(The biennial Physics for Health conference was held in Geneva last week. The conference kept an intersting and easy-to-read series of blog posts, one of which is reproduced below. To read the whole blog, click here.)
How can the combination of different devices and techniques improve treatment and diagnosis? This is one of the main issues that medical imaging is going to face from now on, as technology, along with the development of adequate software, made it possible to combine different imaging systems in the same apparatus.
It was 1994 when CT scan combined with PET was first considered. The very first attempt consisted of a PET scan followed by a CT scan. A specific software allowed to overlap the images, thus adding the data collected by PET to the anatomical details of a CT scan.
“Before that date, nuclear medicine, was more likely unclear medicine, and that was not only due to the swap of the first two letters of its name,” Professor Ratib quipped. As a matter of fact, the images produced with the sole PET are difficult to decode, because they only show indistinct spots of drug uptake, which cannot be precisely located.
“We knew that the tumour was there, but we had no information regarding its real position. This means that PET alone cannot give enough information to the surgeon or the physician, who are unable to select the proper treatment or intervention.” Which is a crucial point. According to the data presented, up to 50% of the treatment protocol may need to be adjusted after a PET-CT scan. Many patients in fact today receive a correct treatment because of the use of hybrid technologies.
The next ambitious goal is to combine PET with MRI, which offers two main advantages: an amazing quality of the visualisation of soft tissues details, and (contrary to the CT scan) the absence of patient irradiation, which is especially important in paediatrics cases “You don’t want to irradiate a growing child brain," Ratib said.
Hybrid technologies are known since almost 20 years, but nowadays we possess the knowledge and technology to develop accurate and innovative devices that can help clinicians to deliver an optimal treatment, thus augmenting the survival chances.