a novel method of quantitative comparison of the benefit and the risk of hydrogen and select heavy ions radiotherapy on breast cancer tumor using SRIM ion transport code.

Charged particle therapy has been an important procedure in non-invasive treatment of tumors. It utilizes the ionization pattern of protons and heavy ions to administer lethal doses of radiation to tumor tissues by destroying their ability to replicate. The use of charged particle therapy to control tumors non-invasively offers numerous advantages such as high Relative Biological Effectiveness (RBE) value. However, in this process, some doses of radiation are given to the healthy cells on the radiation path. This poses some risk. How do we quantify this risk?

In this work, we present a new way of quantifying the relative radiation dose given to cancerous and healthy tissues on the radiation path. The ratio of the average dose rate in Bragg peak (calculated from the FWHM from a gaussian fit do dose rate data) to average dose rate in the plateau region is used to quantify the benefit and potential risk of using Hydrogen, Helium, Carbon, Oxygen, and Neon ions in the treatment of a breast cancer tumor, assumed to be located  at a depth of 62 mm. Stopping and Range of Ion in Matter (SRIM) was used to get the dose rate.

Furthermore, the relative benefits were compared among the four ions with Neon, followed closely by carbon, found to offer the best advantage.