Particle therapy, the new therapeutic procedure, now makes it possible to target some cancers specifically – a milestone in cancer care. This technique accelerates protons and carbon ions to almost two thirds of the speed of light and puts them precisely in the tumor. During this process, the ion beam penetrates the tissue up to 30 cm and deviates from the region of interest by no more than half a millimeter.
The advantages of this procedure: the range can be precisely calculated and the ion beam controlled with millimeter precision. Thus, cancerous cells are struck directly, while the surrounding healthy tissue remains untouched. In conventional radiation, the dose decreases as penetration depth increases. With proton and ion beams, the dose increases gradually and drops suddenly after reaching a sharp maximum – the so-called Bragg Peak.

Particle therapy opens up entirely new treatment opportunities: It is especially well-suited for tumors that are located near high-risk organs (brain, spine, nerve pathways) or were once difficult to treat or completely untreatable because of their location. Over 40,000 patients have already been treated with proton therapy. Carbon ion therapy is currently being used at three institutions worldwide, among them the Society for Heavy Ion Research, or GSI, in Darmstadt.
Since 1997, the GSI has been conducting clinical trials in collaboration with the Heidelberg University Hospital to document the efficiency of particle therapy using carbon ions, particularly for chordomas and subcranial chondrosarcomas. Over 2,000 patients have already been treated with carbon ions in studies being done in Chiba, Japan, with equally excellent results. The Chiba studies also indicate that the number of treatment sessions may be reduced, from 30 to just 10 in some cases.
Another advantage of particle therapy is that it has virtually no side effects. A hospital stay is required in exceptional cases only.