Scan that lets doctors see live video of the cancer they're zapping2020-03-14
Scan that lets doctors see live video of the cancer they’re zapping
- In England alone, 134,000 radiotherapy ‘episodes’ are delivered each year
- The MRIdian machine has been hailed as the smartest radiotherapy treatment’
- Professor Pat Price explained how the new technology improves accuracy
Half of all patients diagnosed with cancer will undergo radiotherapy — an important and effective tool in the arsenal against the disease.
However, even with precise planning, radiotherapy treatment can go awry. The normal workings of the body during treatment — breathing, the bladder filling, digestion, tensing up — can make a tumour move up to half an inch, causing the radiation beams to damage healthy tissue instead of killing cancer cells.
There are techniques used to avoid this, such as breath-holding for breast cancer to prevent radiation from damaging the heart, and filling of the bladder with water before undergoing radiotherapy to the pelvis.
These low-tech techniques rely on creating a barrier between the radiation and healthy tissue, but now a pioneering new radiotherapy machine can overcome this problem.
Professor Pat Price who is the chair of the charity Action Radiotherapy, explained how the MRIdian machine could improve radiotherapy treatment (file image)
Hailed as the ‘world’s smartest radiotherapy treatment’, the MRIdian machine uses magnetic resonance imaging (MRI) to provide live, detailed images of the tumour and surrounding tissue, like a continuous film rather than a snap shot — and if the tumour moves even a fraction, the machine automatically cuts out to avoid healthy tissue being hit.
The increased accuracy of the new method will allow higher doses of radiation to be used, making it likely cancers can be eradicated sooner.
It is particularly useful for treating prostate, liver, pancreatic and lung cancers that haven’t spread, because these are situated close to major organs which, if damaged, can have devastating side-effects. For example, radiotherapy for prostate cancer can cause incontinence and sexual dysfunction if the surrounding tissues are damaged.
‘This technology ensures the radiotherapy is going in the right place,’ says Professor Pat Price, chair of the charity Action Radiotherapy.
‘It’s a real breakthrough and is certainly the future of radiotherapy.’
Radiotherapy kills cancer cells by damaging their DNA.
In England alone, 134,000 radiotherapy ‘episodes’ — as each session is known — are delivered each year, in conjunction with treatments such as chemotherapy and surgery.
Improving the accuracy of radiotherapy has long been the quest of cancer specialists. Recent improvements in its precision means that rather than the traditional 20 or 30 radiotherapy sessions for early-stage prostate or lung cancer, for example, many patients receive only five, higher-dose treatments.
Precise radiotherapy, known as stereotactic radiotherapy (radiotherapy from many different angles around the body given by machines known as Linacs or linear accelerators), improves survival in early stage lung cancer by 30 per cent using fewer, high-dose treatments, according to research from the CHISEL trial, published in The Lancet in 2018.
Robin Chudley, 65, (pictured) from Northampton, who was diagnosed with prostate cancer last August had treatment with Dr Camilleri at his Oxford clinic in December
Similar outcomes were seen for prostate cancer in another UK study, reported last year in the journal, Lancet Oncology.
The latest technology — a type of magnetic resonance linear accelerator (MR Linac), a machine that combines MRI scanning and radiotherapy to precisely locate tumours — takes it a step further.
Not only does it use extremely precise radiotherapy beams from up to 200 angles to target the exact position and shape of the tumour, but it continually scans the body throughout the process.
This prevents the need for surgically implanted ‘markers’ to guide the radiotherapy beams, but means treatment takes an hour rather than a matter of minutes, and patients have to lie inside an MRI scanner during treatment — making it unsuitable for those who are claustrophobic or have an implanted pacemaker or defibrillator.
‘The prostate can move as much as 10mm to 12mm in any direction due to changes in the anatomy from day to day, and this treatment allows us to adapt the radiation field to these daily changes, ensuring treatment is as accurate and effective as possible,’ explains Dr Philip Camilleri, clinical director of urological cancers at the private GenesisCare clinic in Oxford — the first place in the UK to offer this particular machine for treating a range of cancers.
A ten-year collaboration with the University of Oxford, announced last year, means NHS patients on clinical trials will benefit from the technology, too.
