ESTRO38 Congress Report

RTT

1. Implementation of plan of the day adaptive radiotherapy: Compliance to guidelines (E38-1524) Amanda Webster 1 , Shaista Hafeez 2 , Emma Hall 2 , Vibeke N Hansen 3 , Helen McNair 2,4 , Rebecca Lewis 2 , Huddart Robert 2 1 National Radiotherapy Trials Quality Assurance (RTTQA), Mount Vernon Cancer Centre, London, United Kingdom, 2 The Institute of Cancer Research, 15 Cotswold Road, Sutton- SM2 5NG, United Kingdom, 3 Laboratory of Radiation Physics, Odense University Hospital, Odense, Denmark, 4 The Royal Marsden, The Royal Marsden, Downs Road- Sutton, United Kingdom

Context of the study The bladder is a dynamic organ, naturally changing in size and shape. Bladder filling andmovement canmake the organ a challenging target to treat with high doses of radiation. The RAIDER study adopts an adaptive radiotherapy approach, accounting for this deformation by creating 3 personalised radiotherapy plans: small, medium, and large. Using daily cone beam computed tomography (CBCT) the size and shape of the bladder is reviewed online and the most appropriate plan of the day (PoD) is selected by a pair of Therapeutic Radiographers (RTTs). A PoD approach is relatively new; with only 11/33 UK radiotherapy centres participating in RAIDER having previous PoD experience. We hypothesized that a rigorous pre-trial and on-trial Quality Assurance (QA) programme would be required to support RTTs in implementing this practice, and to enable them to be guideline compliant in their PoD selections. We further hypothesized we would require a strategy to sustain compliance. Overview of abstract In thismulticentre study, we aimed to determine the guideline compliance of RTT led online plan selection with offline plan selection of RTTQA reviewers. 439 CBCTs were initially evaluated, PoD selections were categorised and deviations from guidelines were assessed. As a consequence of this analysis, the PoD selection guidance and QA programme were revised to include: 1. Updated trial documentation, detailing plan selection steps 2. Formal PoD evaluation reports for all centres 3. An interactive workshop with RTTs Following updated guidance, a further 102 CBCTs were assessed for guideline compliance. What were the three main findings of your research: 318/439 (72%) PoD selections were guideline compliant. In the non-guideline compliant cases, the PoD selections by RTTQA were smaller in 87% and larger in 3%. In 10% of cases, the action taken would have been different e.g. remove the patient from treatment couch. Compliance was greater in the 32 fraction cohort, in centres with no previous PoD experience, in centres which previously employed weekly CBCTs for bladder patients, and for plan selections made in 2017 (Table 1). 4. A plan selection presentation 5. One-to-one training sessions

Following the revision of the QA programme, 98/102 (96%) plan selections were guideline compliant. What impact could your research have? Our work enforces the importance of a thorough educational and QA programme, when delivering novel radiotherapy techniques. Non-compliance was towards selecting larger plans, suggesting RTTs default to a ‘safe’ selection and require support making the ‘optimal’ choice. The results emphasise the efficacy of real-time monitoring of such training and adjusting as necessary. This research not only has implications for RTT education, but potentially, for the incidence of acute and late toxicity and the long-termoutcomes following adaptive radiotherapy. RTTQA provides independent, centrally co-ordinated QA for clinical trials with a radiotherapy component. This work also highlights the importance of the RTTQA group in the delivery of high-quality trials in the UK. Is this research indicative of a bigger trend in oncology? In this era of personalised radiotherapy, a rigorous QA programme and education is essential to ensure that these novel radiotherapy techniques are delivered optimally; this allows us to achieve the best possible outcome for the patient. RTTs are at the forefront of these novel techniques and theymust be empowered to act on radiotherapy delivery queries as they arise on-set. Education, feedback and audit of PoD selections should be considered as part of routine practice to ensure that high standards are maintained. With the emergence of real-time adaptive planning and treatment delivery e.g. usingMRLinacs, the approach taken, framework and skills learned from this study will be valuable when implementing adaptive techniques in clinical practice

RTT | Congress report

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