ESTRO 36 Abstract Book

S291 ESTRO 36 _______________________________________________________________________________________________

1 Aarhus University Hospital, Department of Medical Physics, Aarhus C, Denmark 2 Copenhagen University Hospital- Herlev, Department of Oncology, Herlev, Denmark 3 Odense University Hospital, Department of Oncology, Odense, Denmark 4 Aarhus University Hospital, Department of Oncology, Aarhus C, Denmark Purpose or Objective Large changes in bladder shape and size during a course of radiotherapy (RT) make adaptive RT (ART) appealing in the treatment of this tumour site. Patients with bladder cancer unfit for surgery and chemotherapy were treated in a multicentre phase II trial of daily plan selection with the primary aim of reducing gastro-intestinal (GI) morbidity. Acute and late morbidity is reported from the trial and the frequency of acute diarrhoea is compared to a previous cohort of similar patients treated with non- All 54 patients (median age 80 years) received 60 Gy in 30 fractions to the bladder; in 41 of the patients the pelvic lymph nodes were simultaneously treated to 48 Gy. Cone- beam CT (CBCT) image guidance was used for daily set-up and treatment was delivered by volumetric modulated arc therapy (VMAT). The first five fractions were delivered using large, population-based margins(non-ART: 20 mm sup and ant; 15 mm post; 10 mm lat and inf); the bladder contours from the CBCTs acquired during the first four daily treatment sessions were used to create a library of three plans, corresponding to a small, medium and large size bladder. From fraction six all patients were treated using daily online plan selection, where the smallest plan covering the bladder was selected prior to each treatment delivery. Morbidity scoring was performed at baseline, every second week during RT and two weeks as well as 3, 12 and 24 month after RT using CTCAE v. 4.0. The frequency of any grade 2 or higher GI morbidity was evaluated at treatment completion. Peak acute morbidity was assessed using the scorings until 3 months after RT and peak late morbidity was evaluated after 12 months of follow up. The frequency of peak acute diarrhoea was compared to the cohort treated with non-ART. Acute and late genito-urinary (GU) morbidity was also recorded. Median follow-up was 12 months. Results Frequency of use of small size plans was 46%, medium 25% and large 31%. The median volume ratio of PTV-ART vs. non-ART across the treatment course was 0.68 (range: 0.46-0.93 for individual patients). Any GI morbidity grade 2 or higher was reported by 11 patients (20%) at treatment completion and returned to baseline level at the 3 months follow-up. Peak acute grade 2 or higher diarrhoea was reported by 12 patients (22%). In the previous cohort of patients treated with non-ART, 15 (30%) reported grade 2 or higher diarrhoea. An expected increase in acute GU morbidity during RT was observed compared to baseline scoring, but primarily grade 1. Late GU morbidity was comparable to baseline. Conclusion Daily adaptive plan selection in RT of bladder cancer results in a considerable dose sparing of normal tissue. This phase II trial indicates that adaptive RT can be delivered with low risk of morbidity. adaptive RT (non-ART). Material and Methods

GA has multiple drawbacks for the young patient, his relatives and the RTTs. VLADI (Video Launching Applied during Irradiation) project’s aim is to replace the use of anesthesia with the projection of videos during treatment in order to reassure and distract the patient throughout the treatment procedure. Material and Methods Finding alternatives to general anesthesia in the treatment of children is of great interest. Hypnosis has been known to replace anesthesia during interventions in some hospitals. This technique is very interesting but it varies from patient to patient and it’s somewhat difficult to apply in children undergoing RT treatments. As a possible alternative, VLADI project was created. It consists of a small projector which projects multimedia content in the field of view of the child throughout the treatment procedure. At this stage, this device has been specifically designed for Tomotherapy® treatment units. This project was started in late 2014 in our RT department, and we have evaluated the impact of the project on the potential reduction of the use of GA for children between the ages of 1.5 and 6 years old). Results VLADI’s impact on the use of GA was evaluated by comparing 2 groups of children aged between 1.5-6 years old (n= 12): Group 1 (n=6) composed of pediatric patient treated in our RT department before the implementation of VLADI project and Group2 (n=6) composed of pediatric patient treated in our RT department after the implementation of VLADI project. Since we implemented the VLADI project, we’ve diminished the use of GA from 83.3% (Group1) to 33.3% (group 2) and we’ve reduced the number of anxiolytics given to patients. In total, 72.2% of the children benefited of this system instead of GA. Also before VLADI each RT treatment with GA took at least 1h, after its implementation this has been reduced to 15- 20min.

Conclusion The use of VLADI as an alternative to anesthesia represents a gain both at the level of patient care (less medication) but also on a workflow level. In our department, VLADI has almost completely replaced anesthesia resulting in reduced treatment times and reduction of stress for the young patients and their family. These first results on our pediatric patients underline the efficiency of the system and can even be extended to claustrophobic or stressed adult patients who would – without VLADI- require anxiolytics to undergo their treatment. OC-0547 Acute and late morbidity in a Phase II trial of adaptive radiotherapy for urinary bladder cancer A. Vestergaard 1 , L. Muren 1 , H. Lindberg 2 , L. Dysager 3 , K. Jakobsen 2 , H. Jensen 3 , J. Petersen 1 , U. Elstrøm 1 , A. Als 4 , M. Høyer 4