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Radionuclides & Radiation : Tools for Betterment of Humankind. Meera Venkatesh Radiopharmaceuticals Division Bhabha Atomic Research Centre. Radionuclides – What are they?. Unstable nuclides of elements Emission of energetic rays in the process of becoming a different, more stable nuclide
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Radionuclides & Radiation : Tools for Betterment of Humankind Meera Venkatesh Radiopharmaceuticals Division Bhabha Atomic Research Centre
Radionuclides – What are they? • Unstable nuclides of elements • Emission of energetic rays in the process of becoming a different, more stable nuclide • Radioactive rays
Radionuclides - Properties • Emission of Radiation • alpha (), beta () : particulates • gamma () : non-particulate • energetic; varying energies • Transient - non-permanent • concept of half life; varying half-lives
Radiations : , , • energetic • interact with matter to deposit the energy • the radiations are easily measurable at very low amounts - high sensitivity • the material may alter and its properties may change – e.g. polymerisation • the radiation will attenuate after interacting with the material – e.g. its energy reduces, intensity reduces
Some Areas of Impact • Medical • diagnostic, therapeutic, sterilization • Agriculture • food preservation, tracers, mutation • Industry & Hydrology • radiography, tracers, gauging, radiation processing • Research • tracers ...
Radioisotope/Radiation Applications : Basis • Easy detectability : Tracers • Alterations in the material on irradiation • Attenuation in the radiation itself
Easy detectability of radiation • Tracer applications - Medical • Diagnostic in-vivo Nuclear Medicine; • static imaging of organs; • dynamic imaging of organs; • understanding the functioning of vital organs; • delineation of tumours etc.etc. • Diagnostic in-vitro radiometric kits • hormones/drugs/antigens measurement in biological samples
Tracer applications - industries, water management • trouble shooting; hydrology applications; process development/optimisation, monitoring industrial reactions etc. • Tracer applications - laboratory & agricultural tracers; • process understanding; optimisation of manure/ pesticide; fate of the used manure/pesticide etc.
Radioisotope/Radiation Applications : Basis • Easy detectability : Tracers • Alterations in the material on irradiation • Attenuation in the radiation itself
Alterations in the material • damage to living cells, death of living organisms - fungi, bacteria, cancer cell .. • polymerisation of monomers • creation of defects in materials - crystal structure • breaking of very tough materials
Damage to living cells • Fungi, bacteria .. ; food preservation by irradiation; sterilization of medical products by gamma irradiation; blood irradiation • cancer cells ;teletherapy, brachytherapy, in-vivo therapy - radiopharmaceuticals, loco-regional therapy
polymerisation of monomers; • radiation processing of wires, cables, ‘O’ rings etc. • breaking of very tough materials • degradation of polymers, teflon etc. • creation of defects in crystal structure • colouration of diamonds
Radioisotope/Radiation Applications : Basis • Easy detectability : Tracers • Alterations in the material on irradiation • Attenuation in the radiation itself
Attenuation in the radiation • intensity decrease • information about the material - uniformity, thickness, defects etc. • Gamma radiography ; status of/defects in materials • Nucleonic gauges;thickness, level measurements
Which radionuclides or radiations? Selection Criteria • Emission properties • type of radiation, energy • Half life • Chemistry • Feasibility • Cost
Medical use of Radiation & Radioisotopes Diagnostic Therapeutic Radiation processing Teletherapy In-vivo Radiopharmaceuticals Brachytherapy Gamma knife In-vitro radiometric assays Sterilization, Blood Irradiation Polymerized products : hydrogel, drug delivery systems
Radiopharmaceuticals • Molecules containing Radioactivity used in Medicine - for Diagnosis & Therapy • Diagnostic Products • In-vivo • injectibles • oral • In-vitro • Radiometric assays • Therapeutic Products • In-vivo • injectibles • oral • Sealed Sources • Brachy Therapy • Topical Applications
Diagnostic Radiopharmaceuticals • In-Vitro : ‘in-glass’ or outside the body • Radiometric Assays (RIAs & IRMAs) • Nobel prize winning technology (Dr Yalow-1976) • Very useful tool in diagnosing diseases related to hormones; indispensable in pathology labs • More recently use in various areas : Tumor Specific Antigens, viral antigens, drugs with narrow therapeutic index, non-clinical applications • IRMA- Prostate Specific Antigen - Prostate Cancer • RIA-Aflatoxin B1 - mycotoxin - food commodities
Radiometric Assays • Analytical techniques to measure minute quantities of an analyte in a complex matrix • Use of radiolabeled molecule as the tracer • Utility in Medicine, Environment, Food industry etc.
