Ion beam radiobiology and cancer: time to update ourselves.
High-energy protons and carbon ions exhibit an inverse dose profile allowing for increased energy deposition with penetration depth. Additionally, heavier ions like carbon beams have the advantage of a markedly increased biological effectiveness characterized by enhanced ionization density in the individual tracks of the heavy particles, where DNA damage becomes clustered and therefore more difficult to repair, but is restricted to the end of their range. These superior biophysical and biological profiles of particle beams over conventional radiotherapy permit more precise dose localization and make them highly attractive for treating anatomically complex and radioresistant malignant tumors but without increasing the severe side effects in the normal tissue. More than half a century since Wilson proposed their use in cancer therapy, the effects of particle beams have been extensively investigated and the biological complexity of particle beam irradiation begins to unfold itself. The goal of this review is to provide an as comprehensive and up-to-date summary as possible of the different radiobiological aspects of particle beams for effective application in cancer treatment.
Fokas
Emmanouil
E
Department of Radiotherapy and Radiation Oncology, University Hospital Giessen and Marburg, Medical Faculty of Philipps University, Baldingerstrasse, 35043 Marburg, Germany. fokas@med.uni-marburg.de
Kraft
Gerhard
G
An
Hanxiang
H
Engenhart-Cabillic
Rita
R
D000818:Animals; D024201:Bystander Effect; D002244:Carbon / Q000627:therapeutic use*; D002453:Cell Cycle; D004249:DNA Damage; D042822:Genomic Instability; D063193:Heavy Ion Radiotherapy; D006801:Humans; D018499:Linear Energy Transfer; D009369:Neoplasms / Q000532:radiotherapy*; D061766:Proton Therapy; D012062:Relative Biological Effectiveness
D002244:Carbon