ESTRO 2021 Abstract Book

S763

ESTRO 2021

age- and gender-adjusted general population. The fact that elderly patients with HPV-associated HNSCC have significantly superior QoL values than their HPV-negative counterparts should be taken into account in treatment de-escalation considerations for this population.

PD-0922 Neoadjuvant Chemotherapy, Radiotherapy and Interferon-β in Paediatric Nasopharyngeal Cancers S. Kamer 1 , M. Öztürk 1 , E. Ataseven 2 , H. Öniz 3 , B. Kadıoglu 4 , B. Balcı 1 , D. Kizmazoglu 3 , M. Kantar 2 , Y. ANACAK 1 1 Ege University, Radiation Oncology, IZMIR, Turkey; 2 Ege University, Pediatric Oncology, IZMIR, Turkey; 3 Tepecik Childrens Hospital, Pediatric Oncology, IZMIR, Turkey; 4 Behcet Uz Childrens Hospital, Pediatric Oncology, IZMIR, Turkey Purpose or Objective Nasopharyngeal cancer (NPC)'s occurrence in a child is a rare entity and constitutes less than 1% of all cancers among children. The management of NPC in children is usually adapted from the adults . However, those children with NPC are still growing and extreme care should be taken to reduce the toxicity of the treatment. Turkey is a Mediterranean country representing an intermediate incidence of NPC. In this study, we present the treatment results of 49 pediatric patients whom were treated with neoadjuvant chemotherapy (CT) followed by radiotherapy (XRT) in a single center. Materials and Methods From January 2000 and December 2018, 49 children having a diagnosis of NPC were treated with neoadjuvant CT followed by external irradiation. The median age of the patients was 14 (range: 9-18), and the male to female ratio was 1.8. Histology was keratinizing undifferentiated carcinoma (Type-2) in 15 and non- keratinizing undifferentiated carcinoma (Type-3) in 34. Stage distribution was Stage-II 3 patients (6%), Stage- III 17 (35%) and Stage-IV 29 (59%). Initial distant metastases were detected in 9 cases. All patients received 3-4 cycles platinum-based neoadjuvant CT at every 3 weeks, where cisplatin/5-FU was the most common combination. XRT started 3-4 weeks after the last cycle of CT. XRT volumes always included the nasopharynx, parapharyngeal nodes, involved nodes of the neck and uninvolved nodes of the neck having high risk of spread. XRT was planned ad 3-D conformal treatment until 2012 and IMRT afterwards. Radiation doses were median 66 Gy (59-72) for CTV-tumor, 60 Gy (48-70) for CTV-N+ and 50 Gy (45-66) for CTV-N-. Daily subcutaneous amifostine injections was administered to 26 (53%) patients for radioprotection of the salivary glands. After the completion of XRT all patients received 6 months of recombinant IFN-β. Results Local-regional treatment response after chemoradiotherapy was as follows: CR in 46 cases (93.9%), PR in 3 (6.1%). After a median follow-up of 6.2 years, one patient experienced loco-regional recurrence after complete response and salvage radiochemotherapy was applied. 9 patients developed distant metastases- all were at lungs and bones; 5-y and 10-y DFS were 84.0% and 76.7%. 