PET – POSITRON EMISSION TOMOGRAPHY

PET: POSITRON EMISSION TOMOGRAPHY

Most used PET radiotracers Izot. Radiotracer Mecanism 18F 18F FDG (90%) Glucidic Metabolism 18F-Fluoro-Dopa dopaminergic Sintesys 18F-Fluoro-misonidazole Tumoral Hipoxia 18F-Uracil (FU) Chimioterapy evaluation (5FU) 18F FLT FluoroTimidin Cellular Proliferation 15O H²O15 Perfusion 11C 11C-Acetat Oxidativ Metabolism (miocardic + tumoral) 11C-Palmitat Miocardic Metabolism (acizi graşi) 11C-Tirozin Tumoral Metabolism 11C-Timidin Cellular Proliferation 11C-Metionin 11C-Colin 11C-Acid-Amino-IsoButiric 11C-Acid-Amino-Ciclopentan-Carboxilic (ACPC) 13N 13N-NH3 (amoniac) Miocardial Perfusion 13N-Glutamat

Coincidence detection Unstable nucleus positron antiparticle of the electron (same charge, opposite semn) electron positronium 2 gamma photons, 511 keV Coincidence detection (interval 10-9 sec.) detector: Bi germanat crystal(BGO) Photomultipliers around PET principle

Desintegration through Anihilation process Anihilation photon g Anihilation electron/positron b- b+ Anihilation photon g Desintegration through positron emission Device

PET: analogs metabolic Glucidic Metabolism Glicolisys in malignant cell The germinating idea of PET: Nobel Prize Medicine Laureat, Dr. Otto Warburg: <The prime cause of cancer is the replacement of the respiration of oxygen by normal body cells by a fermentation of sugar>

GLUT transporters GLUT8 GLUT6

18FFDG (18F-2fluoro- 2deoxi-Dglucose)

PET Indication Miocardial Scintigraphy Tumoral Scintigraphy : pulmonar neoplasm mamary neoplasm cerebral neoplasm ovarian gastrointestinal neoplasia limphoma Head-neck tumors endocrin tumors : thyroidian, carcinoid, pheocromocitoma

Normal 18FFDG PET image

Normal PET and PET-CT images

Pathologic 18F FDG PET images in cancer

Lung cancer

Lung cancer with metastases

Hodgkin lymphoma with metastases

Melanoma

PET-CT images

Imagini PET (18FFDG), CT şi PET-CT normale (secţiuni coronale)

PET + CT = PET-CT