ESTRO 36 Abstract Book

S568 ESTRO 36 2017 _______________________________________________________________________________________________

cancer.

significant determinant of long term quality of life. We present early swallow outcomes in the first 15 patients. Material and Methods Patients with ≥T2, HPV-negative or high-risk HPV-positive disease, suitable for radical treatment with neo-adjuvant chemotherapy and chemo-IMRT, are eligible. Swallow measures are taken at 3 time points: at baseline, at 3 and 12 months post treatment. The Performance Status Scale - Normalcy of Diet subset (PSS – NoD) is based on the patient’s reported current diet. The Penetration- Aspiration scale (PAS) is scored from presentation on videofluoroscopy (VF). Results Fifteen patients (14-male, 1-female; mean age-61, range 49-71) were treated April’14-March’16, across two centres (median follow-up 10 months, range 4-26 months. All patients had a baseline assessment: On the PSS - NoD 73% (n=11) scored 100 (full diet, no restrictions), 27% (n=4) scored 50 (soft chewable foods). On the PAS 60% (n=9) scored 1 (material does not enter the airway), 27% (n=4) scored 2 (material enters the airway, remains above the vocal folds and is ejected from the airway), 13% (n=2) scored 8 (material enters the airway, passes below the vocal folds and no effort is made to eject). Fourteen patients were assessed at 3 months post- treatment (one declined): On the PSS - NoD 14% (n=2) scored 100 (full diet, no restrictions), 50% (n=7) scored 50 (soft chewable foods), 21% (n=3) scored 40 (soft foods requiring no chewing), 7% (n=1) scored 30 (pureed foods) and 7% (n=1) scored 20 (warm and cold liquids). On the PAS 7% (n=1) scored 1 (Material does not enter the airway), 14% (n=2) scored 2 (Material enters the airway, remains above the vocal folds and is ejected from the airway), 7% (n=1) scored 6 (Material enters the airway, passes below the vocal folds and is ejected into the larynx or out of the airway, 7% (n=1) scored 7 (Material enters the airway, passes below the vocal folds and is not ejected from the trachea despite effort) 64% (n=9) scored 8 (Material enters the airway, passes below the vocal folds and no effort is made to eject). No patient was nil oral at 3 month follow – up and no patient reported a history of chest infections. Conclusion VF assessment of swallow following PET/CT-guided selective dose escalation demonstrates deterioration of swallow status at 3 months. However, clinical significance is yet to be determined. 12 month post-treatment swallow measures are currently being taken. EP-1037 Chronic radiation-associated dysphagia (RAD) after curative reirradiation in head and neck cancer L. Gutierrez Bayard 1 , M. Salas Buzón 1 , E. Porras Alonso 2 , S. Garduño Sánchez 1 , M. Macias 1 , L. Ingunza Barón 1 , E. Gonzalez Calvo 1 , I. Villanego Beltran 1 , V. Diaz Diaz 1 1 Hospital Universitario Puerta del Mar, Radiation Oncology, Cadiz, Spain 2 Hospital Universitario Puerto Real, Otorrinilaringology, Puerto Real, Spain Purpose or Objective Chronic radiation-associated dysphagia (RAD) is a complex toxicity. The Total Dysphagia Risk Score (TDRS) was developed to predict which patients are most at risk to develop grade ≥ 2 dysphagia at 6 months following radiotherapy (RT). The mylo/geniohyoid complex (MHM) V69 ( the volume receiving ≥69 Gy), , and superior constrictor muscle (SPC V70), especially in older patients (>62-years), were associated with chronic-RAD.Acute during the course of RT are strong prognostic factors for late dysphagia. There is no effective treatment to reverse chronic-RAD in longterm survivors; and intensive and costly therapies are required for incremental gains in functionality.

EP-1035 Dose-volume analysis of the hypoglossal nerve and its correlation with Dysarthria-Dysphagia Syndrome F. Chen 1 , R. Rer 2 1 Chenzhou No.1 People's hospital, radiation oncology, chenzhou, China 2 Yee-Ren Hospital, Radiation Oncology, taibei, Chinese Taipei Purpose or Objective Cranial nerve palsy is a radiotherapy-related late toxicity in nasopharyngeal cancer patients after radiotherapy, and the glossopharyngeal, vagus and hypoglossasl nerve are the most commonly damaged, causing speech and swallowing handicap. Damage to the larynx or pharyngeal constrictor muscles have been mentioned as the cause of swallowing disorder in head & neck cancer patients after radiotherapy. We hypothesize that direct radiation damage to the nerve is the etiology of hypoglossal palsy and the subsequent dysarthria-dysphagia syndrome. This study aims to test our hypothesis using dosimetric data. Material and Methods Twelve Nasopharyngeal Cancer Patients were enrolled in this study, with three patients for each stage. They all received IMRT technique. We gave 70 Gy to the nasopharynx and positive neck lymph node, 60 Gy to the high-risk neck and 50 Gy to the low-risk neck. We contoured the larynx and the constrictor muscles including superior, middle, inferior, cricopharyngeus, and the proximal esophagus. Hypoglossal nerve was also delineated and divided into cisternal, intracanalicular, carotid, horizontal, and lingual part. The Maximal Dose, Minimal Dose, Mean Dose, V50, V55, V60, V65 and V70 were derived using Varian Eclipse planning system, respectively. Results Of the constrictor muscle, the superior always had the highest dose in all stages. V65 of the superior constrictor muscle was 60%±15%, 100%±20%, 100%±21.6% and 78.4%±14.3% for stage I, II, III & IV, respectively. V60 of the larynx was 2.75%±0.65%, 11.7%±0.3% ， 1 2.3%±0.6% ， 15.2%±1.8% for stage I, II, III & IV, respectively. For hypoglossal nerve, the intracanalicular and the carotid segment had the highest dose. V65 of the intracanalicular segment were 43%±12.5%, 42%±6.2%, 48%±22% and 80%±14%, for stage I, II, III, and IV, respectively. It was 53%±12.5%,81%±2%,82%±7% and 86%±14%, for the carotid segment. Conclusion Hypoglossal nerve palsy and the subsequent Dysarthria- Dysphagia Syndrome in nasopharyngeal cancer patients may be related to the high dose of the carotid segment of the hypoglossal nerve. Constrictor muscle and larynx are less likely to be the underlying etiology according to dose-volume data. EP-1036 18F-FDG-PET in Guiding Dose-painting with IMRT in Oropharyngeal Tumours (FiGaRO) – Swallow Results C. Doughty 1 , J. Dunton 1 , A. Michaelidou 2 , M. Lei 2 , T. Guerrero Urbano 2 1 Guy's and St.Thomas' Hospital NHS Foundation Trust, Speech and Language Therapy, LONDON, United Kingdom 2 Guy's and St.Thomas' Hospital NHS Foundation Trust, Radiotherapy, LONDON, United Kingdom Purpose or Objective The FiGaRO trial is a Phase 1 multicentre study that aims to determine the feasibility and safety of 18 F-FDG-PET/CT dose-painted IMRT in locally advanced oropharyngeal SCC. Dose escalation strategies are explored, with target volume definition and toxicity being the main challenges. It is well recognised that swallowing dysfunction is a