​The extreme complexity of irradiation modes used in external radiotherapy requires advanced and rigorous quality control processes. Aquilab developed a new pre-irradiation beam control method based on a two-dimensional electronic portal imaging device (EPID), traditionally used to check that the patient is in the proper position.

Usually, the beam is checked by irradiating a water tank. Here, the measurements that were once taken in the water are replaced with equivalent data gathered from EPID images of the beam and calculated by the software. To determine whether the method is reliable, the DOSEO platform at List, a CEA Tech institute, leveraged its extensive knowledge of Monte Carlo simulation to find out. The researchers began by validating the conversion model used to translate the signals in an EPID image to the absorbed dose to water equivalent. They then assessed two new statistical image comparison methods to improve the sensitivity and precision of the pre-irradiation beam tests.

The initial results were very encouraging, suggesting that Aquilab’s solution could check beam quality faster (in just tens of minutes instead of several hours) and better than traditional methods, even during treatment. Aquilab will also use the results to obtain the CE label for its software, positioning DOSEO as a leader in the field.