Modified intensity modulated radiotherapy reduces dysphagia in patients with head and neck cancer

Research shows that precision radiotherapy can reduce long-term side effects for patients with head and neck cancer following treatment.

Published: 08 June 2022 Radiotherapy

Described as ‘practice changing’, two-year results from the Dysphagia-Aspiration Related Structures (DARS) trial, which is funded by Cancer Research UK and the National Institute for Health and Care Research, were presented this week at the American Society for Clinical Oncology (ASCO) Annual Meeting.

Around 12,400 people are diagnosed with head and neck cancer in the UK each year and about 70% are left with life changing side effects including swallowing problems, making it difficult to eat and drink, after radiotherapy.

Researchers found that patients experienced less adverse side effects if they were treated with dysphagia-optimised intensity modulated radiotherapy (DO-IMRT), compared with standard IMRT.

DO-IMRT, which has been pioneered by researchers from The Royal Marsden Hospital and The Institute of Cancer Research, London, is optimised to reduce the risk of swallowing difficulties, known as dysphagia. It does this by reducing radiation to the pharyngeal muscles, which support swallowing.

The randomised phase III study found double the number of patients treated with DO-IMRT (40%) reported being able to swallow as well as ever compared with those treated with standard IMRT (20%) two years following treatment. Patients who received DO-IMRT had also previously reported better swallowing function at 12 months compared those who received standard IMRT.

Of those treated with DO-IMRT, over four in five (81%) reported high normalcy of diet - meaning they were still able to eat at least some foods that require chewing - and over nine in 10 (92%) said they felt comfortable eating in public, compared with just under 73% and 85% of those treated with standard IMRT respectively. 

The study included 112 newly diagnosed patients with oropharyngeal and hypopharyngeal cancers (tumours of the throat) from centres across the UK and Ireland. Half received standard IMRT and half received DO-IMRT every day for six weeks.

There was no evidence of a difference in survival rates between the two approaches.

 The DARS trial was coordinated by the Clinical Trials and Statistics Unit at The Institute of Cancer Research, London and was supported by strong collaborations between participating centres and a multidisciplinary team of doctors, speech and language therapists (SLT), radiographers, research nurses and physicists.

Professor Chris Nutting, consultant clinical oncologist at The Royal Marsden NHS Foundation Trust and professor of radiation oncology at The Institute of Cancer Research, London, said:

 “This practice-changing study represents a major step forward for treating head and neck cancer patients. We’ve shown that this optimised IMRT treatment can spare patients’ swallowing muscles and, crucially, without lessening the success of their treatment.

 “This new technique, which can have a major impact on a patient's quality of life, is achievable for all centres currently offering IMRT. It simply requires some additional time from the radiation oncologist and physicist to make adjustments to help reduce the irradiation of the muscles that control swallowing. Next, we’re planning to teach others around the world how to reproduce this new treatment approach.”