ESTRO 2021 Abstract Book

S808

ESTRO 2021

(10%). There were 2 cases each of oral cavity and unknown primary SCC. After a median follow up of 46 months 21% (11/52) of the anatomical group and 26% (5/19) of the geometric group developed recurrent disease. All nodal recurrences occurred within areas of gross disease at diagnosis and were within the GTV for treatment planning. The median volume of tissue receiving high dose radiotherapy was 566cc (range 144 – 1113cc) in the anatomical group compared to 150cc (range 29 – 452) in the geometric group. AKI or need for admission occurred in 38% (14/37) of patients receiving 3-weekly cisplatin compared to 11% (2/11) of patients receiving weekly cisplatin. This translates to a 3.45 fold increased risk of AKI or admission in patient’s receiving the 3-weekly regime. Conclusion Both groups had good outcomes with no recurrences at 3 years in 71% of the anatomical and 68% of the geometric group. This compares favourably to national data for outcome where 5-year survival rates in England as of 2006 ranged from 26-65% across all head and neck subsites. The good outcomes with small numbers of recurrences means it is not possible to detect any statistically significant difference between the two comparison groups. All recurrences occurred within the GTV suggesting an anatomical delineation technique may lead to larger volumes receiving higher doses with limited apparent benefits for recurrence. 3-weekly cisplatin chemotherapy combined with high dose radiotherapy over a large volume may lead to higher rates of AKI and hospital admission. The findings from this study suggest reducing the proportion of tissue receiving high dose radiation may help to reduce toxicity without compromising locoregional control . PO-0975 ICT Plus Simultaneous Modulated Accelerated Radiation Therapy in Non-operative SCCH/L B. Cai 1 , L. Ma 1 , L. Meng 1 , J. Mo 2 , S. Xu 1 , B. Qu 1 , F. Liu 1 1 The First Medical Center of Chinese PLA General Hospital, Radiation Oncology, Beijing, China; 2 the 921st Hospital of Chinese PLA, Radiotherapy, Changsha, China Purpose or Objective To evaluate the toxicities and long-term outcome of induction chemotherapy (ICT) plus simultaneous modulated accelerated radiotherapy (SMART) in non-operative hypopharyngeal and supraglottic laryngeal squamous cell carcinoma (SCCH/L). Materials and Methods Patients diagnosed SCCH/L, aged from 18 to 75, either staged retrospectively from III to IV B, in accordance with the AJCC 2010 criteria, or refused operation were eligible. The patients were treated with 2 cycles of docetaxel-cisplatin based ICT, and 2-3 cycles cisplatin-based concurrent chemotherapy combined SMART. The prescription dose of pGTV was 69 Gy, in 30 fractions, 2.30 Gy per fraction. This was a prospective study and began enrolling patients since February 2013, acute reaction and long-term outcome were analyzed. Results Between February 2013 and June 2015, 55 newly diagnosed SCCH/L patients were enrolled. Acute xerostomia > grade 2 was not noted. The incidences of grade 3 acute skin reaction, oral mucositis and pharyngo- esophagitis were low, 12.7% (7/55), 3.6%(2/55) and 12.7% (7/55),respectively. The median follow-up time was 48.0 months. The main late adverse reaction was hoarseness or sore throat, the incidence was 32.7% (18/55).The 5-year functional larynx-preservation survival rate was 51.5%.The 3-and 5-year LC and OS was 58.2% and 51.5%, 63.6% and 54.1%,respectively. Conclusion The ICT plus SMART regimen of 69Gy/30f in the treatment of SCCH/L demonstrated minor severe toxicities, satisfied long-term outcome and laryngeal function preservation rate. PO-0976 Adjuvant (chemo)radiotherapy in HNSCC patients: Outcome prediction with comorbidity risk scores S.N. Marschner 1,2 , C. Maihöfer 1 , R. Späth 1 , N. Kienlechner 1 , L. Schüttrumpf 1 , P. Baumeister 3 , J. Hess 4 , H. Zitzelsberger 4 , A. Friedl 1 , U. Ganswindt 5 , C. Belka 1 , F. Walter 1 1 University Hospital, LMU Munich, Department of Radiation Oncology, Munich, Germany; 2 German Cancer Consortium , (DKTK), Munich, Germany; 3 Ludwig-Maximilians-University, Department of Otorhinolaryngology- Head and Neck Surgery, Munich, Germany; 4 Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Research Unit Radiation Cytogenetics, Neuherberg, Germany; 5 Medical University of Innsbruck, Department of Therapeutic Radiology and Oncology, Innsbruck, Austria Purpose or Objective Patients with head and neck cancer frequently present with multiple comorbidities. Undergoing adjuvant (chemo)radiotherapy, these may have an impact on patient outcome. For patient assessment the performance status according to Eastern Cooperative Oncology Group (ECOG PS) is routinely used in oncology. This score is easy to assess but succumb to inaccuracy due to subjectivity. More elaborate performance scores such as the American Society of Anaesthesiologists' (ASA) and the Adult Comorbidity Evaluation-27 (ACE27) can be used. The purpose of this study was to evaluate whether more objective indices provide additional information to stratify patient outcome and how these score perform compared to established predictive factors. Materials and Methods We retrospectively reviewed 302 consecutively treated patients with newly diagnosed head and neck squamous cell carcinoma treated with adjuvant (chemo)radiotherapy between 06/2008 and 06/2015 at the Department of Radiation Oncology at the University Hospital, LMU Munich. Data was analyzed for outcome and treatment failures in correlation with known risk factors e.g. HPV, and tumor stage, and three different validated comorbidity risk scores: ECOG-PS, the ASA-Score, and the ACE27. Survival analysis was performed using the Kaplan-Meier method, groups were compared using log-rank test.