ESTRO 2021 Abstract Book

S804

ESTRO 2021

and neck area, in regions previously irradiated, is surgery, but it is not always feasible. And results obtained exclusive chemotherapy are poor. We carry out an analysis of the current situation of patients receiving reirradiation (tumors recurrent or second tumor) in head and neck area. To evaluate the efficacy (survival and locoregional control) and safety of re-irradiation in head and neck cancer, in our institution. Materials and Methods Patients who were treated with curative intent have been selected. We study 85 patients, receiving the treatment between September 2003 and January 2018. A descriptive analysis, analytical study and statistical representation of univariate and multivariate survivals have been carried out. Results The median age has been 60 years. The interval between treatments had a mean / median of 66.42 / 35.50 months (m). In 34% of cases, the reason for re-irradiation was for second tumors. Second irradiation, 48.2% was performed with IMRT. The mean and median dose administered was 64Gy and 66Gy, respectively, receiving a dose ≥ 60Gy and 87.1% of patients. The treatment schemes were distributed as follows: 22.4% exclusive radiotherapy, 28.2% surgery and radiotherapy, 29.4% radiochemotherapy and 20% surgery followed by radiochemotherapy. Overall survival (OS) has presented a median of 14 months with a 95% interval confidence (IC) of 6.36-21.64. The OS at 12 m was 50.8% (IC 40.02-61.58), at 24 m of 37.9% (27.32-48.48), at 36 m of 29.8% (16.8-36.8); 4 years 25,5%. Disease-free survival (DFS) has presented a median of 9 m (IC 7.52- 10.48). The DFS at 12 m was 38.1% (IC 27.71-48.49), at 24 m of 28.1% (IC: 18.3-37.9) and after 36 m: 20.4% (IC 11.58-29.22); and free survival of loco-regional recurrence has presented a median of 28 m (IC 0-64.77). The SFLRR at 12 m was 60.4% (IC 49.23-71.57), 24 m of 52.2% (IC 39.85-64.55). 36 m of 46.8% (33.66-59.93). Metastasis-free survival at 12 m was 97.1% (IC 92.98-101.22), at 24 m: 94.7% (IC 88.62-100.77) and at 36 m of 87.1% (IC 75.53-98.66 9). We did not find toxicities greater than G3. Significant statistically significant factors (p <0.05) for OS were histology of the second disease, radiotherapy dose, surgery prior to radiotherapy treatment, the interval between the 2 diseases and the two radiotherapy treatments. Conclusion Re-irradiation with curative purposes is shown as a safe and effective treatment with acceptable toxicities in appropriately selected patients. It is established as an adequate alternative treatment for these patients. The most important factors to consider are interval between treatments, the disease-free interval, and optimal radiation doses. PO-0970 Impact nutritional intervention in patients with head and neck cancer receiving radiotherapy. L. Gutiérrez Bayard 1 , S. Sayago Gil 2 , C. Muñoz Higueras 1 1 Hospital Universitario Puerta del Mar, Oncology Radiotherapy, Cadiz, Spain; 2 Hospital Universitario Puerta del Mar, Oncology Radiotherapy, Cádiz, Spain Purpose or Objective To evaluate the benefit of motivational interviewing in addition to nutritional counselling in head and neck cancer (HNC) patients undergoing radiotherapy (RT), to improve patients' nutritional behaviors. during treatment and the first twelve months after completion. Materials and Methods Eighty-nine intervention patients received motivational interviewing and cognitive behavioral therapy compared to 67 historical controls who received treatment as usual. The intervention is based on behaviour change counselling methods, including motivational interviewing to improve motivation to eat despite a range of barriers (pain, mucositis, nausea, salivary toxicity, taste changes and appetite loss), and to provide patients with practical behaviour change strategies. Assessments will be conducted at 5 time points (first, third, five and final week of radiotherapy, 4 and 12 weeks 1, 3, 6 and 12 months after radiotherapy). The primary outcome was nutritional status at the end of RT as measured by the Patient Generated Subjective Global Assessment (PG-SGA). Secondary endpoints: quality of life (EORTC QLQ-C30) and anticancer treatment tolerance. Results Intervention patients resulted in smaller loss of body weight than control group (mean difference, 1.8 kg [95%CI, 0.65–2.5]; P = 0.005), and a clinically important reduction on the PG-SGA (34% of controls vs. 17% intervention; P = 0.04) in favor of the intervention condition. Secondary endpoints: reduced the need for changes in planned anti-cancer treatments (i.e., RT and/or systemic treatment dose reduction, interruptions or complete suspension) HR=0.38 [95%CI, 0.2–0.89], P = 0.03), and global QoL (P < 0.002) After treatment: Similarly, in Intervention control resulted in smaller loss of body weight than control group (mean difference, 2.4 kg [95%CI, 0.80–3.4]; P = 0.004), reduction on the PG-SGA in favor of the intervention (28% of controls vs. 13.6% intervention; P = 0.04) and global QoL (P < 0.002) Conclusion HNC patients undergoing RT (+/- systemic treatment), receiving motivational and nutritional Intervention resulted in better weight maintenance, and was associated with better anti-cancer treatment tolerance and improved quality of life. These measures are equally important during the first year after treatment.

PO-0971 Locally advanced oropharyngeal cancer: a dynamic nomogram F. De Felice 1,2 , L. Humbert-Vidan 3,4 , M. Lei 2 , A. King 4 , T. Guerrero Urbano 2

1 Sapienza University of Rome, Radiotherapy, Rome, Italy; 2 Guy's and St Thomas' NHS Foundation Trust, Clinical Oncology, London, United Kingdom; 3 Guy's and St Thomas' NHS Foundation Trust, Medical Physics, London, United Kingdom; 4 King's College London, Biomedical Engineering, London, United Kingdom

Purpose or Objective