Potentialities of Combined PET and CT in Diagnosis of Glial Cerebral Tumors

Trufanov G., Dergunova N., Boykov I.

Medicomilitary Academy, Saint Petersburg, Russia

 

The research goal was to study potentialities of combined PET and CT examination (PET-CT) in revealing and differential diagnosis of glial cerebral tumors.

Material and Methods. We examined 62 cases. The study was carried out with applying the Biograph PET-CT scanner (Siemens). All the patients underwent spiral CT with I/V bolus enhancement. Subsequent PET examination was carried out after administration of 150-200 MBq of 180-fluordeoxyglycose (FDG).

Results. The obtained data allowed to make a conclusion on presence of high-grade and low-grade glial tumors in 40 and 22 cases respectively.
High-grade glial tumors (glioblasyomas, anaplastic astrocytomas) were characterized not only by a typical CT-picture, but also by some certain PET-signs: an area of extremely considerable accumulation of a radiopreparation in the brain substance, which was 4-6 times greater than normal indices. This area had loci of reduced glucose metabolism, corresponding to necrotic zones. Besides, it was surrounded by a zone of reduced accumulation, being a reflection of paratumorous edema.
PET-signs of low-grade glial tumors included an area of reduced or unchanged metabolism of 180-FDG. It was surrounded (especially in case of fibrillar astrocytoma) by a wide zone of low accumulation of a radiopreparation, corresponding to paratumorous edema.

Conclusion. Thus, one can conclude, that combined PET-CT examination is an up-to-date and highly informative method of radiodiagnosis, permitting to reveal and differentiate cerebral masses.