POSITRON EMISSION TOMOGRAPHY MUDr. Igor Černý Clinic Of Nuclear Medicine FN Brno History of PET •1952 - first PET system - Brownell, Aronow •1962 – firts more-detectors system •1968 - first PET tomography system (PC I) •1971-6 first PET commercial system (PC II) •2001 first commercial PET/CT scanner •2010 first commercial PET/MRI scanner • Proton neutron + positron (+)  neutrino()  + 11C 11B Princip Of PET  + emission Atom sestává z jádra obklopeného elektrony. V jádře jsou pozitivně nabité protony a neutrony. Stabilita jádra závisí na relativním množství protonů a neutronů. Pozitronové radionuklidy se vyznačují tzv. beta-plus rozpadem, kdy se proton transformuje na neutron, pozitron (beta+) a neutrino. •Beta emission •Beta+ - reaction positron with electron – positron annihilation – two amounts of gama radiation (energy 511 keV) anihilace.gif Positron emission tomography – PET camera žImaging: two detector elements on opposite sides of the subject are used to detect paired annihilation photons(gama radiation) ž ž20 000 detectors in ring, 30 rings ž žDetector materials: BGO (bismuth germanate) or LSO (luteciumortosilicate), APD –avalanche photodiode detector ž žElectronic collimation – opposite coincidence window 10 nanosec. ž žSuperior sensitivity and spacial resolution that SPECT – 3D scintigraphy • ž PET possible types of detection Radiopharmaceuticals •18FDG – aerobic glycolysis • •18FLT – fluorothymidin - – cell proliferation • • Na18F - fluorid sodný – bone renewal • •18Fcholin, 18F Fluciklovin, 68GA PSMA – Prostatic cancer • •18FDOPA, 68Ga DOTA – NET • •18Fflutemetamol – Alzheimer disease radionuclide – 11C (half time -20 min) ,68Ga (67 min), 15O (123 sec), 18F (110 min) Ligand – body substances, most common FDG (fluorodeoxyglucose) Hybrid systems žCamera system piles from two independent systems – scintigraphy camera and CT or MRI scanner ž žFusin pictures from both systems – information on function organ gained scintigraphy methods are inosculation with anatomical photos from CT or MRI PET/MR/CT https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcTaN1YXUBfwiPRChFDS7vWkc1np_SzripoD-IPWsqC2wlI 2uu3s PET/CT PET/MR CT - Topogram (scout) - CT scan (1 min) PET/CT - 20min PET - Brain (10 min) - Heart (10 min) - Body (20 min) Imaging protocol PET/CTx PET/MRI Patient - Fast 4 hrs prior to exam - Inject tracer - Start scan 60 min later PET/MRI – 40 – 60 min PET - 15 min MRI - First part simultaneously during PET scanning (T1, T2 and DWI) - second part after PET scanning – other needed sequences (25-40 mins) ADVANTAGES PET •Skull to mid thigh in 15 mins. • •Functional imaging • •High sensitivity • •No adverse reaction in last 30 years PETxSPECT •As well three-dimensional vision as with SPECT – 3D scintigraphy • •30x higher sensitivity than SPECT • •Better resolution than SPECT • •Possibility of quantification of radiofarmaceutical • Advantages and disadvatages PETMR x PETCT •Advantages: –No radiation load x CT –PETCT – mean dose 5 - 23 mSv, PET 3-5 mSv –Excellent tissue contrast MR –Possibility to combine with more advanced techniques such as perfusion, DWI, angiography, spectroscophy – •Disadvantage: – the length of the examination – basic MRI contraindications • Most common PET Tracer: FDG Glucose FDG Glucose FDG Glucose-6-P FDG-6-P Plasma Cell 18F-fluorodeoxyglucose (FDG) is taken up by cells proportionate to their metabolic rates Hexokinase FDG Glucose Glucose 6-phosphatase Glucose 6-phosphatase G6P Glycolysis NEOPLASTIC CELL 1 2 3 FDG-6-P Indication •Oncology (staging, control of treatment effectiveness, monitoring after treatment) • •Inflammation (investigation of inflammation origin, vasculitis, sarcoidosis, inflammation of the heart, suspected inflammatory changes around implanted foreign materials • •Rheumatology (eg polymyalgia) • •Cardiology - myocardial viability • •Endocrinology (detection of hyperfunctional parathyroid glands) • •Non-tumorous pathology of CNS (Neurodegenerative diseases) Problems and Pitfalls • False positive findings Normal physiology Granulomas and other infections Tumor histology(renal carcionoma) Lesions smaller than 6-8 mm Diabetes/Non-fasting patients • False negative findings Physiologic Uptake: Brown Fat •Effective chemotherapy decreases FDG accumulation in tumor cells. • •The longer time distance PET / CT examinations from CHT - the higher the sensitivity of the method (recommended at least two weeks) • •Evaluation of FDG-PET in