Wednesday 2 November 2016

MR linac is a pioneering new form of radiotherapy that can ‘see and treat’ cancer with pinpoint accuracy - Shaun Atherton

Shaun Atherton, radiotherapy physics team manager for technical services

Shaun Atherton
It seems a long time since The Christie first became part of the Elekta MR-linac consortium. For those who don’t know what that is, MR-linac is a pioneering new form of radiotherapy machine that can ‘see and treat’ cancer with pinpoint accuracy. 

MR-linac combines magnetic resonance imaging (MRI) scanning and tumour-busting radiotherapy treatment in one hi-tech package – and it will be one of only seven in the world! 

We are very lucky to be working with one of the world’s leading providers of radiotherapy equipment, Elekta, as part of a worldwide consortium with seven other world class cancer centres and the technology giant Phillips to bring MR-linac to The Christie.

As with any big project of this nature there have been numerous challenges to overcome and many ups and downs along the way, but it is here at last!

The Linac ring
The bunker that the MR-linac will be situated in has been one of the biggest challenges. We discovered that there’s a lot of history buried in that bunker which has housed lots of different types of radiotherapy machine (Linac) in the past. When I first joined The Christie in 1993, it was a Philips SL75-14, and before that it was a HILETRON. For the last 12 years it has been a Elekta Synergy Linac.

This history made it difficult to find accurate records for the bunker and made for a fascinating journey for both designers and building contractors. Thankfully, having paid a fixed price for the building work, the costs of this project have remained in budget.

Initially, the Elekta Synergy Linac that has been used for the past 12 years was removed by the physics team at The Christie. This machine itself was revolutionary at the time, having a cone beam CT imaging system, which has now become the gold standard for radiotherapy imaging. Our MR-linac will carry on the fine Christie tradition of being at the cutting edge of radiotherapy technology.

Once the Synergy Linac had been removed, the building contractors, DD Porters moved in to start the refurbishment of the bunker and control area. The build has taken many turns, including encountering steel where it shouldn’t have been, removing iron reinforcing bars and replacing them with MR friendly steel reinforcement bars and also underpinning a primary radiation barrier.

The whole bunker had to be excavated. As the Linac is wrapped around an MR unit it has to be partially installed below floor level, to allow the radiographers to work at arms level and for the Linac part of the machine to rotate 360 degrees around the patient. 

The building contractors also had to remove any iron reinforcements to ensure there was no effect on the magnetic field for the 1.5 tesla MR scanner, causing image distortions or induced magnetism which could affect any equipment in this bunker in the future. This was a very labour intensive process. As the bunker is landlocked, access to it was through the main radiotherapy department, creating its own unique issues, especially with cleaning.

Lifting crane
The safety of our staff, patients, and the public is our top priority on a project like this. That’s why a team of experts from Christie Medical Physics and Engineering have looked at radiation protection very carefully to ensure that MR-linac is totally safe for everyone. 

Once all the excavations had occurred to strip the bunker back to its shell, and to ease
delivery, DD Porters had to start putting it back together. All of the concrete had to be manually lifted into the bunker and there were many long evenings to get this finished.

MR-linac ring entering the hole in the roof
The delivery of the main components for the MR-linac was a very well thought out process. It involved closing Wilmslow Road on Sunday 9th October from 4am until early evening to allow the crane to do its work. The crane needed over 100 tonnes of counterbalance to safely lift the largest parts of the MR-linac and the length of the crane arm was over 40m. 

The next exciting phase of the work will be fitting the RF cage in November, an enclosure used to block electrical fields which might otherwise interfere with the very sensitive equipment inside. Once this is done, we can finalise the installation and get the equipment working. 

Elekta along with Christie medical physics and engineering and the MR-linac project team will be working closely together to ensure this state of the art equipment delivers world class treatment to Christie patients in the future. Whilst this is happening, our clinical staff will be working on how best to use the new technology to treat patients and which patients will get the greatest benefit from MR-linac. As nobody has yet treated a patient with an MR-linac anywhere in the world, much of this work will be done through research activities.
Patient facilities including waiting area, changing rooms and treatment room


Finally, work is continuing to provide a world class suite for patients to make their experience as friendly and safe as possible. 

Our MR colleagues from diagnostic radiology and the MR scientists were crucial in designing this area.

I feel truly privileged to be involved in such an exciting and innovative project, having to solve complex problems day in and day out. I know more than anything that everyone who is involved in this project is working together as one team to bring the very latest technology to The Christie and to ensure that our patients get the very best treatments they can for their cancer.

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