‘The machine scans and tracks the tumour during treatment and the radiotherapy beam automatically stops if the target moves out of the zone even by a little bit,’ says Dr Camilleri, who also works as a clinical oncologist in the NHS at Oxford University Hospitals.
‘It means I am confident that high doses of radiation are being delivered on target virtually 100 per cent of the time and organs are being avoided.
Tests revealed that Robin’s PSA (prostate specific antigen) results have fallen (file image)
‘There are fewer treatments, so it is less disruptive to patients’ lives. It’s a big step forward.’
It is already being used for other cancers, such as lung and liver. ‘These patients are able to view the tumour on a screen during the treatment which can minimise movement,’ Dr Camilleri adds.
Private treatment using the new technology, made by the U.S. company ViewRay, costs around £30,000. The NHS has two MR Linacs, and a different type made by Elekta — at the Royal Marsden Hospital in London and the Christie Hospital, Manchester — and other private clinics have the technology, too.
Almost 50 patients with prostate, rectal, bladder, cervical, ovarian and head and neck cancers have been treated at the Royal Marsden using this technology, and 15 prostate cancer patients have been treated at The Christie.
So far 25 patients have undergone treatment for various cancers at the Oxford clinic. Among them is Robin Chudley, 65, a company director from Northampton, who was diagnosed with prostate cancer last August.
He’d had annual tests for PSA (prostate specific antigen), a marker for prostate cancer, on the NHS for a number of years because of a family history — and last May the test showed his levels were 5.9 (under two is normal). A biopsy and scan confirmed it was cancer.
‘I was given the option of various treatments: prostate removal, undergoing 20-25 days of conventional radiotherapy, hormone treatment or five higher doses of radiotherapy on the new machine. I chose the latter because it was less disruptive, yet had the same results,’ he says.
The treatment with Dr Camilleri at his Oxford clinic was carried out over five days in December.
Rose Gray who is a policy manager at Cancer Research UK, said there is more to be done despite the huge progress in radiotherapy (file image)
‘There was no discomfort and I listened to music while I was in the cylinder,’ Robin says.
He was playing tennis and golf three weeks after the treatment finished, and tests since have shown that his PSA levels have fallen dramatically.
Yet despite these scientific advances, most NHS radiotherapy is still very basic because many machines are out of date.
In 2016, the Government announced a £130 million upgrade programme. However, only 69 out of 272 radiotherapy machines in England have been replaced, according to a written Parliamentary answer last year, and further funding has not been announced.
A recent inquiry by the All-Party Parliamentary Group on Radiotherapy found that only 25 of the 52 NHS radiotherapy centres offer advanced radiotherapy for early-stage lung cancer, even though it is recommended by NICE and is linked to a 30 per cent improvement in survival.
Rose Gray, policy manager at Cancer Research UK which is campaigning for improvements in radiotherapy, says: ‘Radiotherapy is a cutting-edge, life-saving treatment which has seen huge progress, but there is more to be done.
‘If hospitals are to give cancer patients the best possible radiotherapy treatment, the Government must invest more in staff to fix current shortages and plan for rising demand in the future.’
Bad, good, best: How to get the most out of food choices.
This week: Cauliflower
BAD: Battered and fried.
Frying doesn’t affect levels of glucosinolates — compounds in cruciferous veg thought to have anti-cancer properties — but an eighth of a cauliflower head portion contains around 270 calories if prepared this way, and up to 20g of fat. Plus, the creamy dip you’ll want to eat it with contains lots more.
GOOD: Raw crudities.
Raw cauliflower has the most vitamin C — a 100g serving has 56mg of it, which is more than half your daily amount of the compound needed for healthy skin, gums and blood vessels. Tahini dip is a good pairing as the vitamin E it contains works with vitamin C in helping to keep the immune system healthy.
BEST: Roasted with parmesan.
Make this by roasting a head of olive oil-coated cauliflower for 30 minutes, then tossing in 8 tsp of parmesan. Per serving (it makes six) it has only about 71 calories and 2g of saturated fat — compared with 250 calories and 9g saturated fat in cauliflower cheese. A serving has an eighth of your daily calcium needs.
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