Controversy over the Use of Proton Therapy for the Treatment of Tumors of Central Nervous System


Klin Onkol 2018; 31(1): 24-27. DOI: 10.14735/amko201824.

Background: Proton beam therapy (PBT) is one of the most discussed topics in contemporary oncology. PBT is characterized by certain physical properties that make it theoretically better as a treatment than standard photon therapy. On the other hand, there are some uncertainties regarding the localization of the dose peak (Bragg peak) in real clinical situations and the value of radiobiological effectiveness at the end of proton beam. Unfortunately, the high expectations of PBT have not been fulfilled in published clinical studies. Aim: In the present article, the results of PBT are compared with those of standard photon therapy for the treatment of low-and high-grade gliomas, pituitary adenomas, vestibular schwannomas, chordomas and chondrosarcomas, and pediatric central nervous system tumors. PBT was not better in tumor control or in reducing toxicity than photon therapy. The higher risk of post-radiation brain tissue necrosis after PBT is alarming. PBT is mostly considered for pediatric tumors, because the radiobiological models predict lower damage to neurocognitive functions and a reduction in secondary malignancies. However, this hypothesis has its opponents and sufficient clinical data to justify the models are still lacking. The cost of PBT is several times higher than that of photon therapy. Results: PBT is a revolutionary technology in modern radiotherapy, but so far, clinical data have not proved it to be superior to that of standard photon therapy. PBT should be considered on an individual basis in cases where modern photon therapy cannot meet the dose limits of healthy tissues.

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