Even after decades of battling one of the world’s biggest killers, the treatment of cancer is still an inexact science.Successful methods such as chemotherapy work by killing the cancer cells, but they also destroy healthy tissue.

Health practitioners have been searching for a magic bullet that goes straight to the source of the cancer — and everything from monoclonal antibodies, which carry cancer drugs direct to cancer cells, to straight surgery to cut out tumors have been used with varying degrees of success.

“In this space we accelerate the protons and we give them a higher and higher velocity until they reach two thirds of the speed of light — that’s 200,000 km per second and this acceleration takes place in the shape of a spiral,” a researcher said.”That’s needed if you want to be able to penetrate one foot into the body of a patient.”

While proton therapy is a giant step forward, it’s not yet the magic bullet that clinicians are looking for. So far, it is not effective against all types of cancer.

“There are a number of cancers which are not localized,” he said. “If you look at leukemia, which is cancer of the blood cells, there is nowhere to shoot — it’s all through the body.”

While the proton therapy market is expected to more than double by 2018, with an estimated 300 proton therapy rooms, Jongen’s Brussels-based company IBA is working on a smaller and cheaper model they hope will make proton therapy more accessible.

“I have a number of letters from parents of young kids saying if it had not been for this treatment we would have lost our kid,” he said.

“That’s something I really cherish. When I feel a bit depressed, for whatever reason, I go back to those letters and they are very exciting.”