Particle therapy in Europe

Abstract

Particle therapy using protons or heavier ions is currently the most advanced form of radiotherapy and offers new opportunities for improving cancer care and research. Ions deposit the dose with a sharp maximum - the Bragg peak - and normal tissue receives a much lower dose than what is delivered by X-ray therapy. Particle therapy has also biological advantages due to the high linear energy transfer of the charged particles around the Bragg peak. The introduction of particle therapy has been slow in Europe, but within the last decade, more than 20 clinical facilities have opened and facilitated access to this frontline therapy. In this review article, the basic concepts of particle therapy are reviewed along with a presentation of the current clinical indications, the European clinical research, and the established networks.

Keywords: cancer; ion beam therapy; particle therapy; proton therapy; radiation; radiotherapy.

Fig. 1

Physical and biological advantages of particle therapy (protons and carbon ions) as compared to megavoltage X‐rays (photons). The depth–dose curves of charged particles are defined by a plateau phase and the Bragg peak, situated in a specific depth depending on the energy of the beam.

Fig. 2

Graph showing the number of clinical proton facilities in Europe 2009–2020. Source: www.ptcog.ch.

Fig. 3

Comparison of treatment plans with X‐rays (left) and protons (right) for different tumor sites. Figure reproduced from Durante et al. (2019), reproduced with permission of Elsevier.