In the dead of night back in
This article takes a behind-the-scenes look at the team of professionals who overcame a variety of obstacles when installing this equipment and managed to start treatment. To reach that point, a team of dedicated professionals had to overcome a number of obstacles.
Most of us have been touched by cancer, directly or indirectly. In
Dr.
There are three main cancer treatments: surgery, chemotherapy, and radiotherapy. Each has its own strengths and weaknesses, but generally speaking radiotherapy, which uses ionizing radiation to irradiate and kill cancer cells, imposes less physical burden and has fewer systemic effects. In recent years, the spotlight has centered on the higher energy levels and greater accuracy of heavy ions.
A characteristic of heavy ions is that when they reach a certain depth in the body, depending on their initial energy, the energy they impart to their surroundings increases dramatically through ionization*. X-rays and gamma ray beams are different. They scatter as they go deeper into the body; they are most effective close to the surface and weaken as they penetrate further. It is difficult to use them to irradiate cancerous cells deep in the body, but normal cells on or near the surface are damaged.
When radiation passes through a material, the energy of the radiation repels the electrons (negative charge) of the atoms in the material and separates them into positively charged atoms and free electrons.
By adjusting the energy delivered and delivering peak ionization-the Bragg peak-to the site of the tumor being treated, heavy ions destroy cancerous tumors while minimizing damage to surrounding normal cells. This precision also reduces physical burdens and side effects, adding to the reason why heavy-ions systems are expected to be widely adopted for next generation cancer treatment.
A compact rotating gantry achieves the world's smallest heavy-ion radiotherapy system
The system at East Japan Heavy Ion Center has brought a paradigm shift and new hope for cancer treatment to Tohoku. But completing installation and starting treatment relied on the dedication and commitment of many professionals in a number of fields. We talked to some of them, from the East Japan Heavy Ion Center, B dot Medical, a start-up established in
Broadly, a heavy-ion radiotherapy system comprises two elements: a synchrotron, a kind of particle accelerator; and a treatment area. The synchrotron accelerates carbon ions, a particle with a greater mass than helium, known as a heavy ion, to about 70% of the speed of light. This vastly increases their energy. From the accelerator, the carbon ions travel through a high-energy transport system to irradiation ports in the treatment area, and so to the patient as a heavy-ion beam.
The treatment area has two rooms, one with a fixed horizontal beam port, the other housing the rotating gantry. Both accommodate patients on a treatment couch, a robotic arm with seven joints. Optimal positioning are determined from images of the irradiation field.
The rotating gantry is a major technological advance in its own right. The use of superconducting magnets allows it to move freely through 360 degrees, and irradiate heavy ion beam from any angle, which eliminates the need to put patients in uncomfortable positions, reducing stress while significantly expanding the scope of treatment. On top of all this rotating gantry for heavy-ion therapy is the world's smallest, making it relatively easy to install.
Other advantages that make heavy-ion beam therapy a compelling treatment option include automated patient positioning, respiratory-gated irradiation for organs moving with breath, and scanning irradiation technology.
Perseverance in fine tuning for precision and safety
A heavy-ion beam radiotherapy system in an amalgam of advanced technologies, and its installation and optimization are crucial-much more so than with standard radiotherapy systems. Before operation could begin at Yamagata, there were some major hurdles to get over, not least the adjustment of the accelerator and irradiation with the beam.
Dr.
'With any radiation source, there is the risk of leaks into the surrounding area. It has to be shielded, and meet the standards of the
This high precision work was undertaken by B dot Medical. It's a start-up that grew out of
'Our first difficulty was projecting an accelerated beam from the accelerator. That really didn't go well, and took almost a month longer than expected. I knew that we wouldn't get inspection by the
While all this was going on, Souda was still optimistic about progress, at least at the beginning. 'The system at the Center was the second Toshiba installed,' he explains. 'The first was a system called i-ROCK, installed at the
As Souda speaks, Dr.
'The systems in
Expectations from doctors and patients soared, with treatment reservations more than tripling expectations!
Unfortunately, there isn't a magic wand that can deliver the ideal with a single wave. Everyone involved realized they were installing completely new equipment; they had to forget past successes and advance by making adjustments one at a time, one after another. Thankfully, one adjustment that went particularly smoothly was to the line that carries the heavy ion beam from the accelerator to the treatment area. The team were very careful when measuring the magnetic fields of the superconducting magnets.
'A really slight deviation in the magnetic field, even one close to zero can shift the beam position around 1 mm,' explains Saraya. 'If a number of them had overlapped, the beam would not have made it to the treatment area, and something like that could have delayed the start of treatment by another two months or more. We had a hard time with i-ROCK because there was room for improvement in the magnetic field measurement, but this time we were able to make use of that experience.'
As progress inched forward, the date for starting treatment was finalized:
'Those last six months were the most important for equipment adjustment,' says Kanai. It was also a period of growing interest in the new unit. 'Every two or three days, doctors treating cancers would contact us to ask, 'Is it really on time?' Naturally enough, they wanted their patients to receive high quality care as soon as possible.' That was a goal that motivated everyone involved in the East Japan Heavy Ion Center, including Kanai: 'I must do all I can to make it happen on time,' he told himself.
The team's efforts paid off, and on the due date. On
Part 2 will delve into the challenge of developing software that makes heavy ion cancer therapy more effective, and technology that not only improves patient care but reduces costs.
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