## Physics & Astronomy ETDs

Fall 11-10-2017

#### Abstract

The Bragg peak geometry of the depth dose distributions for hadrons allows for precise and effective dose delivery to tumors while sparing neighboring healthy tissue. Further, compared against other forms of radiotherapeutic treatments, such as electron beam therapy (EBT) or photons (x and $$\gamma$$-rays), hadrons create denser ionization events along the particle track, which induces irreparable damage to DNA, and thus are more effective at inactivating cancerous cells. The measurement of radiation's ability to inactivate cellular reproduction is the relative biological effectiveness (RBE). A quality related to the RBE that is a measurable physical property is the linear energy transfer (LET), a measurement of the deposited energy over the particle track. The purpose of this work was to develop a method of measuring LET of radiotherapeutic beams using an air-filled ionization chamber (IC) and liquid-filled ionization chamber (LIC). Through analysis of the IC and LIC signals, we determined a correlation between the recombination index (IC/LIC) and dose-averaged LET.

Physics

Doctoral

#### Department Name

Physics & Astronomy

#### First Committee Member (Chair)

Michael Holzscheiter

Shuang Luan

David Dunlap

Paul Schwoebel

English

#### Keywords

LET, HIT, Bragg Peak, Ionization Chamber, Radiotherapy

Dissertation

COinS