7th ICHNO Abstract book

page 90 7 th ICHNO Conference International Conference on innovative approaches in Head and Neck Oncology 14 – 16 March 2019 Barcelona, Spain __________________________________________________________________________________________ 7th ICHNO

thyroid cancer patients who then will require a more intensified treatment approach. PO-169 The Phase I/II ACCEPT Trial: Cetuximab and IMRT with Carbon Ion Boost for Adenoid Cystic Carcinoma S. Adeberg 1 , A. Jensen 2 , S. Akbaba 1 , S. Katayama 1 , V. Verma 3 , D. Bernhardt 1 , A. Nikoghosyan 4 , A. Abollahi 1 , P. Plinkert 5 , S. Rieken 1 , M. Muenter 6 , D. Juergen 1 1 University Hospital Heidelberg, Department of Radiation Oncology, Heidelberg, Germany; 2 University Hospital Giessen, Department of Radiaton Oncology, Giessen, Germany; 3 Allegheny General Hospital, Department of Radiation Oncology, Pittsburgh, USA; 4 Helios Clinic Berlin-Buch, Department of Radiation Oncology, Berlin- Buch, Germany; 5 University Hospital Heidelberg, Department of Head and Neck Surgery, Heidelberg, Germany; 6 Katharinenhospital Stuttgart, Department of Radiation Oncology, Stuttgart, Germany carcinoma (ACC), Erbitux®, and ParticleTherapy (ACCEPT) phase I/II trial (NCT01192087) evaluated a combined-modality approach (concurrent cetuximab and intensity-modulated radiotherapy (IMRT) with carbon ion (CIRT) boost) for newly-diagnosed nonmetastatic head/neck ACC. Material and Methods Twenty-three patients with ACC were enrolled between June 2012 and June 2017 following initial diagnosis or postoperatively. All received a 400 mg/m² cetuximab loading dose a week before radiotherapy, followed by weekly 250 mg/m² doses starting on the first day of radiotherapy. The CIRT boost was 24 Gy (RBE) in 8 daily fractions, followed by IMRT (54 Gy). The primary endpoint was safety and feasibility (CTCAE grade ≥3 events). Secondary endpoints included local and distant relapses, disease-free survival (DFS), and overall survival (OS). Results Disease was most commonly in the paranasal sinuses (30%), palate (17%), and nasopharynx (17%). Nine (39%) patients underwent surgery (R1: 22%, R2: 78%). Median follow-up was 38.5 months. No patients experienced grade 4-5 events. Rates of grade 3 rash and radiation dermatitis were 17% and 22%, respectively. Grades 2 and 3 mucositis and dysgeusia occurred in 43% & 48% and 9% & 0%, respectively. Grades 2-3 dysphagia and xerostomia were present in 43% & 4% and 26% & 0%, respectively. At last follow-up, 5 (22%) patients experienced in-field relapse and 6 (26%) developed distant metastases. The three-year DFS was 67%, and median OS was 54 months. Conclusion Outcomes of this trial were satisfactory. Rates of grade 3 dermatitis and mucositis were comparatively high but are comparable to existing cetuximab+RT data. PO-170 First reported treatment results for adenoid cystic carcinoma (ACC) of the nasopharynx S. Akbaba 1 , D. Ahmed 1 , K. Lang 1 , T. Held 1 , M. Mattke 1 , K. Herfarth 1 , S. Rieken 1 , P. Plinkert 2 , J. Debus 1 , S. Adeberg 1 1 University Hospital Heidelberg, Radiation Oncology, Heidelberg, Germany; 2 University Hospital Heidelberg, Otorhinolaryngology- Head and Neck Surgery, Heidelberg, Germany Purpose or Objective Adenoid cystic carcinomas (ACC) of the nasopharynx are often diagnosed in locally advanced stages with skull base infiltration preventing complete resection in the majority Purpose or Objective The adenoid cystic

the defect and high pressure of CSF. This algorithm may pave the way to wider use of endonasal endoscopic corridors to the skull base, resulting in a remarkable decrease of surgical morbidity. PO-168 Prevalence of BRAF, RAS and RET/PTC gene mutations in aggressive well-differentiated thyroid cancers S. Suresh 1 , N.A. George 1 1 Regional Cancer Centre, Surgical Oncology, Thiruvananthapuram, India Purpose or Objective Thyroid cancer incidence has increased worldwide over the last three decades. The age-standardized incidence rate adjusted to world standard population for Thiruvananthapuram was 13 according to Globocan 2012 and PBCR 2012 data, which implies that the district was the eighth most affected region in the world. Usually following treatment, low-risk thyroid cancer patients are kept on thyroxine supplementation for a long time. Upto 20% patients may present with recurrence several years later. This is because of the aggressive nature of these cancers. Aggressiveness is described based on clinical and histocytologic criteria. The high incidence of thyroid cancers in our country, especially in the state of Kerala and the scarcity of previous studies to establish prognostic significance of gene mutations in predicting the aggressive nature of thyroid cancers from India prompted us to take up this study. The objectives were to study the prevalence of BRAF, RAS and RET/PTC gene mutations in histologically aggressive and clinically advanced well-differentiated thyroid cancers. Material and Methods This study was done on archival blocks of patients with thyroid cancers reported at the Regional Cancer Centre, Thiruvananthapuram during 2012-15 and who underwent complete panel of treatment based on institutional protocol (Total thyroidectomy with / without Radioiodine Ablation). Tumours showing aggressive features on histology and patients with high risk clinical features at initial presentation like extra-thyroidal spread, lymph node metastasis and advanced tumour stage were identified from medical case records. Paraffin blocks of the above patients were collected from the department of Pathology. DNA extracted from formalin-fixed paraffin embedded sections was subjected to PCR to amplify the gene of interest. Direct sequencing of PCR-amplified products was done to identify BRAF, RAS and RET/PTC gene mutations. Prognosis of various factors related to gene mutations was assessed using log-rank test and cox- regression model. Results BRAF mutation is the most common genetic alteration in thyroid cancer, occurring in about 65% of papillary thyroid cancers (PTCs) and an independent molecular prognostic marker in the risk evaluation and recurrence of thyroid cancers. There was significant correlation between BRAF mutation and lymph node metastasis in PTC in our study with a significant Positive Predictive Value and Negative Predictive Value of BRAF positivity for central compartment lymph node metastasis. Conclusion There is a high prevalence of BRAF, RAS and RET/PTC gene mutations in papillary thyroid cancers in Indian population as compared to previous studies done in the west. BRAF, RAS and RET/PTC mutations play a significant role in detecting aggressive behaviour in intermediate-risk