|New perspective in high tech radiotherapy planning using РЕТ/СТ images
(Radiation oncologist’s view on PET/CT usage)
- Hadjieva, N. Bildirev, Il. Koleva, Z. Zahariev, V. Vasileva,Е. Еncheva, B. Sultanov
Biological images provided by 18F-FDG РЕТ in combination with structural X ray picture currently offer the most accurate available information on tumour staging, curative antitumour effect for prognosis, impairment of organ function after treatment, as well as primary tumour detection in unknown primary metastatic disease. The authors as radiation oncologists critically have analyzed numerous clinical trials and two guidelines to prove PET/ CT benefi t in radiotherapy practice. At present they found lack of scientifi c evidence to confi rm that patient outcomes are superior as a result of the use of PET in RT planning. PET/CToffers a best image for tumour delineation only in some cases
of lung cancer, mediastinal lymph nodes and malignant lymphomas. 11С metionin РЕТ adds additional information onpostoperative MRI image for brain tumours. Infl ammation aspostradiation phemomenon, as well as physiological organ movements leads to false-positive PET signal. High tech radiotherapy methods require delineation on precise imagesgiven after multidisciplinary team expertise – a practice thatis possible only in clinical trials. These unsolved problems have raised many ethical challenges in medical, scientific and social aspect, if wide and routine use of FDG-PET и РЕТ/СТ is advocated.
Key words: 18 F-FDG PET. PET/CT. 11CMET-PET. RADIOTHERAPY DELINEATION AND PLANNING. FALSE-POSITIVE PET
SIGNAL. MULTIDISCIPLINARY EXPERTISE