the irradiated area can be exacerbated by several months (the gap is suitable PET / CT examination by RT 3 months) • • PET/MR on our department •Instalation: June 2016 –2016 – 111 patients 2017 – 858 patients –2018 – 1389 patients Colrectal carcinoma – 22% Liver tumors– 17% Gynecology tumors– 11% Lymfoma – 7% Common body tumor protocol – 7% Lung carcinoma – 5% Neck carcinoma – 5% Brain FLT – 4% Brain FLT – 3% Other tumors body protocol– 2% Abdomen tumors – 2% Whole bofy myeloma and melanoma – 2% Brain Demetia – 2% Prostatic cancer Cholin – 2% Brain other – 1% Parnasal sinusis tumors– 1% Other– 7% • Sevcikova_WB_CT_vyrez Sevcikova_WB_fuze_vyrez Sevcikova_WB_PET_vyrez Big metastasis in liver, unknown origin PET/CT – origin tumor Of colon CT PET/CT PET Září 2005: MM, stp. Dvou autologních transplantacích periferních bb., chemoterapie, zvětšení levostranných LU na krku, cytologicky plasmocelulární infiltrace. Leden 2006: relaps extramedulární v uzlinách vlevo na krku a v levé axile, navíc i ložisko v obl. pravé klíční kosti. Atypická situace – klasické známky relapsu – paraprotein, lehké řetězce a další jsou v normě, v KD nebyly rovněž infiltráty myelomu, vše je extramedulárně, probíhá radioterapie na oblast zvětšených LU a probíhá rovněž chemoterapie. 88* female •non hodgkin lymphoma 11/2017 3/2018 after treatment - Complete regresion 5/2018 recurrent disiese 8/2018 control after autologous transplantation PET PET PET Chest Xray ®Difficulty with emptying ®rectoscopically in 12 cm tumor infiltration Fúze T2 T2 • PET Fúze DWI T1 - nativ T1 – k.l. art. T1 – k.l. PV T1 – k.l. hepatospec. 48* male 18F Cholin •Hepatocelular carcinoma – grade 1 DWI • PET T1 – k.l. art. T1 – k.l. PV PET – 68GA DOTA SPECT - Octreotid female 40* •Febrile state of unclear etiology •CRP 142 PET T1 – k.l. T2 64* - muž •Prolonged myalgia • •Swelling and stiffness of tiny joints of the hand • •CRP elevation • •polymyalgia rheumatica x vasculitis •Two-sided symmetric picture of inflammatory changes of joints and muscle insertions (metabolic activity in the area of the joint capsule + intraarticular effusion PET T2 - FS T2 - FS 18FLT – male 99* •Pilocytic astrocytoma of mesencephalon T1 - nativ T1 – c.a. male 39* – –since 2015 the developing cognitive deficit T1 T2 PET Fúze T2* DWI Typical PET / MR image of Alzheimer's dementia Mutually symmetric atrophy and hypometabolism of parietal lobes (especially precuneus) Later bilateral mediotemporal atrophy and hypometabolism There is no reduction in metabolism in the basal ganglia 18F Flutemetamol •Detection of β amyloid deposits •sensitivity 64% specificity 69% (1) •A negative finding significantly reduces the likelihood that it is Alzhemer's disease or its preclinical stage (1) (1)Marcus, Charles, Esther Mena, and Rathan M. Subramaniam. "Brain PET in the diagnosis of Alzheimer’s disease." Clinical nuclear medicine 39.10 (2014): e413. (2)Martinez, Gabriel, et al. "18F PET with flutemetamol for the early diagnosis of Alzheimer's disease dementia and other dementias in people with mild cognitive impairment (MCI)." The Cochrane Library (2017). female 44* –patient with dementia of mild to moderate degree –Expression disorder T2 PET T1 Cerebral bood flow - ASL DWI Fúze PET / MR image of semantic dementia Atrophy affects the ventral portion of the temporal Extension of the temporal corner of the lateral ventricle to the left Asymmetric atrophy of the left hippocampus Cholin •Adenokarcinoma of prostatic gland •PSA 29,7 ng/mL PET T1 T1 44* male - FLUCIKLOVIN 18F •After prostatectomy for cancer • •biochemical relapse • •negative findindg on Cholin PET/CT • PET Prostatic gland - PSMA 68Ga Male 66 years after prostatectomy slow increase in PSA now 0.17 ng / ml, patient with negative finding on PET with Choline PET T2 T2 Hyperfunctional parathyroid glands •PET cholin 18F - sensitivity 95% –Treglia, Giorgio, et al. "Diagnostic performance of choline PET for detection of hyperfunctioning parathyroid glands in hyperparathyroidism: a systematic review and meta-analysis." European journal of nuclear medicine and molecular imaging (2018): 1-15. – – – •99mTc-MIBI SPECT – senzitivity 58 % –Caldarella, Carmelo, et al. "Diagnostic performance of planar scintigraphy using 99m Tc-MIBI in patients with secondary hyperparathyroidism: a meta-analysis." Annals of nuclear medicine 26.10 (2012): 794-803. Female 55* Primyry hyperparathyreosis Negativ MIBI a US PET Fúze T2 Thanks for your attention