ESTRO 36 Abstract Book

S323 ESTRO 36 _______________________________________________________________________________________________

Conclusion Data about the impact of PET imaging in GTV definition in H&N cancers are conflicting although most studies evaluating both tumor and nodes GTV showed a reduced volume using PET. The used PET-delineation methodology seems to influence the results with larger differences (compared to CT-scan) by using VM. PO-0619 Comparison of a nanoString and RNA microarray gene signature predicting LRC after PORT-C in HNSCC S. Schmidt 1,2,3,4 , A. Linge 1,3,4,5,6 , A. Zwanenburg 1,3 , S. Leger 1,3 , F. Lohaus 1,3,5,6 , V. Gudziol 7 , A. Nowak 8 , I. Tinhofer 9,10 , V. Budach 9,10 , A. Sak 11,12 , M. Stuschke 11,12 , P. Balermpas 13,14 , C. Rödel 13,14 , A.L. Grosu 15,16 , A. Abdollahi 17,18,19,20,21 , J. Debus 17,18,19,20,22 , C. Belka 23,24 , S.E. Combs 23,25 , D. Mönnich 26,27 , D. Zips 26,27 , G.B. Baretton 3,28,29 , F. Buchholz 3,30 , M. Baumann 1,2,3,5,6 , M. Krause 1,2,3,5,6 , S. Löck 1,3,5 1 OncoRay – National Center for Radiation Research in Oncology, TU Dresden- Med. Faculty Carl Gustav Carus, Dresden, Germany 2 Helmholtz-Zentrum Dresden – Rossendorf, Institute of Radiooncology, Dresden, Germany 3 German Cancer Research Center - Heidelberg, DKTK partner site Dresden, Dresden, Germany 5 National Center for Tumor Diseases NCT, partner site Dresden, Dresden, Germany 6 TU Dresden - Med. Faculty Carl Gustav Carus, Department of Radiation Oncology, Dresden, Germany 7 TU Dresden - Med. Faculty Carl Gustav Carus, Department of Otorhinolaryngology, Dresden, Germany 8 TU Dresden - Med. Faculty Carl Gustav Carus, Department of Oral and Maxillofacial Surgery, Dresden, Germany 9 German Cancer Research Center - Heidelberg, DKTK partner site Berlin, Berlin, Germany 10 Charité University Hospital, Department of Radiooncology and Radiotherapy, Berlin, Germany 11 German Cancer Research Center - Heidelberg, DKTK partner site Essen, Essen, Germany 12 Medical Faculty- University of Duisburg-Essen, Department of Radiotherapy, Essen, Germany 13 German Cancer Research Center - Heidelberg, DKTK partner site Frankfurt, Frankfurt, Germany 14 Goethe-University Frankfurt, Department of Radiotherapy and Oncology, Frankfurt, Germany 15 German Cancer Research Center - Heidelberg, DKTK partner site Freiburg, Freiburg, Germany 16 University of Freiburg, Department of Radiation Oncology, Freiburg, Germany 17 German Cancer Research Center - Heidelberg, DKTK partner site Heidelberg, Heidelberg, Germany 18 Heidelberg Institute of Radiation Oncology HIRO- National Center for Radiation Research in Oncology NCRO, University of Heidelberg Medical School and German Cancer Research Center DKFZ, Heidelberg, Germany 19 Heidelberg Ion Therapy Center HIT, Department of Radiation Oncology- University of Heidelberg Medical School, Heidelberg, Germany 20 National Center for Tumor Diseases NCT, partner site Heidelberg, Heidelberg, Germany 21 University of Heidelberg Medical School and German Cancer Research Center DKFZ, Translational Radiation Oncology, Heidelberg, Germany 22 Clinical Cooperation Unit Radiation Oncology, University of Heidelberg Medical School and German Cancer Research Center DKFZ, Heidelberg, Germany 23 German Cancer Research Center - Heidelberg, DKTK partner site Munich, Munich, Germany 24 Ludwig-Maximilians-Universität, Department of Radiotherapy and Radiation Oncology, Munich, Germany 25 Technische Universität München, Department of Radiation Oncology, Munich, Germany

treatment.

