• A Review on Proton Mini Beam Radiation Therapy Efficiency and Applications
  • Mahboobeh soleimanpoor,1,* Marziyeh Tahmasbi,2 Mahmood Mohammadi Sadr,3 Mohammad Ghaderian,4 Mohammad Farhadi Rad,5 Hossein Azadinejad,6
    1. Department of Radiology Technology, School of Allied Medical Sciences, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
    2. Department of Radiology Technology, School of Allied Medical Sciences, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
    3. Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
    4. Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
    5. Department of Radiology and nuclear medicine, School of paramedical, Kermanshah University of Medical Sciences, Kermanshah, Iran
    6. Department of immunology, school of medicine, Kermanshah university of medical sciences , Kermanshah,Iran


  • Introduction: Radiation-induced toxicity is a major concern in radiotherapy which is dependent on the dose, dose rate and spatial fractionation of the dose. This study aimed to review the proton mini beam radiation therapy (pMBRT) technique and applications as an innovative method based on dose spatial modulation to increase skin sparing and reduce radiation toxicity.
  • Methods: The database of PubMed and Google Scholar explored with different combinations of terms: proton mini beam radiation therapy, spatial modulation, dose distribution, treatment response, survival rate. Totally 114 articles were obtained. The obtained results screened for title and abstract. Finally, 31 more relevant papers were reviewed full text and included in the study.
  • Results: Unlike the conventional proton therapy, the irradiation is carried out with a very narrow beam (diameter ≤1 mm), separated by gaps of 2 to 4 mm in pMBRT. This method is promising in terms of reduced side effects and superior tumor control for patients with high-grade glioma compared to common radiotherapy techniques. Also, has been widely used for radioresistant tumors close to a sensitive structure or pediatric cancers, in which dose escalation in the target volume without increasing the dose to adjacent normal tissues is essential. The superior normal tissue sparing and potential advantages in tumor control using pMBRT allows temporal fractionation of dose, which makes it possible to deposit higher and potentially curative doses in clinical cases where tissue tolerances are a limit for conventional methods.
  • Conclusion: pMBRT allows escalation of tumor doses and greater sparing of normal tissues which potentially improves the probability of local control for tumor and survival rate as well as reducing toxicity and improving quality of life.
  • Keywords: Proton Mini Beam Radiation Therapy, spatial modulation, dose distribution.