IT'S been three years since proton therapy was thrust into the UK's spotlight, following the case of Ashya King.
Little Ashya was just five when he came to the Proton Therapy Center (PTC) in Prague for treatment to his aggressive brain tumour.
At the time his case sparked a fierce debate - should parents be given the final say on how their child is treated?
Now, the technology is back in the spotlight.
But this time it's as Manchester's Christie Hospital becomes the site of the UK's first NHS-funded proton therapy machine.
As an oncologist I'm thrilled to see the UK finally embracing protons on home soil.
But there's still a very, very long way to go.
The capacity for the new proton therapy centres set to open in England - including one at University College London - will be for less than one per cent of all UK cancer patients.
Their focus primarily will be on paediatric cancers and cancers in the head and neck.
At the PTC, our patient numbers have more than doubled year on year since we opened in 2012.
Last year we treated 800 patients, including a large number from the UK and Ireland. The vast majority of these patients funded their care privately as they were rejected for funding on the NHS.
And as awareness grows we expect to see even more patients from the UK and Ireland, where proton therapy is not yet available.
Around 40 to 50% of all the patients we see are suffering from prostate cancer - the most common cancer in UK men.
Many of these men are terrified by the thought of the side effects of surgery and traditional radiotherapy, which include double incontinence and erectile dysfunction. So they start researching the alternatives - and it inevitably leads them to proton therapy.
Traditional radiotherapy uses high energy beams to target and kill cancerous cells but in the process surrounding tissue can also be damaged. This can lead to side effects.
With proton therapy, high-speed particles are targeted at the cancerous cells with pencil-point precision. Once they hit the cells they stop, sparing the healthy tissue surrounding the tumour.
In an area as delicate as the prostate, this is particularly important.
We conducted our own study on a small sample of 86 male prostate cancer patients who had proton therapy over the course of two years.
Side effects were found to be minimal, and the cancer is currently undetectable in all patients observed in the study.
Long term data will be provided in due course but at the moment, the information we have points to a remarkable success rating.
Despite this, doctors in the UK are still reluctant to acknowledge the benefits of proton therapy over existing radiotherapy techniques in many cases, especially when it comes to reducing side effects.
In the last three years, the NHS spent £43.4million sending 489 patients to countries including the USA, Switzerland and Germany for proton therapy treatment.
Almost three quarters of the patients were children - making up 342 of referrals. The technology has proven to be particularly effective in young patients whose organs are still developing and in combating tumours that are close to critical structures.
Certainly in the immediate future the NHS will continue to send suitable patients abroad for treatment as construction on the two new sites continues.
And while the new centres are undoubtedly a step in the right direction, we're still facing an uphill struggle to champion the benefits of proton beam therapy as far and as wide as we can.