ESTRO 2021 Abstract Book

S822

ESTRO 2021

objective of this study is to investigate predictive factors of severe mucositis in patients with locally advanced HNC treated with curative-intent radiotherapy, including the role of HPV status. Materials and Methods A prospective cohort study was designed. From April 2019 to December 2020, 45 HNC patients were enrolled. The primary endpoint was the development of Grade-3 (G-3) mucositis evaluated using the CTCAE V5.0 and RTOG scales. All patients received radical radiotherapy ± concomitant chemotherapy. Clinical and analytical factors were analyzed. This study has obtained the approval of the center's ethics committee and all patients were given informed consent. Results Mean age was 60 years and 68,9% were male. ECOG was ≤1 in 97,8% patients and the most frequent tumor sites were oropharynx (35,6%) followed by larynx (26,7%) and oral cavity (20%). Prescribed dose was 65,1Gy in 91,1% patients. With a mean follow-up of 13,6 months, we observed that 62,2% patients developed G-3 mucositis during antineoplastic treatment beginning at a median cumulative dose of 36,8Gy±11,2Gy. Multivariate regression analysis showed that oropharynx and oral cavity tumor sites (p=0,05) and HPV- (p=0,064) were correlated with the development of severe mucositis. In a subgroup analysis of oropharynx and oral cavity patients we found that 83,3% of HPV- developed severe mucositis compared to 41,7% in HPV+ group (p=0,08; RR: 2 [IC 95%: 0,97- 4,09]). Receiving a mean dose >40Gy or >8Gy per week to 21cc oral cavity was also associated with higher rates of mucositis (70% vs 31,8%; p = 0.03 and 75% vs 25%; p = 0.006, respectively). Conclusion To identify predictive factors that could determine the development of this severe toxicity would help us to establish prognostic groups and prevention strategies. Our first results suggest that HPV status might be associated to the acute mucositis grade. This study is currently under progress and further research is needed to confirm these findings. PO-0990 Treatment package time and Hb in head and neck SCC treated with surgery and post-operative RT C. Blake 1 , B. Hunter 1 , Z. Awad 2 , D. Gujral 2 1 Imperial College Healthcare NHS Trust, Head and Neck Unit, London, United Kingdom; 2 Imperial College London, Department of Cancer and Surgery, London, United Kingdom Purpose or Objective A previous retrospective study indicated a total treatment package time (PT) of <100 days was associated with superior tumour control and survival for patients treated with surgery (Sx) and postoperative radiotherapy (PORT) for head and neck squamous cell carcinoma (HNSCC). Other published data demonstrated high Haemoglobin (Hb) levels (>120 g/L) during RT confers significantly better survival outcomes, although transfusion did not improve outcomes. We examined PT and Hb on disease outcomes in patients with HNSCC treated with Sx and PORT. Materials and Methods A retrospective review was performed of consecutive patients with HNSCC, treated with primary Sx and PORT (≥50 Gy/20# over 4 weeks). All primary tumour subsites were permitted, including oropharyngeal SCC treated initially with primary neck dissection. PT was defined as the number of days from surgical date to completion of PORT, and classified as <100 days or >100 days. Hb was defined as the minimum recorded level during radiotherapy and classified as >120 or <120 g/L. Treatment response was assessed at around 12-16 weeks post-treatment using CT or PET-CT scan. Survival was assessed as time to recurrence, death or last follow up from completion of treatment. Results Between 05/2012 and 07/2018, 107 cases were identified. 87 (81.3%) completed PORT within 100 days. 41 (38.3%) maintained Hb >120 during radiotherapy. The median follow-up was 38 months for <100 days and 38.5 months for >100 days. PT analysis of <100 vs >100 days revealed no significant differences in disease-free survival (DFS) (median 36 vs 31.5 months, respectively; P=0.67), or overall survival (OS) (median 38 vs 38.5 months, respectively; P=0.11). DFS for Hb >120g/L vs <120g/L was significantly improved (median 40 vs 27 months, respectively; P=0.03). Subgroup analysis of PT <100 days indicated DFS for Hb >120g/L vs <120g/L was superior (median 40.5 vs 25 months, respectively; P=0.04), with no significant difference between high or low Hb for PT >100 days (median 40 vs 29 months, respectively; P=0.46). Conclusion Hb level during radiotherapy is a statistically significant prognostic biomarker for DFS, consistent with prior data. PT <100 days was not associated with improved survival outcomes, suggesting maintenance of Hb levels >120g/L during PORT is more important than time to completion of PORT. PO-0991 Impact of low muscle quality in patients with head and neck cancer undergoing chemoradiation L. BARDOSCIA 1 , P. Ciammella 1 , G. Besutti 2 , E. Bonelli 2 , A. Botti 3 , M. Pellegrini 4 , F. Vigo 1 , A. Rosca 1 , G. Timon 1 , S. Cozzi 1 , M.P. Ruggieri 1 , C. Iotti 1 1 Azienda USL-IRCCS di Reggio Emilia, Radiation Therapy Unit, Department of Oncology and Advanced Technology, Reggio Emilia, Italy; 2 Azienda USL-IRCCS di Reggio Emilia, Radiology Unit, Department of Imaging and Laboratory Medicine, Reggio Emilia, Italy; 3 Azienda USL-IRCCS di Reggio Emilia, Medical Physics Unit, Department of Oncology and Advanced Technology, Reggio Emilia, Italy; 4 Department of Biomedical, Metabolic and Neural Sciences University of Modena and Reggio Emilia, Clinical Nutrition Unit Azienda Unità Sanitaria Locale – IRCCS di Reggio Emilia, Modena/Reggio Emilia, Italy Purpose or Objective To explore the impact of low skeletal muscle mass and quality on disease free survival (DFS), overall survival (OS), treatment tolerance in patients undergoing radical chemoradiation (CRT) for head-and-neck squamous