Feasibility Of Using Ebt2 Radiochromic Film And Mosfet For Radiotherapy Dose Measurement In Nasopharynx Cancer Treatment

• Main Author: Eng, Kae Yann
• Format: Thesis
• Language: English
• Published: 2017
• Subjects: QC1 Physics (General)
• Online Access: http://eprints.usm.my/47521/1/ENG%20KAE%20YANN.pdf%20cut.pdf; http://eprints.usm.my/47521/

Nasopharynx cancer (NPC)’s tumour volume located at the head and neck which nearby with bundles of organ at risk (OAR). Therefore, it is important to have radiotherapy dose verification prior to the treatment. This is to make sure adequate dose delivered to tumour volume whereas protect well to organ at risk. Dosimetry response of both Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and Radiochromic EBT2 film were characterised before the dose verification of radiotherapy treatment was conducted. The characterisation of Radiochromic EBT2 film was ruled out from the tests which contributed combined standard uncertainty 5.05%. Tests are film reproducibility (0.25%), film darkening effect (0.25%), field size dependence (4.98%), and angular dependence (2.01%). Seven experiments were undergone to contribute 3.48% combined standard uncertainty for MOSFET. The experiments are MOSFET reproducibility (1.36%), fading effect (2.00%), perturbation (2.58%), linearity (2.88%), field size dependence (2.90%), angular dependence (3.36%), SSD dependence (2.59%). After the characterisation of Radiochromic EBT2 film and MOSFET, treatment plan dose verification was conducted in vitro. It showed a trend that measured doses higher than calculated doses by Treatment Planning System (TPS). TPS doses verified both dosimeters doses within 10% variation. Thus, both Radiochromic EBT2 film and MOSFET were suitable to be used as radiotherapy