ESTRO 36 Abstract Book

S288 ESTRO 36 _______________________________________________________________________________________________

S.J.M. Habraken 1 , A.W. Sharfo 1 , J. Buijsen 2 , W.F.A.R. Verbakel 3 , C.J.A. Haasbeek 3 , M.C. Ollers 2 , G.H. Westerveld 4 , N. Van Wieringen 4 , O. Reerink 5 , E. Seravalli 5 , P.M. Braam 6 , M. Wendling 6 , T. Lacornerie 7 , X. Mirabel 7 , R. Weytjens 8 , L. Depuydt 8 , S. Lang 9 , O. Riesterer 9 , K. Haustermans 10 , T. Depuydt 10 , B.J.M. Heijmen 1 , A. Méndez Romero 1 1 Erasmus MC Cancer Institute, Department of Radiation Oncology, Rotterdam, The Netherlands 2 MAASTRO Clinic, Department of Radiation Oncology, Maastricht, The Netherlands 3 VU University Medical Center, Radiation Oncology, Amsterdam, The Netherlands 4 Academic Medical Center, Radiotherapy, Amsterdam, The Netherlands 5 University Medical Center Utrecht, Department of Radiotherapy, Utrecht, The Netherlands 6 Radboud University Medical Center, Radiation Oncology, Nijmegen, The Netherlands 7 Oscar Lambret Comprehensive Cancer Center, Academic Radiation Therapy Department, Lille, France 8 GZA Sint-Augustinus, Radiotherapy, Wilrijk, Belgium 9 University Hospital Zürich, Department of Radiation Oncology, Zürich, Switzerland 10 University Hospital Gasthuisberg, Radiation Oncology, Leuven, Belgium Purpose or Objective The TRENDY trial is an international multi-center phase II study in which patients with hepatocellular carcinoma (HCC) are randomized between transarterial chemoembolization in the standard arm and stereotactic body radiation therapy (SBRT) in the experimental arm. SBRT is delivered in six fractions with a total target dose of 48-54 Gy. An extensive QA program has been implemented, including prospective (prior to delivery) feedback on treatment plans, generated in the participating centers. For this feedback, the QA team uses a platform for automated treatment plan generation and planning CT-scans submitted by the centers. Here, we report on the first experiences. Material and Methods Based on the trial constraints and objectives, including a constraint on the NTCP for the healthy liver (NTCP ≤ 5%), fully automated plan generation for HCC has been implemented in a system for automatic prioritized multi- criteria optimization of deliverable VMAT plans (autoVMAT). Prior to treatment, participating centers send the contoured CT-scan of a new patient to the QA team. A plan is then automatically generated to be compared with the plan that was generated in the centers, using the common manual planning. Comparisons can result in improvements of the latter plan, which will be used clinically. The goal is to promote quality and uniformity of the SBRT treatment, and thereby, clinical outcome. Results AutoVMAT plans are compared to 19 manual treatment plans, 12 from a dummy run, 5 from a clinical pilot, and 2 from trial patients. Since target coverage is similar for all plans, we focus on OARs. Although some non-coplanar Cyberknife plans outperform the corresponding co-planar autoVMAT plan, for most patients, autoVMAT resulted in a superior plan, with an average NTCP reduction of 4.0%. (range: -25.4% to 0.5%, p = 0.013), a lower mean dose to the healthy liver (p < 0.01) and lower doses to gastrointestinal OARs (see figures). As significantly suboptimal plans are easily identified, this approach is well-suited for prospective feedback on treatment planning for individual patients.

NTCP of the liver minus GTV for autoVMAT plans (horizontal) and manual plans (vertical) for the same patients.

Gastrointestinal OAR doses for autoVMAT plans and manual plans. Conclusion Fully automated treatment planning has been implemented in the QA program of the randomized TRENDY trial for prospective plan QA (prior to plan delivery), and contributes to the objective evaluation of submitted treatment plans.

Proffered Papers: Patient safety and treatment outcome

OC-0542 Dysphagia, Odynophagia and Globulus in Patients Receiving RT for Spinal Cord Compression V. Gram 1 , M. Hemer 1 , A. Appelt 2 , H. Pappot 1 , P. Sjøgren 1 , L.S. Fog 1 1 Rigshospitalet, Department of Radiotherapy- Clinic of Oncology, København, Denmark 2 St James’s University Hospital, Leeds Institute of Cancer and Pathology- University of Leeds and Leeds Cancer Centre, Leeds, United Kingdom Purpose or Objective This study aimed at determining the incidence and association of dysphagia with esophageal dose and disease localization in patients receiving radiation therapy (RT) for spinal cord compression (SCC). Material and Methods This prospective study included thirty consecutive patients, who received 10 fractions of 3 Gy of RT for SCC at our clinic. Patients were irradiated using VMAT with daily CBCT. Patients were followed daily for 3 weeks, using the mBPI and ESAS questionnaires and weekly using the EORTC30 questionnaire; hereafter weekly using mBPI, ESAS and EORTC30 for 4 weeks, totaling 7 weeks. Patients were contacted by phone or personal interview. The incidence of dysphagia, odynophagia and globulus (collectively DOG) was determined. Since DOG typically