ESTRO 2020 Abstract book

S478 ESTRO 2020

conducted by the Japanese Radiation Oncology Study Group (JROSG) (clinical trial numbers: UMIN000011911). Results The median cycle of cetuximab was seven (1-9) and the median dose of radiotherapy was 70 Gy (34-75.1). The completion rate of BRT, defined as receiving minimum 6 cycles of cetuximab and 60 Gy of radiotherapy, was 77.2%, which was lower than that of reported series. Completion rate was especially low (57%) in patients over 75 years of age. The estimated 1-year loco-regional and progression- free survival was 56.1 and 51.5%, respectively. The major adverse event of Grade 3 or more developed pharyngeal mucositis (48.5%), radiation dermatitis (45.6%), and oral mucositis (40.4%), respectively. Respiratory complications such as aspiration pneumonia (4.7%) and pneumonitis (4.1%) were higher than previously reported, and 3 of the 12 cases that developed pneumonitis died. These pneumonitis most frequently developed on the eighth cycle of cetuximab administration, which seemed different onset compared to that of either radiation or drug induced pneumonitis. Conclusion Considering that there were many elderly patients in Japanese clinical practice, the efficacy of BRT is considered to be within the expected range. Careful management and adequate supportive care were considered necessary due to insufficient treatment completion and more acute adverse events than expected. PO-0797 Postoperative radiation to open head and neck wounds P. Hirapara 1 , A.K. Patidar 2 , K. Viroliya 3 , K. Jani 4 , S. Batham 4 , M. Jain 4 , M. Gandhi 4 1 HCG Hospital, Radiation Oncology, BHAVNAGAR, India ; 2 Sterling Hospital, Radiation Oncology, Rajkot, India ; 3 SMIMER, General Medicine, Surat, India ; 4 HCG cancer center, Radiation Oncology, Ahmedabad, India Purpose or Objective Oral cavity Squamous cell carcinoma (OCSCC) is leading cancer among male in Gujarat State of India and Majority of them are diagnosed at an advanced stage. Postoperative Radiotherapy-PORT/ChemoRadiotherapy-POCRT is used in loco regionally advanced OCSCC. Delayed wound healing is not an uncommon among loco regionally advanced OCSCC, and subsequent delay in PORT/POCRT beyond 6 weeks adversely affects loco regional control. Literature on Postoperative Radiotherapy to open wound is sparse. Material and Methods We did retrospective analysis of patients seen in our Institute from June 2018 to May 2019. We consulted 198 patients for postoperative radiation therapy and among them Seventeen(8.58%) patients had unhealed wound with or without fistula. Twelve of 17 patients (70.5%) gave written informed consent to have adjuvant RT/CRT with unhealed wound. We analysed treatment details, wound & disease status during & post RT. Results Mean delay of starting PORT/CRT was 3 weeks (Range 0-12 weeks). 2/12 had stage II, 2/12 had stage III, 4/12 had stage IVA & 4 had stage IVB. 7/12 had wound size less than 2 cm without fistula, 4/12 had wound size between 2-4 cm (1 with fistula and 3 without fistula), and 1/12 had wound size more than 4 cm without fistula. None of them had diabetes mellitus. 7/12 required PORT and 5/12 required POCRT (median-4 cycles, range-0-6 cycles). Mean Delivered RT dose was 55.8 Gy (Range 36-64Gy). Wounds closed spontaneously in 5/12 (having wound size less than 2 cm without fistula, Mean-1.8 weeks, Range 1-4 weeks) during PORT and six required surgical closure while 1 developed distant recurrence (while on POCRT at 4 th week, concluded POCRT at 36Gy/18fractions). One patient in this study died with cancer, three had local and/or regional failure & eight are alive without disease at median follow up of 6.5 months (Range 3-13 months).

Conclusion PORT to completely healed wound is always preferred though clinical dilemma arises for patients with incompletely healed wound. Although number in our study is less with short follow up, Our initial conclusion is that radiation therapy to small open wound without fistula with appropriate precaution can be considered if healing is delayed more than 6 weeks. Open wound can be surgically managed after completion of PORT if disease is controlled loco regionally but loco regional recurrence is rarely salvaged successfully. PO-0798 Early mortality after radical radiotherapy in head and neck cancer K.H. Jensen 1 , I.R. Vogelius 1 , M. Andersen 2 , J. Overgaard 3 , J.G. Eriksen 3 , M. Farhadi 4 , E. Andersen 5 , J. Johansen 6 , J. Friborg 1 1 Rigshospitalet- Copenhagen University Hospital, Department of Oncology, Copenhagen, Denmark ; 2 Aalborg University Hospital, Department of Oncology, Aalborg, Denmark ; 3 Aarhus University Hospital, Department of Oncology, Aarhus, Denmark ; 4 Zealand University Hospital, Department of Oncology, Næstved, Denmark ; 5 Herlev Hospital- Copenhagen University Hospital, Department of Oncology, Herlev, Denmark ; 6 Odense University Hospital, Department of Oncology, Odense, Denmark Purpose or Objective Radical radiotherapy (RT) or chemoradiation (C-RT) of squamous cell carcinoma of the head and neck (HNSCC) is associated with substantial toxicity. There is no consensus on comparative quality metrics for early mortality, but 90- day mortality has been suggested. The aim of this study was to investigate predictors and trends of 90- and 180- day mortality in a population-based cohort of head and neck cancer patients treated with RT/C-RT. Material and Methods A retrospective cohort study was conducted. Information on all HNSCC patients treated with RT/C-RT in Denmark between 2000-2017 was obtained from the national Danish Head and Neck Cancer Group (DAHANCA) clinical database. Deaths in patients with residual or recurrent cancer after RT/C-RT were classified as cancer-related. Predefined predictor variables were investigated using multivariable logistic regression. Results Overall, 11419 patients were identified and the 90- and 180-day mortality risks were 3.1% and 7.1%, respectively. During 2000-2017, there was a significant decrease in 180- day mortality, driven by a reduction in cancer-related events. We were unable to identify a high-risk section of the 180-day period. In multivariable analysis, increasing age, stage, performance status, earlier treatment year, and hypopharyngeal cancer were significantly associated with an increased risk of early mortality (p < 0.05). Except for earlier treatment year, these predictors remained significantly associated with early mortality in recurrence- free patients (p < 0.05).