Radiochemistry and Radiopharmacy IV

Transcription

1 Radiochemistry and Radiopharmacy IV Compact course held at UFSCAR, September 2013 Ulrich Abram Freie Universität Berlin Institute of Chemistry and Biochemistry Radiochemistry and Radiopharmacy 1. Fundamentals of Radiochemistry. 2. Radiation and Biology. Basics in uclearmedical Diagnostics and Therapy. 3. Positron Emission Tomography (PET) with 18 F Compounds. 4. Single Photon Computer Tomography (SPECT) with Tc. 5. uclearmedical Research for Diagnostics ( Tc, 68 Ga) and Therapy ( 186 Re, 188 Re). 1

2 Radiochemistry and Radiopharmacy 3. Single Photon Computer Tomography (SPECT) with Tc. Tc uclear properties and production uclearmedical chemistry of technetium Classical Tc agents for imaging of skeleton, liver, kidneys and lung Pharmaceuticals for brain imaging Pharmaceuticals for heart imaging Tc uclear properties and production 2

3 Tc uclear properties and production Isotopes and uclides of Technetium uclide eutrons T 1/2 Decay Decay product 85 Tc 42 < 110 ns ß+, p, 17 more nuclides 94 Tc min ß + 94 Mo 94m Tc min IT (0.1%), ß + (99.9%) 94 Tc, 94 Mo 95 Tc h ß + 95 Mo 95m Tc d IT (3.88%), ß + (96.12%) 95 Tc, 95 Mo 96 Tc d ß + 96 Mo 96m Tc min IT (98%), ß + (2%) 96 Tc, 96 Mo 97 Tc x 10 6 a EC 97 Mo 97m Tc d IT (99.7%), EC (0.3%) 96 Tc, 96 Mo 98 Tc x 10 6 a ß 98 Ru 98m Tc µs IT 98 Tc 99 Tc x 10 5 a ß 99 Ru Tc 56 6 h IT (99.99%), ß (0.003%) 99 Tc, 99 Ru 100 Tc s ß, EC 100 Ru, 100 Mo 100m1,100m2 Tc s, 3.2 s IT 100 Tc 101 Tc min ß 101 Ru 21 more nuclides 118 Tc 75 > 300 ns, < 30 ms Tc uclear properties and production Tc 99 Tc pure γ emitter E max = 140 KeV no particle emission T 1/2 = 6 h permanently available (generator nuclide) concentration about 10 9 mol/l weak ß emitter E max = 290 KeV T 1/2 = 2, a available in macroscopic amounts conventional chemistry possible 3

4 Tc uclear properties and production Tc as a metastable nuclear isomer 99 Mo Tc 86 % 66h 14 % Tc Tc 6h Tc 2, a 99 Ru (stabil) Tc uclear properties and production Manufacturing of 99 Mo from Uranium fuel elements Absorption of 99 Mo on a chromatography column 4

5 Tc uclear properties and production 99 Mo/ Tc uclide generator Concentration of the Tc in the eluate of the generator: about 10 9 mol/l Chemical form: pertechnetate, TcO 4 uclearmedical chemistry of technetium TcO 4 Thyroid scintigraphy Asymmetrically increased thyroid gland Increased thyroid by deficiency of iodide 5

6 uclearmedical chemistry of technetium Production of the injectionready pharmaceutical directly in the clinic TcO4 + Instant Kit injectionready Tcpharmaceutical A kit vial contains: Ligand Reduction agent Catalysts + Stabilisors Please remind! Concentration of Tc: about 10 9 mol/l uclearmedical chemistry of technetium Production of the injectionready pharmaceutical directly in the clinic 6

7 Classical technetium radiopharmaceuticals Thyroid scintigraphy, Tcpertechnetate Kidney scintigraphy, TcDTPA TcO 4 HOOC HOOC Liver scintigraphy, TcEHIDA Bone scintigraphy, TcMDP C 2 H 5 H CO C 2 H 5 O O P O OH O O P O OH Classical technetium radiopharmaceuticals Classical Kidney scintigraphy, TcDTPA Glomerular filtration HOOC HOOC A kit vial contains e.g.: 20 mg DTPA 0.25 mg SnCl 2 x 2 H 2 O 5 mg paminobenzoic acid 3.75 mg CaCl 2 x 2 H 2 O Estimated structure of the complex DRAXIMAGE DTPA Costs: about 70$ 7

