ESTRO 2020 Abstract book

S480 ESTRO 2020

CTV and 54Gy/1.8 Gy/fr in low risk CTV, given in 30 fractions. 51 pts (73%) received concurrent CDDP-based chemotherapy (CRT). Pts were examined once a week during radiation therapy, after 1, 3, 6 and 9 months, then every 6 months up to 5 years. Acute and late toxicities were graded using CTCAE 4.0 and LENT SOMA respectively. Response was assessed according to the RECIST criteria. Survival data were up-dated from regional database system The median follow-up of patients still alive was 4.98 years (range 1.9-8). Results 67 pts completed the planned schedule (compliance 96%). The median overall treatment time was 46 days (range 40- 62). The following severe acute toxicities were observed: 17% G3 skin reactions, 9% G3 mucositis, 14% G3 dysphagia, 16% G3 hematological toxicity (all with concurrent chemotherapy). Four G3 in RT alone and 35 G3 in CRT group respectively. One patient died because of fatal bleeding during radiotherapy. The following late severe toxicities were observed: 1% G3 xerostomia, 3% G3 and 7% G4 dysphagia. One patient died 10 months after the end of RT of epidural abscess in low-dose field. No chondronecrosis of the larynx was observed. Response was assessed in 66 pts (94%). A complete response (CR) was observed in 60% of pts, a partial response (PR) in 21%, stable disease (SD) 1% and 10% experienced a progression disease (PD).15/41 pts with CR had a progressive disease: 7 locoregional recurrences (4/7 underwent salvage surgery/radiotherapy), 8 distant recurrences. For all pts, the median OS was 2.46 years and the 3-years OS resulted 47%. The median PFS was 2.2 years and the 3-years PFS resulted 41%. The 3-years OS were 69% in larynx, 67% nasopharynx, 58% hypopharynx, 36% oropharynx and 25% oral cavity. The 3-years survival were 100% and 41% for stage I-II and III-IV respectively. At the time of data analysis (October 2019), 33/70 pts were alive. No differences statistically significant were found in Multivariate analysis considering stage, primary, overall treatment time. Conclusion Hypofractionated SIB-IMRT for locally advanced HNSCC not selected pts with or without chemotherapy is feasible and produced good results in term of response rate, PFS, OS. Hypopharynx and larynx primary tumor showed superior overall survival over the current standard. PO-0802 Impact of LINE-1 methylation on survival in patients with locally advanced oropharyngeal carcinoma. G. Fanetti 1 , V. Lupato 2 , M.T. Casarotto 3 , S. Sulfaro 4 , V. Giacomarra 2 , C. Furlan 5 , V. Baggio 6 , S. Romeo 7 , P. Boscolo-Rizzo 8 , E. Vaccher 9 , G. Franchin 1 , J. Polesel 10 , E. Fratta 3 1 Centro di Riferimento Oncologico CRO di Aviano- IRCCS- National Cancer Institute, Division of Radiation Oncology, Aviano, Italy ; 2 General Hospital “S. Maria degli Angeli”, Unit of Otolaryngology, Aviano, Italy ; 3 Centro di Riferimento Oncologico CRO di Aviano- IRCCS- National Cancer Institute, Division of Immunopathology and Cancer Biomarkers, Aviano, Italy ; 4 General Hospital “S. Maria degli Angeli”, Division of Pathology, Aviano, Italy ; 5 Ospedale San Martino di Belluno, Division of Radiotherapy, Belluno, Italy ; 6 Treviso Regional Hospital, Division of Radiation Oncology, Aviano, Italy ; 7 San Donà di Piave Hospital, Division of Pathology, San Donà di Piave, Italy ; 8 Treviso Regional Hospital- University of Padua, Department of Neurosciences- ENT Clinic and Regional Center for Head and Neck Cancer, Treviso- Padova, Italy ; 9 Centro di Riferimento Oncologico CRO di Aviano- IRCCS- National Cancer Institute, Division of Medical Oncology and Immune-related Tumors, Aviano, Italy ; 10 Centro di Riferimento Oncologico CRO di Aviano- IRCCS- National Cancer Institute, Unit of Cancer Epidemiology, Aviano, Italy

