Gavin Pikes: Monte Carlo Modelling in Linac Shielding

Monte Carlo Simulations in the Modelling & Optimisation of Linac Bunker Shielding
By: Gavin Pikes

Supervisors
Dr. David Pfefferlé (Department of Mathematics, UWA)
Dr. Pejman Rowshan Farzad (Department of Physics, UWA)

Significance
In radiotherapy, linacs typically employ a beam energy of 6 to 18 MeV [4]. Such a beam is designed to treat patients by precisely targeting and killing cancer cells with an extreme dose of radiation (X-rays). According to the linear non-threshold theory currently recommended by the International Commission on Radiological Protection, the risk of cancer will increase proportionally with any dose of radiation to healthy tissue [6]. As a result, those not undergoing treatment must take care to minimise exposure to any of the radiation produced. For perspective, the prescribed dose limit given by the Australian Radiation Protection and Nuclear Safety Agency is 20 mSv per year for radiation workers. As such, adequate shielding is crucial to protect the staff and public in a linac’s surroundings. By bolstering shielding in any potentially weak areas, as well as examining the effect of material and geometric changes, and any novel additions, recommendations can be made in regard to improving the shielding capabilities of linac bunkers.
An optimisation of bunker design not only allows for improved shielding capabilities, but the potential to reduce unnecessary shielding, leading to a decrease in construction cost. As linac bunkers can cost upwards of $750,000 AUD, any reduction in unneeded components can save thousands of dollars in materials and labour, as well as increasing the availability of another vital resource: space. For 2 reference, it has been found that using shielding assumptions that are too conservative can increase bunker cost by up to 43%.

=========================
For more information visit our
Website: https://www.uwamedicalphysics.org
Weblog: http://www.uwamedicalphysics.com
Facebook:   / uwa.medical..  .
Instagram:   / uwa_medical.  .
Twitter: @MedicalUwa
YouTube Channel:    / @medicalphysicsuwa  
=========================