ESTRO 38 Abstract book

S651 ESTRO 38

Material and Methods Twenty patients of locally advanced head and neck squamous cell carcinoma on radical concurrent chemoradiation were included. Acute toxicities were assessed at baseline, weekly and at the end of treatment by the radiation oncologists and patients themselves independently. National Cancer Institute’s Common Terminology Criteria for Adverse Events (CTCAE version 5.0) for 12 domains was used by the radiation oncologists while PROM for the same were recorded using PRO-CTCAE. At each point of assessment, the toxicity grades were compared in terms of agreement or disagreement between patients and physicians. The incidence, pattern and degree of disagreement between patients and physicians were analysed statistically. The relation between severity of toxicity and degree of disagreement were studied and plotted with Bland Altman Analysis. Results

20 male patients with mean age of 59 years with locally advance carcinoma of oral cavity, oropharynx, hypopharynx and larynx were assessed. 6 (30%) and 12 (60%) patients presented with T4 disease and Node positive disease respectively. All patients were treated with cisplatin based chemoradiation. 3DCRT or IMRT were used. 30-35% patients developed grade 3 acute toxicity in terms of dysphagia, mucositis or dermatitis as per CTCAE. No grade 4 or above toxicity was noted. Some degree of disagreement existed at baseline for symptoms like pain (10%), dysphagia (20%), anxiety (25%) and depression (20%). The agreement between physician assessments and PROM demonstrated a decreasing trend from 80-100% at baseline to 20-35% at week 6 of treatment for all domains. Maximum disagreement was observed with pain (80%) and Anorexia (20%) at 6 th week. The degree of disagreement (by one or two points) was found to be increasing with severity of toxicity grades (mean toxicity grade). The patient reported toxicity grades always remained higher across all domains towards the end of treatment. 3 patients required hospitalisation for toxicity management and treatment was interrupted for 4 patients. Conclusion The study found that a significant amount of disagreement exists between physician and patients and the gap increases with the severity of toxicity. The result evokes the thought that there is a possibility of under-assessment by the physician or over-assessment of acute toxicities by the patients which may ultimately affect the final clinical outcome. These two scales can be used as complementary tools to assess acute toxicities more accurately so that an early intervention can be done. This is an ongoing prospective study in our department.

Conclusion This analysis confirms that the current constraints used at CNAO are safe, but suggest that the D1% and D20% constraints could be increased to about 49 and 40 Gy(RBE LEM ), respectively. However, due to uncertainties in the recalculation method applied, and differences in the physical beam model of original NIRS and CNAO treatment planning system, only a partial and step-wise escalation of dose constraints should be done within protocols providing careful observation and revalidation. EP-1176 Comparison of patient and physician reported acute toxicities during head and neck cancer radiotherapy J. Bhattacharya 1 , A. Jawade 1 , P. Vijayaraghavan 1 , T. Shahid 1 , M. Mukherjee 1 , R. Talukder 1 , A. Samanta 1 , C. Saikia 1 , A. De 1 , D. Barman 1 , T. Ghosh 1 , S. Sadhukhan 1 1 Apollo Gleneagles Hospital- Kolkata, Radiation Oncology- Cancer Block- 1st Floor, Kolkata, India Purpose or Objective The purpose of our study was to prospectively assess and compare acute toxicities reported by radiation oncologists and patient reported outcome measures (PROM) during concurrent chemoradiation for locally advanced squamous cell carcinoma of head and neck. The aim was to find discordance between subjective and objective assessments and its characteristics.