7th ICHNO Abstract book

page 34 7 th ICHNO Conference International Conference on innovative approaches in Head and Neck Oncology 14 – 16 March 2019 Barcelona, Spain __________________________________________________________________________________________ 7th ICHNO

During the treatment of nasopharyngeal carcinoma (NPC), the use of intensity modulated radiation therapy (IMRT) showed conform and homogenous dose distribution in target volumes. The IMRT involves the application of high dose gradient around these structures to spare organs at risk. Any volume variation implies a modification of the received doses. In this work, we proposed to evaluate these anatomical modifications during the IMRT of NPCs as well as its dosimetric implication. Material and Methods Twenty patients treated with IMRT for NPC were enrolled in this study. For each patient, a second dosimetric CTwas performed at a dose of 38 Gy and then was fused with the initial planning scanner. Manual contouring of the macroscopic tumor volumes (GTV T and N) and the planning target volumes (PTV70, 60 and 54) were done in the second CT. We recorded the volumes of the different structures, D98%, the conformity and the homogeneity indexes for each PTV from the two CTs. Volume percent changes were calculated. Statistical means differences were calculated using Wilcoxon signed-rank’test andSPSS 20 softwarewas used for data analysis. Results We observed a significant reduction in tumor volumes, with values of 58.2% for the GTV N (p<10¯³) and 29.22% for the GTV T (p<10¯³). This behavior was accompanied by a significant decrease in the D98% for the 3 PTVs, with a values of 2.11 Gy for PTV 50 (p = 0.004), 1.21 Gy for PTV 60 (p = 0.014) and 2.6 Gy for PTV 70 (p = 0.001). In addition, we observed a significant reduction in the conformity index, with values of 0.006 for PTV 50 (p = 0.008), 0.013 for PTV 60 (p = 0.011) and 0.03 for PTV 70 (p = 0.001). Moreover, results showed a significant increase of the homogeneity index for PTV 50 (+0.053, p = 0.004), however no significant difference was observed for PTV 60 (+ 0.019, p = 0.052) and for PTV 70 (+0.016, p = 0.052). Conclusion The reduction in tumor volume (T and N) during the IMRT of NPCs was accompanied by deterioration of the dosimetric coverage for the different target volumes. It seems that a careful adaptation of the treatment plan should be considered during therapy. PO-065 Do comorbidities affect survival in head and neck cancer treated with Cetuximab and Radiotherapy? G. Fanetti 1 , C. Gobitti 1 , E. Minatel 1 , A. Revelant 1 , A. Drigo 2 , P. Chiovati 2 , C. Cappelletto 2 , S. Steffanini 1 , G. Franchin 1 1 IRCCS Centro di Riferimento Oncologico CRO National Cancer Institute, Division of Radiation Oncology, Aviano, Italy; 2 IRCCS Centro di Riferimento Oncologico CRO National Cancer Institute, Division of Medical Physics, Aviano, Italy Purpose or Objective Radiotherapy (RT) with concurrent high-dose Cisplatin (DDP) represents the gold standard for locally advanced head and neck squamous cell carcinoma. Intensity Modulated RT (IMRT) is a modern option of RT with improved respect of organ at risk, consequently with better tolerability. Age, general conditions and comorbidities can contraindicate this association in at least 20% of patients. Cetuximab (Cet) is a chimeric mouse IgG1 monoclonal anti-Epidermal Growth Factor Receptor (EGFR) antibody and has been employed in association to radiotherapy in patients unfit for DDP. The aim of the present study is to assess the oncologic outcome and the toxicity as well as the role of comorbidity on survival in

Otolaryngology, Pordenone, Italy; 6 IRCCS Centro di Riferimento Oncologico CRO National Cancer Institute, Division of Nuclear Medicine, Aviano, Italy Purpose or Objective To evaluate the oncologic outcome in term of survival and organ function preservation as well as toxicity in patients with locally advanced Oropharyngeal Cancer treated with Induction Chemotherapy (IC) followed by Intensity Modulated Radiotherapy (IMRT). Material and Methods The institutional organ preservation protocol consists in IC for 3 cycles of Docetaxel + Cisplatin + Fluorouracil (TPF scheme) followed by definitive IMRT for locally advanced OPC . Target delineation is performed with the guidance of pre-IC PET/CT. Total dose of IMRT delivered is 7095 cGy in 33 fractions. After treatment, response is evaluated with PET/CT and follow up is performed every 3 months the first 2 years, every 4 months the 3 rd year and every 6 months the 4 th and 5 th years. After the 5 th year, follow up is yearly. Savage pharyngolaryngectomy (SP) was performed in case of local recurrence. Toxicity is evaluated at each follow up and scored according to CTCAE terminology. Results We conducted a retrospective analysis of 53 consecutive pts treated at Centro di Riferimento Oncologico in Aviano between January 2010 and June 2017. Median age was 61 years and 42 (79%) pts were male. Initial TNM stage was IVA and IVB in 43 (81%) and 10 (19%) pts, respectively. HPV status was available in 49 pts and in 30 (57%) pts was positive. Median follow up was 28.8 months. Three years- relapse free (RFS) and overall survival (OS) were 68% and 79%, respectively (fig. 1). Four patients (8%) underwent SP for local relapse after a median time of 7 months. Late toxicity was mild. Only one patient needed feeding tube after SP and died 7 months later for progressive disease. No other >G2 toxicities were recorded during the follow up.

Conclusion In our cohort IC followed by IMRT was well tolerated and showed low rate of salvage surgery for local recurrences. RFS and OS were considerable and the toxicity profile was favourable. Further prospective analysis and randomized controlled trials on larger cohorts are needed to investigate the sequential approach in locally advanced OPC. PO-064 Changes in target volumes and dosimetric impact during the IMRT treatment of NPC H. Daoud 1 , M. Wafa 1 , F. Leila 1 , F. Nejla 1 , S. Wicem 1 , D. Jamel 1 1 Hbib Bourguiba Hospital, Radiotherapy, Sfax, Tunisia

Purpose or Objective