"With this new PET-CT we are able to detect lesions that until now were practically impossible to identify with equipment of these characteristics," says Dr. José Ángel Richter, director of the department of Nuclear Medicine of the Clínica Universidad de Navarra. The hospital recently acquired new multimodal equipment that combines PET (Positron Emission Tomography) and CT (Computerized Axial Tomography of conventional radiology) technology. For the Clinic, which already had a PET-CT scanner with similar characteristics, the performance of this new device "allows it to considerably improve the possibilities of detecting a tumor lesion," emphasizes Dr. Richter.

 
This is the first equipment of these characteristics installed in Spain, whose most relevant advantages include a very high resolution and, therefore, a diagnostic precision superior to that of the images obtained up to now, as well as a greater speed in the performance of the procedure. Thanks to this technological development "the new PET can multiply the possibilities of detecting small-sized tumor disease", emphasizes Dr. Richter.

Given the characteristics of the new equipment, its main purpose will be research. "Its use is mainly intended for employment in clinical trials, although the development of all this research work could have repercussions on the care of patients who need to undergo programs of study PET", he points out.

Specifically, the acquisition of the new equipment was made possible thanks to financial aid funding in the form of a reimbursable advance, granted last year to the Clinic by the Ministry of Science and Innovation. The financial aid is part of the 2010 call for proposals corresponding to the "subprogram of actions to boost the researcher and technological environment of the National Health System", the purpose of which is the acquisition of a PET-CT "for clinical trials and clinical research ". The resolution was regulated jointly by the administrative office of State of research and by the high school of Health Carlos III. The advance payment represents two thirds of the total financing of the equipment acquired by the Clinic.

PET technology

The goal PET technology is mainly aimed at the diagnostic imaging of oncological disease and neurodegenerative pathology. Its modus operandi is based on marking molecules or metabolic substrates with positron-emitting isotopes which, administered in the form of radiopharmaceuticals to the patient before performing test in the tomograph, will make it possible to observe the suspected disease.

Through the use of different radiopharmaceuticals, PET technology is able to obtain a diagnosis of certain pathologies in a very specific way, stresses Dr. Iván Peñuelas, director of the Nuclear Medicine Radiopharmacy Unit, which is part of the Clinic's Nuclear Medicine GMP (Good Manufacturing Practice) laboratory (Good Manufacturing Practice). In this regard, the specialist explains that,"if, for example, the suspected diagnosis were hepatocarcinoma, the drug employee should be different from the one used if the diagnosis to be determined were Parkinson's disease".

As a fundamental complement to the latest generation PET-CT equipment, for the last two years Clínica Universidad de Navarra has had the aforementioned laboratory GMP which, together with the pre-existing radiopharmacy facilities, has enabled the hospital center to produce up to 17 different radiopharmaceuticals specifically for the diagnosis and research of numerous pathologies. It is the only Spanish hospital center with a production capacity of this kind.

programs of study dynamic

Doctors José Ángel Richter, Mª José García Velloso, Macarena Rodríguez and Javier Arbizu with the new PET-CT equipment.

Photo: Manuel Castells

An improvement over the previous PET-CT scanner is that the new scanner adds the possibility of performing dynamic, not only static, programs of study scans. "These are specific programs of study necessary in the examination of certain pathologies, such as Parkinson's disease," says Dr. Richter. These programs of study consist of observing the behavior of the incorporation dynamics of radiopharmaceuticals in certain diseases. "This strategy is particularly useful at research. It allows us to observe how the radiopharmaceutical administered to the patient is incorporated into the tumor, while at the same time quantifying the amount of radiopharmaceutical that arrives. We are thus able to observe the behavior of the radioactive drug from a dynamic point of view," the specialist explains.

Better quality and shorter scanning time

The main clinical advantages of the new equipment are centered on an improvement in the resolution obtained and, therefore, in the quality of the image, "which allows a much higher detectability of the disease than usual. This is the reason why with the new PET-CT we are able to detect lesions that were previously very difficult to identify," emphasizes the physician.

By way of example, Dr. Richter details the characteristics of the new equipment. "The previous PET-CT equipment is capable of detecting lesions of up to 8 or 9 mm. Below this size, identification was not easy. The new PET-CT equipment can detect disease up to 4 mm in size". This advantage is based on the better spatial resolution offered by the current device.

The reduction in scanning time is another benefit of the new scanner, a feature that results in greater patient comfort. As described by director of Nuclear Medicine, the new PET offers a much higher sensitivity than the previous one. In addition," he adds, "the scanning field that the new PET scanner is capable of covering is wider. That is why, with the current equipment, the study time can be reduced by almost a third. Thus, if with the previous equipment a full-body study -following the usual protocol of the Clinic's Nuclear Medicine specialists- took about 20 minutes, now a similar scan can be performed in about 7 minutes. Although the capacity of the new device would make it possible to reduce this scanning time, "our intention, however, is to establish an adequate balance between the quality of the diagnostic study and the duration of the scan," the specialist warned.

The current equipment thus offers"better quality in less time. This translates into better diagnostic results that provide greater safety and reliability in the clinical management of the patient and possibly in the therapeutic results. In short, the new equipment offers the specialist more and better information," Dr. Richter said.