PO-0618 Role of PET in radiotherapy planning of head and neck tumors: a systematic review M. Ferioli 1 , A. Farioli 2 , F. Cellini 3 , A. Arcelli 1,4 , I. Sandler 5 , S. Cilla 6 , F. Deodato 7 , G. Macchia 7 , S. Cammelli 1 , A. Guido 1 , F. Romani 8 , A. Angelini 8 , G. Compagnone 8 , F. Miccichè 3 , R. Frakulli 1 , M. Buwenge 1 , M. Marengo 8 , V. Valentini 3 , S. Fanti 5 , A.G. Morganti 1 1 University of Bologna, Radiation Oncology Center- Dept. of Experimental- Diagnostic and Specialty Medicine – DIMES, Bologna, Italy 2 S. Orsola-Malpighi Hospital- University of Bologna, Department of Medical and Surgical Sciences DIMEC, Bologna, Italy 3 Policlinico Universitario “A. Gemelli”- Catholic University of Sacred Heart, Department of Radiotherapy, Rome, Italy 4 Ospedale Bellaria, Radiotherapy Department, Bologna, Italy 5 S. Orsola-Malpighi Hospital- University of Bologna, Department of Nuclear Medicine, Bologna, Italy 6 Fondazione di Ricerca e Cura “Giovanni Paolo II”- Catholic University of Sacred Heart, Medical Physics Unit, Campobasso, Italy 7 Fondazione di Ricerca e Cura “Giovanni Paolo II”- Catholic University of Sacred Heart, Radiotherapy Unit, Campobasso, Italy 8 S'Orsola-Malpighi Hospital, Medical Physics Unit, Bologna, Italy Purpose or Objective Use of PET imaging has been proposed in radiotherapy (RT) treatment planning of locally advanced H&N tumors. Some studies showed that most local relapses occur in PET- positive volumes before RT. Therefore, the possibility to define the GTV using PET-imaging has been considered as an opportunity to reduce the irradiated volume allowing Organs at Risk sparing and thus dose-escalation. Some studies analyzed the volumetric differences between the GTV volume evaluated by CT versus PET imaging. Aim of this analysis was to systematically review the available From Pubmed database, a literature search ('PET” AND 'Radiotherapy Planning”) was performed using the PRISMA guidelines including published studies about GTV definition in H&N tumors using CT versus PET imaging. Reviews, editorials, letters and case reports were excluded. Only article published in English were considered. Results A total of 14 studies reporting data on GTV definition using both CT and PET imaging met the inclusion criteria. The median number of analyzed patients was 26 (range: 6-91). Eight studies included only patients with SCC H&N tumors. PET based GTV delineation was performed by manual contouring (visual method: VM) in 8 studies and by auto- contouring (AC) using 40-50% intensity level for 18F -FDG PET images in 4 studies. Seven studies reported PET-based GTV-T (primary tumor only), compared to CT-based GTV- T, being larger in 2 studies (1VM, 1 AC), smaller in 3 studies (3 VM), and not different in 2 studies (1 VM, 1 AC). Six studies reported PET-based GTV-N (nodal disease only), compared to CT-based GTV-N, being larger in 1 study (1VM), smaller in 1 study (1 AC), and not different in 4 studies (3 VM, 1 AC). Seven studies reported PET- based GTV-T+N (combined primary tumor plus nodal disease), compared to CT-based GTV-T+N, being smaller in 5 studies (4 VM, 1 AC) and not different in 2 studies (1 VM, 1 AC). In the evaluation of GTV-T+N, PET-based GTV showed a significant reduction in 1/2 AC study and in 4/5 VM studies. literature on this issue. Material and Methods