PUBLIC LECTURE – 22 AUGUST 2017

2017 Alexander and Leicester McAulay Winter Lecture Series

Australian Institute of Physics – Tasmanian Branch

Measuring Radiation Doses in 3-D with Polymer Gel Dosimeters

Tuesday 22 August 2017, 8.00-9.00 pm
Physics lecture Theatre 1
University of Tasmania, Sandy Bay Campus, Hobart

 

Professor Clive Baldock
University of Tasmania

Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record clinical radiotherapy (radiation therapy) radiation dose distributions in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry will be reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry will be presented.