Radiation leaked from cancer treatment room at Monash Medical Centre in Melbourne, documents reveal

Monash Medical Centre has been scolded by the government for providing incorrect information about the thickness of a ceiling in a cancer treatment room. (ABC News: Danielle Bonica)

A cancer treatment room of a major Melbourne hospital has been leaking radiation, with authorities rebuking the facility for providing misleading information about the safety of the space.

The Monash Medical Centre in Clayton had to temporarily shut down its thyroid cancer treatment room, where radioactive iodine was administered, after discovering that concrete slabs separating the building’s floors were much thinner than was originally believed.

The oversight meant that workers in other parts of the hospital were not shielded from radiation.

The hospital was forced to close and lock the offices above and below the treatment room, and the situation sparked a scolding from Victoria’s health department, which hospitals apply to in order to use radiation treatments.

In 2017, Monash Health applied to the department to use radioactive iodine in the treatment room, telling health bureaucrats the concrete slabs were 40 centimetres thick.

But in reality, the concrete was actually 14cm thick, meaning that radiation was able to come through the ceiling and into the office on another floor.

In an email released under freedom of information laws, the department said the hospital’s application appeared “to have provided false and/or misleading information”.

“The shielding and construction of the treatment room does not appear to be sufficient, and is not as described to the department in the 2017 application,” the email said.

“In particular … the application advised … the floors above and below room 44N-02 were constructed of 400mm concrete,” the email said.

“Monash Health have advised the department that this is not correct.”

In response to the department, Monash Health’s former chief executive Professor Andrew Stripp pledged to find “short-term and long-term solutions to this issue”.

He said the hospital believed no one was exposed to unsafe levels of radiation.

“We believe that no individual has been exposed to radiation exceeding 1 mSv per year,” Prof Stripp said.

“We want to assure you that we are taking this matter very seriously and are committed to resolving it promptly and effectively.”

Radiation is measured in millisieverts (mSv).

On average, Australians are already exposed to 1.7mSv of background radiation each year from natural sources like soil, rocks and their diet, which is equivalent to 75 chest X-rays.

The public limit of radiation exposure per year is 1mSv, according to the Australian Radiation Protection and Nuclear Safety Agency.

At this level, there is no evidence of any health effects, according to the agency.

Cancer treatments limited during investigation

It is still unclear how Monash Health became aware that radiation was flowing into other parts of the hospital, but the situation was first uncovered in March.

Internal health department correspondence revealed the hospital contacted authorities after it discovered the concrete slabs separating the thyroid cancer room were “not as expected”.

“Monash Health have identified that occupants of areas above and below the treatment room might have approached (or exceeded) the relevant dose limit,” an internal email said.

How the hospital addressed the radiation safety issue in the long run remains unclear, with Monash Health not answering direct questions.

In a statement, a Monash Health spokesperson described the incident as a “potential minor safety issue”.

“A thorough investigation, jointly undertaken with the Department of Health, was immediately done and found that there was no evidence that the health and safety of patients and employees were at risk,” a spokesman said.

In response to the radiation breach, Monash Health temporarily closed offices above and below the treatment room in April and moved radiation treatments to weekends.

The hospital put up signs on offices containing the radioactive symbol and the words “do not enter”.

The room, which is on ward 44, has since re-opened, with Monash Health saying it was now safe to use.

A doctor who spoke to the ABC anonymously said that eight months after the incident, offices near the room were still being partially shut, forcing staff into another nearby office.

“The main problem for me with regard to the issue is … I’ve never received an estimation of the risk of radiation exposure,” the doctor said.

“We’re only allowed to use it [the office] three days of the week when there’s no radioactive treatment occurring.”

The Department of Health said no one was exposed to levels “that would be of concern”.

But that response has been met with scepticism from the doctor.

“Now the usage of the space has been restricted, I think that speaks to the magnitude of the risk here,” the doctor said.

“Before this year, this space has been used freely … there have been young staff members, old staff members using it without restrictions.

“Have they been informed about the risks, whether it’s minor or not?”