are relevant for them. Following treatment clear and detailed documentation must be completed. SP-067 Safe and rapid implementation of radiotherapy technologies and techniques: the RABBIT system A. Ralston 1 , J. Yuen 1 1 St George Public Hospital, Cancer Care Centre, Sydney- NSW, Australia

Abstract not received

Saturday 8 December 2018

Teaching lecture: Fractionation and overall time

SP-064 Fractionation and overall time E. Hau 1 1 Sydney West Radiation Oncology Netword, Radiation Oncology, Sydney, Australia

Abstract text This lecture will cover the rationale and the expected acute/late normal tissue effects as well as the effects on the tumour using conventional as well as altered fractionation. Data from clinical trials across multiple tumour sites including lung, head/neck, breast and prostate cancers will be used to illustrate the effect of changing dose per fraction and overall treatment time. SP-065 RT dosimetry yesterday, today and tomorrow M. Nakamura 1 1 Kyoto University, Department of Medical Physics, Kyoto, Japan Abstract text Patient-specific dosimetric quality assurance (QA) is required when conducting intensity-modulated radiation therapy or volumetric modulated arc therapy. This requires the use of a measurement device, such as an ionization chamber, radiochromic film, or an array detector, to verify treatment delivery prior to treatment. The results of such QA measurements are used to inform treatment practitioners of potential errors derived from the treatment plans and machine conditions that can be detected before treatment. Many studies have reported that variation in the inter- and intrafractional size and position of organs occurs during the course of treatment. Even if the dosimetric QA testing results meet institutional criteria, there is no guarantee that doses will be delivered as planned throughout the course of treatment, due to mechanical errors and Teaching lecture: Quality management