8 patients died of progressive disease; 5-y and 10-y OS were 83.5% and 78.8%. Late-effects were as follows: xerostomia in 32 patients (65.3%: G1-2 23 pts; G3-4 9 pts), neck fibrosis in 22 patients (44.9%: G1-2 20 pts, G3-4 2 pts), hypothyroidism in 18 (36.7%), teeth disorders in 24 (49%), trismus in 9 (18.4%) and autotoxicity 5/38 (13.1%). The rate of xerostomia was lower among patients who received amifostine (12/26 vs 19/23 – p<0.05). Conclusion Neoadjuvant platinum-based CT followed by XRT and maintenance IFN-B is an effective treatment for childhood NPC. CR is higher than 90%, locoregional recurrence is extremely low and survival is higher than 80%. Late effects are acceptable at those high radiation doses; however, amifostine may further reduce the late toxicity. C. Chargari 1 , C. Haie-Meder 1 , S. Espenel 1 , M. Ben-Arush 2 , S. Bolle 1 , A. Borjesson 3 , M. Cesen 4 , A. Costa Lago 5 , A. Desfachelles 6 , B. De Moerloose 7 , D. Valck 8 , N. Dos Reis Farinha 9 , N. Francotte 10 , H. Glosli 11 , G. Guillen Burrieza 12 , S. Helfre 13 , S. Irtan 14 , A. Kattamis 15 , A. Lacerda 16 , A. Levy 1 , L. Lyngsie 17 , L. Mansuy 18 , E. Mascard 19 , W. Mlynarski 20 , D. Orbach 21 , C. Owens 22 , P. Philippe-Chomette 23 , A. Peek 24 , B. Pizer 25 , C. Pluchart 26 , A.G. Rognlien 11 , A. Rome 27 , S. Sarnacki 28 , A. Safwat 29 , A. Schiavetti 30 , J. Serre 31 , C. Verite 32 , N. Von der Weid 33 , P. Wendtland 34 , M. Wysocki 35 , D. Valteau-Couanet 36 , E. Deutsch 1 , V. Minard-Colin 36 , H. Martelli 37 , F. Guérin 37 1 Gustave Roussy Cancer Campus, Radiation Oncology, Villejuif, France; 2 Ruth Rappaport children’s hospital, Pediatric Oncology, Haifa, Israel; 3 Lund University Hospital, Department of Pediatric Surgery, Lund, Sweden; 4 University Childrens Hospital Ljubljana, Pediatric Oncology, Ljubjiana, Slovenia; 5 Centro Hospitalar Universitário de São João, Radiation Oncology Department, Porto, Portugal; 6 Centre Oscar Lambret, Pediatric Oncology, Lille, France; 7 Ghent University Hospital , Department of Pediatric Hemato-Oncology , Ghent, Belgium; 8 Hôpital Universitaire des Enfants Reine Fabiola, Pediatric Oncology, Brussels , Belgium; 9 Centro Hospitalar Universitário de São João, Pediatric Oncology Department, Porto, Portugal; 10 SUHOPL Service Interhospitalier Universitaire d'Hématologie et d'Oncologie Pédiatrique Liégeois, Pediatric Oncology, Liège, Belgium; 11 Oslo University Hospital, Division of Paediatric and Adolescent Medicine, Oslo, Norway; 12 Hospital Infantil Universitari Vall d’Hebron, Pediatric Oncology, Barcelona, Spain; 13 Institut Curie, Radiation Oncology, Paris, France; 14 Pediatric Oncology, Centre Hospitalier Universitaire Armand Trousseau, Paris, France; 15 Sophia' Children's Hospital Papadiamantopoulou and Levadias, Division of Pediatric Hematology-Oncology, Athens, Greece; 16 Instituto Portugues de Oncologia de Lisboa Francisco gentil, Pediatric Oncology, Lisboa, Portugal; 17 University Hospital Rigshospitalet, Department of Pediatrics and Adolescent Medicine, Coppenhaguen, Denmark; 18 Centre Hospitalier Universitaire de Nancy, Pediatric Oncology, Nancy, France; 19 Centre Hospitalier Universitaire Necker, Pediatric surgery, Paris, France; 20 Medical University of Lodz, Department of Pediatrics, Oncology & Hematology, Lodz, Poland; 21 institut Curie, SIREDO Oncology Center (Care, Innovation and Research for Children, Adolescents and Young Adults with Cancer), Paris, France; 22 National Pediatric Oncology Unit, Our Lady's Children's Hospital, Pediatric Oncology, Dublin, Ireland; PD-0923 Increasing access to highly specialized radiation treatments: the example of pediatric brachytherapy