In the film The Fifth Element, Leeloo (though we do not yet know her name) lies wounded in an incubator. Peace-loving aliens have sent her, the Fifth Element, to Earth in order to save it. Leeloo first undergoes all kinds of scans, after which robot hands attend to her wounds. It's science fiction, admittedly - but not altogether. Jan-Jakob Sonke (48), physicist and head researcher in the radiotherapy department of The Netherlands Cancer Institute, works with image-guided radiation. This means that scans can be made during radiotherapy treatment, which allow doctors to modify the treatment plan, both making treatment much more precise and reducing the irradiation of healthy tissue.
Sonke: "Radiotherapy is often spread over daily sessions which often continue for four to six weeks, but the tumour and the surrounding organs look a little different every day. The bladder might be full or empty, for instance, and this will displace the tumour. A patient might have lost weight, through the combination of chemotherapy and radiotherapy. And the tumour itself might have shrunk as the result of treatment." Even breathing can influence the position of a tumour, as has been shown by 4D scans. "Yes, the fourth dimension describes time alongside place, by analogy to Einstein. Ultimately, a radiation beam ought to continuously follow these displacements."
Innovations in image-guided radiotherapy or adaptive radiotherapy (in which the radiation plan can be adapted in real time during the treatment itself, thanks to scanning information) have followed each other in quick succession over the last twenty years. The next big change will be the transition from CT-guided to MRI-guided radiotherapy. Sonke and his group are also researching into how this method could be improved still further.
"In the medical world I'm a real techie," says Sonke, smiling, perhaps with a good-humoured nod to his own appearance; he has more than a passing resemblance to Albert Einstein.
Sonke's employer has called him a thematrekker - a 'theme puller' - for the Netherlands Cancer Institute (Nederlands Kanker Instituut, NKI). "There are five fields, five themes, in which we want to excel: immunotherapy, quality of life, fundamental research, tailor-made treatments, and my own theme, image-guided therapy. A thematrekker looks for possible breakthroughs, opportunities for collaboration and strengthening. I'm the ambassador for this theme, and I advise our board of directors. My role is less of a hierarchical one than a connecting one."
"I've got the best job in the Netherlands," he adds. "I can indulge my fascination for science and technology, and I get to discover new things. There can be fewer more socially relevant workplaces than here, where I can make a contribution to cancer treatment."
Sonke's roots did not, however, lie in medicine - except for the fact that his father was a family doctor. "As a kid I liked making little machines. That was what I thought being a scientist meant. I studied physics at Delft, and for a while I wondered whether I was more of a 'tinkerer' than a fundamental scientist. My doctorate at Delft was ultimately in acoustics: what sound is like on stage, how the audience experiences it, and what you can do with technology to influence that sound. I was always involved in music - I play drums - so for my doctoral research I could combine both things, technology and music."
In 2000, Sonke noticed a vacancy at the NKI: the radiotherapy department was looking for a physicist. "Acoustics weren't going to be my thing after all. I was looking for something that had more social impact. I come from a socially engaged family background; my father was a GP and my mother was a womens' rights activist."
A revolution in radiotherapy had just been unleashed. "For the first time ever, patient anatomy could be imaged during a radiation therapy session using a CT scanner that was integrated into the radiation device. It felt like I was the right person in the right place at the right time."
The physicist and Nobel laureate Marie Curie (1867-1934) died of her own discovery: she worked frequently with radioactive radiation, and developed leukaemia. "There's something curious about the fact that we can use something both to cure cancer and to cause it. And it's always an odd contrast to see a patient being exposed to a radiotherapy machine while the treatment team retreats behind a wall. But two years after X-rays were discovered, they were already being used to treat cancer. Radiotherapy destroys a tumour by disrupting its DNA, and cancer cells also recover less well from radiation damage than do healthy cells."
A radiation therapy machine is an ingenious device in and of itself; Sonke's office contains a scale model of one. The patient lies on a flat couch. Above him hangs what looks rather like an enormous hair-dryer. This 'head' is the part that delivers the radiation beam. On either side of the patient are CT scanner modules. The 'gantry' can rotate 360 degrees around the patient, to deliver radiation from any angle.
Today's developments in imaging technology have made radiotherapy even more precise and effective. Sonke: "We can locate the tumour better, and damage less healthy tissue."
The next step is that the CT scanners in radiation equipment are replaced by MRI scanners. This has already started on a small scale, including at the NKI. "MRI is better at distinguishing different tissue types," the physicist explains. "That makes it easier to adapt the treatment plan to a daily-changing anatomical picture. Some of these machines are already available, but they're more complicated. The magnetic fields generated by the MRI and by the radiation beam can interfere with one another." One of the most exciting developments in image-guided therapy is the combination of medical scans with artificial intelligence, a technology which has long since moved beyond the realm of science fiction. "We're now letting machines solve problems independently. Computers can learn if you give them enough data. In oncology, too, we're working on algorithms like the ones that Facebook uses to recognize what's in a photo: you, or a dog, a cat or a cow..."
In this case, recognizing a tumour. "Or where the tumour is located, or how it can best be irradiated. AI also makes it possible to use our scans to say which patients have a good prognosis and which do not. You need very powerful computers for this work; the funny thing is that these computers weren't designed for scientists, but for gamers. Some of this equipment can already assess prognoses or carry out treatments better than people can. What we're aiming for is that the computer does as much as possible automatically, so as to be able to deliver the optimum treatment in an efficient and extremely accurate way."
Like the scene in The Fifth Element, in fact. "Radiotherapists won't lose their jobs - they'll simply be able to irradiate with much more precision. They'll retain control, and responsibility. Improved prognoses also make it easier for doctors to weigh up treatment options together with the patient, with information on the likelihood of recovery and of side effects, and to see their patients through an intensive course of treatment."
The Netherlands Cancer Institute (Nederlands Kanker Instituut, NKI) is the research institute of the Antoni van Leeuwenhoek hospital. Its aim is to better understand cancer in order to identify better cancer treatments.
The NKI in Amsterdam is one of Europe's top ten Comprehensive Cancer Centres: centres that bring cancer care and cancer research under one roof. About 700 scientists work at the NKI.
The physicist Jan-Jakob Sonke leads a group of researchers in the radiotherapy department. "Radiotherapy uses X-rays. That's pure physics," says the scientist. Sonke lives in Durgerdam, is married, and has two children.
Jan-Jakob Sonke has been an endowed professor of adaptive radiotherapy at the University of Amsterdam for a year. The radiotherapy departments of the Academic Medical Centre (AUMC) and the Netherlands Cancer Institute worked in close cooperation to achieve this appointment. Thanks to this chair, Sonke will be able to further develop his particular expertise: perfecting radiation treatments. Radiotherapy is one of the three most important forms of cancer treatment, and is employed in about half of all cancer patients. However, radiotherapy is also associated with toxicity. "The optimum treatment is a balance between the likelihood of recovery and an acceptable likelihood of side effects," according to the University of Amsterdam (UvA).
This is an article from Noordhollands Dagblad, Robbert Minkhorst.