New tool slashes radiotherapy time for head cancer tumours

A CANCER tool that can drastically reduce the time some patients need radiotherapy for head and neck tumours has been developed by British experts.

The new method uses a machine combining MRI imaging and X-rays to give a quick and accurate look at the cancer’s location and automatically adjusts the aim of the treatment with 99.9 per cent accuracy.

This process can cut the time spent administering radiotherapy down from two hours to as little as 30 minutes, according to the team of researchers from the Institute of Cancer Research and The Royal Marsden NHS Foundation Trust in London.

More than 12,000 people in the UK are diagnosed with head or neck cancer every year, and treatment involves radiation being used to shrink a tumour while the patient lies motionless inside a mask that protects healthy tissues.

“When I started training, we basically laid someone down on the bed, put a plastic mask on them and took some X-rays from the front and the side,” said Prof Kevin Harrington, head of radiotherapy and imaging at the Institute of Cancer Research.

“We would then blast away at them every day for six or seven weeks, treating the same area irrespective of the fact that during the treatment the patient would lose up to ten per cent of their body weight.

“Their body would shrink, the shape of the area we were radiating would shrink and, as they subsided and lost weight, the position of their head would slightly change and we wouldn’t adjust one iota to that, we just carried on the way we were.”

In an ideal world, Prof Harrington said, scans would be done every day to create a bespoke programme overseen by a doctor, but this is extremely time consuming and labour intensive, needing up to two hours per session.

By using the Mr-linac machine the team of scientists, funded by Cancer Research UK, found a middle ground between the customised method and the older inflexible approach.

“The technique cuts out a very laborious, time-consuming step without any detriment to our ability to target the cancer, as we found it to be 99.9 per cent as good as a fully bespoke programme,” said Prof Harrington.

A study, published in the journal Clinical and Translational Radiation Oncology, used the method on two patients and found that of more than 50 doses of radiation delivered, just one exceeded the acceptable threshold.

In contrast, the previous approach scored just 92.4 per cent.

“The failure rate of the old approach was as high as 7 per cent which means that there was a significant risk of either missing the tumour target, and therefore reducing the chance of curing the disease, or overdosing the normal organs and increasing the risk of toxicity,” Prof Harrington said.

He hopes the technique will be used in the future to treat other cancers, including those of the pelvis, prostate, cervix and bladder.