Ionization chambers modeling for dosimetry phantoms development

Abstract

Radiation treatment is an important modality in treating diseases especially cancer. Although it is important in medicine, improper use can lead to unnecessary dose exposure, cancer or in extreme cases, death. Therefore, treatment plans are tested and verified with phantoms and detectors before they are administered to patients. Ionization chambers are detectors used to measure the quantity of ionization radiation that is deposited in the patient. Three dimensional (3D) printing on the other hand is a manufacturing technique that has revolutionized medical physics through the production of patient specific phantoms with accuracy compared to other methods. This method is cheap, fast, allows the production of complex geometries with precision and the use of different printing materials, and less time consuming. Incorporating cavities for detectors in 3D printed phantoms allows precise positioning of detectors for accurate dose measurements and verification. The study aimed at investigating the feasibility of using 3D printing to replicate the structure of original ionization chambers. Models of three different ionization chambers were designed with computer aided design (CAD) software, and printed. The printed prototypes were then examined using computed tomography scanner to access their accuracy. The result confirms that 3D printing can produce ionization chamber prototypes. When developing 3D printed phantoms with cavities for the insertion of original ionization chambers, these printed prototypes can provide accurate reference dimensions for the cavities