Since the 90ties the PET (Positron-Emission-Tomography) has gained increasing significance in the clinical diagnostics of cancer diseases and in early diagnosis of the Alzheimer’s disease. Oncological PET is based on the principle already discovered by Otto Warburg in 1927. It says that tumours have an intensified metabolism and thus have an increased sugar uptake and can thus be distinguished from malignant tumour tissue. Using weak radioactively marked glucose (sugar) the Positron-Emission-Tomography can track, and subsequently quantify the glucose metabolism within a patient without physical intervention. Functional images can be created from the data obtained. In most oncological problems the PET is absolutely superior to usual examination procedures, such as Computer-Tomography, nuclear spin resonance tomography, ultrasonography, tumour marker determination and clinical examinations. Thus PET detects e.g. even more tan 80times as much cancer in an early stage than examinations in the normal preventive medicine. PET is superior to all other methods in the search for unknown primary tumours or when distinguishing between a normal scar after a cancer operation and a cancer relapse.
Furthermore, PET can already diagnose after a short time period, whether chemotherapy will be useful for a patient suffering from cancer, so that, if necessary, a new therapy concept can be created. Thus side-effects of an ineffective chemotherapy can be avoided and costs can be saved.
As there already are medicaments that can delay or stop the development of the Alzheimer’s disease, the use of PET in the early diagnosis of Alzheimer’s is very important and most helpful.
In the new piece of equipment both a PET and CT machine of highest diagnostic quality have been combined. The combination of both allows a reduction of whole body examinations currently 60 minutes to 15 minutes with a much higher quality. Through the combination of both morphologic and metabolic information the significance of the separate procedures increases. A significant improvement of sensitivity as well as specificity is achieved. On the one hand the combination allows an exact anatomic assignment of conspicuous PET findings; on the other hand an improved assignment of marginal CT findings is made possible. Besides this, diagnostic findings of both processes that are not conclusive on their own, can give a conclusive answer in combination.
Altogether, PET is an non-invasive, imaging examination procedure with enormous potential and possibilities in cancer diagnostics, which has only in recent years been implemented in clinical routine. In the USA, as well as in Italy, Switzerland and Belgium, the procedure has already been accepted by the FDA and is paid for by compulsory health insurance funds. In Germany this applies only restrictedly PET examinations for patients suffering from lung cancer (also see News: PET for lung cancer now convention medical GKV service). This actually is the case, although a high number of original publications considering the topic PET/CT since 2004 made by well-known magazines, such was “New England Journal of Medicine” (Juweid and Cheson 2006), “Radiology” (by Schulthess et al. 2006) and “British Journal of Radiology” (EIL 2006), have declared the PET/CT in compendium works as the “Golden Standard”. A corresponding articles can be found in multidisciplinary German-speaking magazines, such was “Deutsche Medizinische Wochenschrift”, DMW (Bamberg, Diehl et al. 2006) and the “Deutsches Ärzteblatt” (Bockisch et al. 2006).
The detection margin of PET is placed in the area of 105 to 106 malignant cells. A tumour of 106 cells has a diameter of about 1mm (European Journal of Nuclear Medicine Vol.33 No6). PET can, according to this, detect malignant processes before morphologic changes occur.