8 Classical technetium radiopharmaceuticals Classical Liver scintigraphy, TcEHIDA C 2 H 5 H CO C 2 H 5 Costs: about 70$ Classical technetium radiopharmaceuticals Classical bone scintigraphy, TcMDP O O P O OH O O P O OH A kit vial contains e.g.: 20 mg MDP 11 mg aoh 0.13 mg SnF 2 1 mg ascorbic acid Braco MDP Costs: about 70$ 8

9 Classical technetium radiopharmaceuticals Classical lung imaging, TcMAA (macroaggregates from albumin) Different principle: Denaturated protein e.g. human serum albumin) spheres of defined size are treateded with Sn 2+ Reaction with TcO 4 gives labeled aggregates Size of particles controls biodistribution Costs: about 70$ Tc radiopharmaceuticals for brain imaging Basic concept (derived from classical pharmacy) compound must pass bloodbrain barrier Small Lipophilic neutral Transfer to Tc chemistry means to find a solution with coordination chemistry 7th group of the periodic table 8 oxidation states Redox control Charge control by coligands core chemistry o nonradioactive isotope 9

10 Tc radiopharmaceuticals for brain imaging Transfer to Tc chemistry means to find a solution with coordination chemistry [Tc(abt) 3 ] [TcCl 6 ] 2 [TcBr 4 ] 2 [Tc 2 (CO) 10 ] TcO 4 +6 reduction oxidation 0 Tc metal [TcH 9 ] 2 [TcOCl 4 ] [Tc(tmbt) [Tc(C 6 H 6 ) 2 ] + 3 (MeC) 2 ] Tc radiopharmaceuticals for brain imaging TcHMPAO (Ceretec ) TcO 4 + H OH Ligand H HO SnCl 2 O Tc O O H Complex A kit vial contains e.g.: 0.5 mg ligand (only d,l isomer) 4.5 mg acl mg SnCl 2 GE Healthcare Ceretec 10

11 Tc radiopharmaceuticals for brain imaging TcHMPAO (Ceretec ) H H OH HO Costs: about 300$ Tc radiopharmaceuticals for brain imaging Other Tc compound for brain imaging Tc(V) oxo complex Trapping by ester metabolism o stereo isomers Tc(V) oxo complex Trapping by chelate metabolism o stereo isomers Tc(III) complex Trapping by Cl /H 2 O exchange ot routine Tc ECD Tc MRP20 BATO compound 11

12 Tc radiopharmaceuticals for myocardial imaging Basic concept (derived from classical pharmacy) Replacement of 201TlCl Cationic Lipophilic Metabolic activity for retainment Ligand CH3 CH2 C O C Ligand CH3 CH3 TcI complex TcV complex Tc radiopharmaceuticals for myocardial imaging TcI complex A kit vial contains e.g.: 1.0 mg [Cu(L)4](BF4) 2.6 mg sodium citrate 1.0 mg cysteine hydrochloride 20 mg mannitol mg SnCl2 x 2 H2O Brystol Myers, Squibb Cardiolite Costs: about 300$ 12

13 Tc radiopharmaceuticals for myocardial imaging TcV complex A kit vial contains e.g.: 0.23 mg ligand 0.32 mg disodium sulphosalicylate 0.03 mg SnCl2 1.0mg sodium gluconate 1.8 mg ahco3 GE Healthcare Myoview Costs: about 300$ Tc radiopharmaceuticals for myocardial imaging Other Tc compound for heart imaging Tc(III) complex eutral!!! Trapping by Cl/H2O exchange Tc Cardiotec Tc(III) complex Mixedligand compound Metabolic trapping Tc Technecard Tc(V) nitrido complex eutral Trapping by ether metabolism Tc TcOEt 13