6th ICHNO Abstract Book

page 34 6 th ICHNO Conference International Conference on innovative approaches in Head and Neck Oncology 16 – 18 March 2017 Barcelona, Spain __________________________________________________________________________________________ 6th ICHNO

PO-069 Radiation Dose and Distribution Following Transoral Robotic Surgery of the Palatine Tonsil S. Naqvi 1 , J.Ferrell 2 , A. Blanco 3 , J.Bigcas 1 , K. Jain 1 , R. Karni 1 1 The University of Texas Health Science Center- Houston, Otorhinolaryngology- Head and Neck Surgery, Houston, USA 2 Oregon Health & Science University, Otorhinolaryngology- Head and Neck Surgery, Portland, USA 3 The University of Texas Health Science Center- Houston, Radiation Oncology, Houston, USA Purpose or Objective The improved survival of HPV-associated oropharynx cancer has stimulated an interest in new approaches which de-escalate radiotherapy and in turn decrease treatment-related morbidity while maintaining a high rate of disease control. New technologies for transoral surgery of the oropharynx have emerged as an opportunity for reducing traditional radiotherapy dose applied to the mucosal site. Unilateral radiotherapy has been described as a unique opportunity for decreasing radiotherapy dose delivered to the contralateral neck in early palatine tonsil cancer. Material and Methods Since 2010, our Tumor Board has embraced transoral surgery with selective neck dissection for tonsil cancer with the objective of decreasing radiotherapy dose and distribution. Herein we present our experience with twenty-seven consecutive tonsil cancer patients undergoing transoral robotic surgery, including demographics, TNM stage, p16 status, margin control, extracapsular spread, perineural and lymphovascular invasion, locoregional control and disease- free survival. Radiation dose and distribution are reported in light of changes in the treatment plan that result from successful surgical treatment of the tonsil and neck. Patients recommended for unilateral post- operative radiotherapy included those with 1.) Pathologic T1-2 staging 2.) No extension beyond the glossotonsillar sulcus or within 1 centimeter of the uvula 3.) Clear pathologic margins and 4.) Pathologic neck stage ≤ N2b. Results In this series, there was 100% disease-free survival with a median follow up of 30 months. The radiation records of 12 patients were available through a questionnaire to the radiation oncologists and review of radiotherapy treatment records. In two patients, no radiotherapy was given due to early stage disease with clear margins (T1-2, N0). De-escalation of 10Gy to the tonsil primary site was observed in 10/12 patients. 7/12 patients received unilateral radiotherapy to the cervical nodes. 3/12 patients received therapeutic-dose radiation to both sides The role of transoral surgery and neck dissection in the de- escalation of adjuvant therapy is highlighted. Transoral surgery may also help guide which patients are candidates for unilateral radiotherapy by providing pathologic staging of the neck and histologically-confirmed tumor mapping in the oropharynx. Our series, in aggregate with others, strongly supports a treatment paradigm which distinguishes early stage tonsil cancer from other cancers of the oropharynx and endorses unilateral radiotherapy in selected cases. PO-070 Conventional vs bifractionated radiotherapy innasopharyngeal cancer 10years followup of phase3 trial W. Siala 1 , N. Sellami 1 , N. Toumi 2 , M. Drira 3 , A. Ghorbel 3 , M. Frikha 2 , J. Daoud 1 of the neck. Conclusion

months; 1-year locoregional control was 35% and freedom from distant metastases was 30%. Surgery was statistically significant to locoregional control. None of the remaining analysed variables had influence on survival and locoregional control. Conclusion Our results have a lower than expected local control. Despite the small number of patients, surgery was the only factor with positive impact on locoregional control. New strategies are warranted to improve the outcome of this disease. PO-068 Head and neck cancer of unknown primary origin: a single institution experience N. Ferreira 1 , J. Silva 2 , E. Netto 3 , G. Marau 1 , M. Ferreira 2 , F. Santos 1 1 Instituto Português de Oncologia de Lisboa Francisco Gentil- EPE, Radiation Oncology, Lisboa, Portugal 2 Instituto Português de Oncologia de Lisboa Francisco Gentil- EPE, Medical Oncology, Lisboa, Portugal 3 NOVA Medical School UNL, Radiation Oncology, Lisboa, Portugal Purpose or Objective To analyse the outcomes, patterns of failure and toxicity in patients with head and neck cancer of unknown primary origin (HNCUP). Material and Methods A retrospective database was used to identify patients with HNCUP for which they received curative-intent radiotherapy in our institution between 2009 and 2014. The patient characteristics, treatment plans and late toxicity profiles were reviewed, and the survival rates were calculated using the Kaplan-Meier method. Results We found 28 patients, 23 men and 5 women, with a median age of 57.5 years (range 41-82), and a KPS of 70 or higher in 64% of these patients. All patients were staged as T0 after comprehensive workup evaluation. Two (7%) presented with stage N2a, 10 (36%) with stage N2b, 3 (7%) with stage N2c, and 13 (46%) with stage N3 disease. A total of 15 (54%) patients underwent up-front neck dissection. 23 (82%) patients received systemic chemotherapy in a combined-modality setting. All patients underwent RT, 6 3D-CRT and 22 IMRT. Generally, patients were treated with comprehensive nodal irradiation to the bilateral neck and mucosal axis (nasopharynx, oropharynx, hypopharynx and larynx). No patient received oral cavity mucosal irradiation. Median doses to gross disease were 69.96 Gy, 66 Gy to high-risk or postoperative areas, 60 Gy to the mucosal axis and 50-54 Gy to the lower risk node levels. With a median follow-up of 3.6 years for the surviving patients, the overall survival, disease-free survival, distant metastasis-free survival and locoregional control rates were 64%, 47%, 69% and 54% at 3 years, respectively. Only 3 patients developed distant metastasis with locoregional control. Nine (32%) patients had persistent neck disease from which two were N2b and seven, N3. Only two nodal recurrences occurred within the RT volume: one in a 54 Gy level and the other in a 60 Gy level. There was one probable mucosal failure (larynx) in the 8 patients in which the larynx was spared from radiation. 8 (29%) patients reported Grade 1 late xerostomia, 7 (25%) Grade 2, with no Grade 3 late xerostomia reported. Conclusion Our study showed lower than expected locoregional control and survival rates. The large proportion of patients presenting with N3 disease may explain the suboptimal results. There were no failures in the spared oral mucosa. RT with or without chemotherapy for HNCUP produced reasonable toxicity profile.