PO-0800 Outcomes of patients with locally advanced oral cavity SCC treated radically at Guys' Cancer Centre K. Sambasivan 1 , A. Michaelidou 1 , G. Ross 1 , R. Oakley 1 , A. Lyons 1 , L. Cascarini 1 , A. Fry 1 , J. Jeannon 1 , M. Reis Ferreira 1 , M. Lei 1 , T. Guerrero Urbano 1 1 Guy's and St Thomas' NHS Foundation Trust, Clinical Oncology, London, United Kingdom Purpose or Objective Cancer of the oral cavity is a common disease, constituting one third of all head and neck cancers. The optimal management of locally advanced oral cavity cancer is surgery and post-operative radiotherapy (PORT) +/- chemotherapy, with primary radiotherapy being reserved for the minority of cases unsuitable for surgery. The purpose of this study was to report on disease outcomes for patients with oral cavity squamous cell carcinoma (OCSCC). Material and Methods A retrospective analysis was performed on all patients with OCSCC receiving radical post-operative intensity modulated radiotherapy (PO-IMRT) between March 2010 and March 2018. Data were collected from electronic records, imaging and pathology reports. Statistical analysis was done using Graph Pad Prism software and survival outcomes calculated using the Kaplan Meier method. Results 160 patients with locally advanced OCSCC received IMRT. 9 patients who received primary IMRT alone and 1 who died on treatment were excluded from the analysis. Of 150 patients, 5 did not complete treatment (4 through choice and 1 due to aspiration pneumonia). There were 37% female and 63% male patients. 82.7% of patients had stage 4a disease and 17.3% had stage 3 disease. 57 patients received concomitant chemotherapy. Median follow up for all patients was 24.9 months and 39.9 months in survivors. Overall survival was 77.2% at 1 year, 60.2% at 3 years and 55% at 5 years. Disease free survival was 73% at 1 year, 68.3% at 3 years and 68.3% at 5 years. Conclusion This retrospective analysis provides survival outcomes for a large cohort of patients with OCSCC treated over an 8 year period. Considering that >80% of patients had stage 4 disease, our data show excellent 5 year outcomes with >50% of patients being alive at 5 years and nearly 70% being disease free at this point. PO-0801 Hypofractionated radiotherapy for HNSCC: a retrospective analysis of single Institution F. Sanna 1 , F. Cabras 1 , A. Carai 1 , S. Marogna 1 , A.R. Musu 1 , E. Orefici 1 , G. Piredda 1 , P. Pittau 1 , C. Sini 1 , M. Urpis 1 , L. Pelagatti 2 , M.C. Santona 2 , M. Giobbe 2 , L. Bandinu 2 , S. Cau 2 , L. Canu 2 , F. Salis 2 , S. Dei 2 , F. Capelli 2 , S. Campoccia 1 1 Ospedale San Francesco Nuoro, Radioterapia Oncologica, Nuoro, Italy ; 2 Ospedale San Francesco Nuoro, Multi Disciplinar Team-Head&Neck, Nuoro, Italy Purpose or Objective This study evaluates retrospectively clinical outcomes of simultaneous integrated boost (SIB-IMRT) hypofractionated radiotherapy for head and neck squamous cell carcinoma (HNSCC). Material and Methods We analyzed 70 HNSCC ECOG PS 0-2 pts treated with hypofractionated SIB-IMRT between 2011 and 2017. The median age was 60 years (range 43-86), 83% males and 17% females,. The primary tumor were 40% oropharynx, 23% larynx, 17% hypopharynx, 7% oral cavity, 6% unknown primary, 4% nasopharynx, 3% others. Patients were staged with TC scan and PET/TC. Stage (AJCC-7 th edition) was 67% IV a-b, 19% III, 10% II, 4% I. All patients received SIB-IMRT consisted in 67.5 Gy/2.25 Gy /fr in high risk CTV, 60Gy/ 2.0 Gy/fr in medium risk