ESTRO 37 Abstract book

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ESTRO 37

post-treatment. An MDADI was posted to 54 alive and disease-free patients after a 30 month interval. 52/55 replies were received, median of 64 months (range 52-88) post-treatment. 27/52 (52%) had been managed with a prophylactic gastrostomy. A 10-point or greater change of the MDADI scores was defined as clinically significant. Results Patient reported swallow function significantly improved on the second MDADI (>5 years post-treatment) compared with the first MDADI (>2 years post-treatment) for composite (p=0.018) and global scores (p=0.035), emotional (p=0.040) and functional domains (p=0.045), with a non-significant improvement for the physical domain (p=0.122). Using the composite score, a clinically significant improvement in swallow function over time was noted in 17/52 (33%) patients; conversely 6/52 (12%) of patients experienced a clinically significant deterioration with time. Abnormality of pre-treatment diet and a prophylactic gastrostomy weakly correlated with an inferior MDADI composite score on the later questionnaire (p=0.029 and p=0.033 respectively). Conclusion Long term dysphagia is prevalent >5 years post- treatment. Long term dysphagia is not static; on MDADI composite summary scores 33% of patients experienced an improvement whilst 12% deteriorated with time. Further investigation is needed to determine underlying mechanisms behind these divergent outcomes. EP-1156 Set-up errors in head and neck cancer patients undergoing IGRT. Relationship to BMI and weight loss. A. Allajbej 1 , F. Patani 1 , M. Trignani 1 , A. Di Pilla 1 , P. Bagalà 2 , A. Vinciguerra 1 , G. Caravaggio 1 , M.D. Falco 2 , D. Genovesi 1 1 "SS.Annunziata" Hospital- "G. D'Annunzio" University, Radiotherapy, Chieti, Italy 2 "SS.Annunziata" Hospital- "G. D'Annunzio" University, Medical Physics, Chieti, Italy Purpose or Objective Assessment of translational and rotational set-up errors in head and neck cancer patients treated with IMRT and VMAT using daily pretreatment CBCT guidance and correlation between set-up errors and patient-specific factors (weight, height, BMI and weight loss). Material and Methods A total of 274 CBCTs referred to 30 patients were investigated. A customized immobilization system was employed during both planning CT and treatment phase. CBCTs were obtained according to an internal protocol consisting of 4 consecutive CBCTs during the 1 st week of treatment and weekly afterward. Mean translation of first 4 CBCTs was calculated; this value was considered as systematic set-up error; displacements >3 mm were corrected, according to literature data and action limit defined in our protocol. Action limit for rotation acceptance was ≤3°. Mean translations for CBCTs weekly performed during the remaining treatment course were calculated, too. For each patient, height, weight and BMI (pre, mid, end of treatment) were recorded. Percentage of weight loss (mid- and at end treatment) was calculated. Statistical analysis was performed to evaluate correlation between translational displacements and body changes. Results Oral-oropharyngeal and larynx were the most common sites treated. Mean translational and rotational set-up errors during the first 4 CBCTs were 0.15 cm (LR), 0.1 cm (AP), 0 cm (CC) and 0.7°(LR-axis), 1°(AP-axis), and 0.6°(CC-axis). Mean translations and rotations of subsequent CBCTs were 0.02 cm (LR), 0.03 cm (AP), 0 cm (CC) and 0.6°(LR-axis), 1°(AP-axis), and 0.7°(CC-axis). Median pre-treatment height, weight and BMI were 170.2 cm (148-186), 77.97 kg (42-114) and 26.72 (18.58-34.58),

respectively. All patients presented weight loss. Median weight variation at the 15 th treatment session was 4.3% (1.28-11.1) and at the end of treatment was 7% (2.56- 17.46). Statistical analysis showed no statistically significant correlation between mean displacements of first four CBCTs and mean of following CBCTs and no statistically significant correlation was observed between set-up errors and both BMI or weight change during treatment sessions. Conclusion Translations and rotations recorded in this study were in agreement with literature data. Weight loss occurred in all treated patients but was not found any correlation between patient weight, BMI or weight loss. Therefore, we cannot support the hypothesis that set-up errors during radiotherapy are correlated to patient weight, BMI or weight loss. EP-1157 Efficacy and Toxicity of Proton with Photon Radiation for locally advanced Nasopharyngeal Carcinoma A. Beddok 1 , G. Noel 2 , L. Feuvret 1,3 , S. Bolle 1,4 , P. Herman 5 , R. Dendale 1 , V. Calugaru 1 1 Institut Curie, Centre de Protonthérapie, Orsay, France 2 Centre Paul Strauss, Département de radiothérapie, Strasbourg, France 3 Centre Hospitalo-Universitaire Pitité Salpétrière, Service de radiothérapie, Paris, France 4 Institut Gustave Roussy, Département de radiothérapie, Villejuif, France 5 Centre Hospitalo-Universitaire Lariboisière, Service d'oto-rhino-laryngologie, Paris, France Purpose or Objective The aim of this study was to assess the treatment outcome and toxicity in patients with stage III-IVa nasopharyngeal carcinoma (NPC) treated with an association of proton and photon and chemotherapy. Material and Methods Between November 1999 and September 2016, seventeen patients with a median age of 49 years (range, 20-72 years) were treated for a stage III-IVa NPC at the Orsay Protontherapy Center of Curie Institute. Eighty-percent of the patients had T4N0M0 disease at diagnosis. The median administered dose in the primary tumour volume was 70 Gy (RBE) (range 70 – 78 Gy (RBE)). Bilateral lymph node in the neck (I – V levels) received from 40 to 54 Gy with photon beam. The primary tumor volume included microscopically extensions received a complementary dose (boost) with proton. The chemotherapy regimen consisted of 3 cycles of concurrent Cisplatin (100 mg/m2) on days 1, 22, and 43; 13/17 patients received neoadjuvant chemotherapy. The end-points of the study were locoregional control, survival, and treatment- related toxicity. Toxicity was graded with the NCI Common Terminology Criteria for Adverse Events version v4.0. Results After a median follow-up of 98 months (range, 5 – 208 months), there were two local relapses and two patients had developed distant metastasis. The actuarial local progression free survival and the actuarial overall survival were respectively 94% and 88% at 2 years, 86% and 74% at 5 years, 86% and 66% at 10 years. The grade ≥ 3 acute adverse events were alopecia (6/17 patients), dermatitis (3/17), mucositis (6/17) and weight loss (3/17). The mean weight loss was 7%, two patients required gastrostomy tube placement during treatment and one patient required parenteral nutrition. The grade ≥ 3 late adverse events were sphenoid bone radionecrosis (1/17) and hearing loss (4/17). Five patients required tympanostomy tube during treatment and three patients required definitive hearing aid. Dosimetric analysis showed that a dose in the internal ear > 74Gy was associated to more frequent hearing loss.