Building safe radiation treatment rooms

A mock-up of a high-density concrete wall was constructed as part of the requirements to construct the radiation suites at the Walker Family Cancer Centre. The concrete walls are up to five feet thick to contain the radiation.

At about 67,000 square feet, the Walker Family Cancer Centre will occupy the first and second levels of a four-storey ambulatory care building at the new healthcare complex.
Level one: Main entrance and public facilities, four radiation therapy rooms, conference/education centre and supportive care
Level two: Outpatient clinic, systemic oncology/chemotherapy, satellite pharmacy, clinical trials and medical staff facilities

When it opens in 2013, the Walker Family Cancer Centre will become the hub of a coordinated regional cancer treatment network for Niagara, meaning that 95% of Niagara cancer patients will be able to receive their chemotherapy and radiation treatment in Niagara.

The Outpatient Oncology Clinic – established by Hotel Dieu Hospital and now operated by Niagara Health System – has provided chemotherapy treatment, diagnostic procedures, education and follow-up care in Niagara for 25 years. However, cancer patients must travel to Hamilton or beyond for radiation treatment each year. This year, the number of patients currently leaving the region for radiation treatment is estimated at 1,200.

In planning for the new cancer centre, which will have the capacity for four radiation treatment rooms, the NHS is working in partnership with the Juravinski Cancer Centre and Cancer Care Ontario, the provincial agency responsible for overseeing cancer services.

Radiation therapy is often used to treat or cure cancer or it can be used to provide relief from symptoms in cancers that have spread to other parts of the body. Treatment is provided by linear accelerators (LINAC), powerful X-ray machines that produce ionizing radiation to direct radiation beams to the patient’s tumour from different angles in order to destroy tumour cells.

“Essentially, these are fancy X-ray machines such as the ones you might find in an X-ray department,” says Alan Rawlinson, Project Manager of Medical Physics for Cancer Care Ontario. “However, these are more powerful and capable of penetrating the body by using high-energy, or ionizing radiation beams in a finely-focused way. These beams are strong enough to damage or kill cancer cells and stop them from dividing and spreading.”

In a typical radiation session, the patient lies on the couch positioned under the LINAC, which is capable of rotating in circles to allow the beam to be directed to the patient’s tumour region.

“Because X-rays can do harm to healthy cells by destroying the cell’s ability to divide, we need to ensure the amount and direction of radiation is correct and minimized to the surrounding healthy tissue,” explains Alan.

To do this, the NHS must comply with stringent national and international standards set by Canadian Nuclear Safety Commission (CNSC) to ensure staff and public safety.

“We must be careful that staff and visitors are not exposed to radiation as a consequence of using these machines. This is done by paying attention to design of the facility and by putting ongoing safe radiation safety measures in place.”

For example, the walls of the treatment rooms housing the LINACs are constructed out of concrete with thickness of up to five feet to contain the radiation.

“Our design also employs a doorless entrance maze system that interlocks,  allowing staff to get in and out of the room without radiation escaping while the machine is on, without the need for heavy shielding. There are also safety systems built into the design of the room to prevent accidental radiation.”

The combined planning team has followed a rigorous process submitting the design of the shielded radiation facilities to the CNSC. This has resulted in the NHS receiving formal approval this past December to construct the cancer centre as designed.

“Even though this step has been achieved, we will still have to get final approval to test the machines, and then obtain a licence to run the machines which means we’re able to guarantee that we use this facility in complete safety,” assures Alan.

The concrete forming the ground floor of the cancer centre was complete by the end of March, with the specialized construction of the radiation treatment suites on schedule to start mid-April.

To view a video about building safe radiation treatment facilities, visit
nhs.plenaryprojects.com. «