Linear Accelerator Bunker Refurbishment

 

The installation of the latest Varian Truebeam Accelerator at Dunedin Public Hospital provides us with the opportunity to treat more patients and cancer types" says Matthew Paris, Professional Director of Medical Physics / Principal Physicist. "Its advanced technology is engineered to deliver more precise radiation doses to smaller areas, allowing treatment of the most challenging cases".

The installation involved de-commissioning and removing one of the hospital's three existing linear accelerators. This provided the opportunity to simultaneously replace the cooling system and chiller plant and upgrade the radiation shielding associated with the three accelerators, which each sit on a thick concrete plinth housed within its own concrete and steel-plated radiation proof bunker. This formed the first two stages of the project.

Stage three involved the installation and commissioning of the new linear accelerator. To accommodate its larger size its bunkers existing concrete plinth had to be cut out and re-oriented and the radiation shielding upgraded to 400mm thick concrete walls lined with 200m thick inter-locking steel plates.

Flexible programming, construction ingenuity, close communication with SDHB staff and night and weekend work shifts were key to resolving the many challenges associated with working in a confined, irradiated, environment. One of the hospitals key requirements was to ensure that the number of radiation treatment appointments on a day-to-day basis was maintained throughout the construction and commissioning period. This was achieved despite only two of its three linear accelerators being available during this time.