A radioactive bunker in the bowels of the hospital

Physicists at health centers control the security of radiology rooms, authentic radioactive shelters with huge walls and strict protocols.

They look like more or less normal rooms, but they are real radioactive safety bunkers of a category only below nuclear power plants. Radiotherapy rooms save lives, but the levels of radiation they have to produce to eliminate malignant cells in the human body make them critical facilities. Built in the middle of hospitals through which thousands of people pass every day, they are surrounded by infrastructure, technology and protocols that are strict to the extreme. The objective is to guarantee the safety of patients, workers and other people in the health center.

To achieve this, physicists are the key figure. It is a specialty that a few decades ago did not exist or remained somewhat cornered in hospitals, but which is now essential. They are specialists in hospital radiophysics, radiation experts who are directly monitored by the Madrid Nuclear Safety Council.. José Antonio Font is the head of the Hospital Radiophysics service of the Miguel Servet Hospital from Zaragoza: “Here we want to kill cells, but to do so we need brutal doses of radiation. If we had an error, such as a worker being locked in the room, we would have a serious problem,” he points out.

Safety starts with the design of the rooms. On some occasions, they can be drawn from scratch on a plan, as is the case with the new hospital in Teruel. In others - the majority - it is necessary to adapt existing spaces in health centers. Not just any corner is worth it. The bunkers have to have earth underneath them, so they are always in the basement of the buildings. They require a minimum space of 40 square meters plus the thickness of the walls, which ranges from 1,5 to 2,5 meters.. The same is needed for the ceiling, which means that in places like Servet some upper floors of the radiotherapy rooms are unusable, since two meters of concrete 'mattress' had to be installed, which has eaten up the rooms.

When you want to build a room, the Council has to authorize the project, and the radiotherapy machine does not enter until it has its approval. And before being used with patients, Madrid inspectors come with their detectors to check that the radiation levels are adequate. As Font says, both inside and outside these walls “zero radiation does not exist.” 

The level of exposure of workers and patients is higher than that of a normal person, but they are far from the parameters that are beginning to be worrying. To verify that this is so, All employees carry a personal dosimeter, a small device known as 'the cookie' because of its shape and packaging.. It is a device with thallium plates in which the radiation causes a change, which makes it possible to measure every month whether the levels are adequate or not.

Then, on a day-to-day basis, physicists make daily checks on the operation of the machine. If deviations greater than 2% are seen with respect to what was planned, the scheduled sessions are suspended until the incident is resolved.. Even manufacturers, from their headquarters, monitor performance remotely and notify if they detect any problems.

The ultimate goal is to avoid the slightest failure, as this can have terrible consequences. The example of fatality was experienced in Hospital at the end of 1990, when about thirty patients received radiation doses much higher than they should have, which caused the death of several of them in what is considered one of the most serious radiological accidents in Europe. Since then, protocols and regulations have been significantly changed to reinforce the total security of the facilities.

Hospital physicists are also responsible for carrying out chemical dosimetry of patients, which are virtual preparations of the radiotherapy treatments they are going to receive. The doses prescribed by doctors are assessed and planning is made, the design of which can last from a couple of hours to a whole week, in the case of the most complicated cases: “We have to kill the tumor cells, but if they are going to be damaged other healthy organs, it cannot be applied,” says Font.

Source: Heraldo de Aragón