Concentration Substance 10 mmol/L 1 Glucose Albumin 100 10 umol/L 1 Creatinin Iron Immunoglobulin 100 10 nmol/L 1 Thyroxin, Cortisol Progesterone, Testosterone, T3 Estradiol 100 10 pmol/L Insulin Free T3 Endocrinology, Oncology Drug development Pharmacology & toxicology Non clinical fields
Diagnostic Radiopharmaceuticals : in-vivo • In-Vivo : ‘inside the body’ • Static Imaging • Organ size, shape, abnormalities etc. • Thyroid, Liver, Kidneys, Brain, Skeleton, Lungs, malignancies • Presence of nodules, tumours, metastatic lesions, goitre, abcess, shrinkage etc. • Dynamic Imaging • Functioning of the organ, rate, output, defects etc. • Heart, Liver, Kidneys • Infarcted myocardium, hole in the heart, filtration defects in kidneys etc.
Nuclear Medicine – for imaging • Very safe • Non-invasive • No reactions or side effects • minimal radiation dose
Uniqueness of a nuclear scan • X-ray, USG, CT & MRI – give anatomic information. • Nuclear scan provides unique FUNCTIONAL as well as ANATOMIC INFORMATION • A highly sensitive technique; • also known as Molecular Imaging • Available for almost every organ / system
Example: Functioning of heart muscles Typical heart scan - dynamic showing various regions for easy diagnosis of functioning and quantification of results
Static images of thyroidwith Na99mTcO4 Avid Uptake with increased TSH Iodine Deficiency Goitre Normal Lingual Thyroid Avid Uptake with increased T3& T4 Toxicosis Cold Nodule - Rt Lobe
WHOLE BODY BONE SCAN for skeletal metastases in patients with known or suspected cancer. 99mTc MDP Bone Scan Multiple Metastases Ca Prostate Multiple Metastases Ca Lt Breast Normal
Positron Emission Tomography: PET • Recent technology • 18F-Fuloro deoxy glucose (18F-FDG) most widely used tracer for PET • 3D picture of defects, clear, precise • Most often used to find out recurrence of cancers • Also used to image heart and brain to find tissues that are not ‘alive’ (do not take up glucose)
Therapeutic Radiopharmaceuticals • Deleterious effect of ionising radiations on cells/organisms • In-vivo & Sealed Sources • Primarily Cancers; others : hyperthyroidism, radiation synoviorthesis etc. • Historically very old ; non-systematic • Systematic - Old - 131I, 32P • Surge - past 15 years • Forecast : sales 0.5 B USD now to 2.8 B in 2007
Range of particulate radiations 10 a : cell nucleus b : single cell c : few cells d : 100 cells d 1 c Range (mm) 0.1 b 0.01 a Auger e- 5.3 MeV, 0.15 MeV- 1.7 MeV -
Therapeutic Radiopharmaceuticals • Palliative - Bone pain • Radiolabeled phosphonates • 89Sr Chloride, 32P-phosphate, 153Sm-EDTMP, 188Re-HEDP , 188Re-CTMP, 177Lu-DOTMP, 175Yb-DOTMP • Liver cancer treatment • colloids/particulates - through hepatic artery • 166Ho-chitosan, 90Y-glass microspheres, 188Re-Sn colloid • Radiation Synoviorthesis • colloids/particulates : intra articular injections • 166Ho-Hydroxyapaptite(HA), 153Sm-HA, BARC - clinical trials and supply
Example: Treatment of rheumatoid arthritis using a radiopharmaceutical
Brachytherapy • Use of radioactive sources for treatment • Within the tissue • Covering the cancer tissue – like amould • Within a cavity having cancer • Within a vessel to be irradiated
Low Energy Radioactive Plaque Therapy for treatment of Ocular melonoma Tiny rice-sized {0.8mm(OD)x4.75mm(l)}radioactive seeds (15-25 no.) are glued into the gold eye-plaque or seed carrier. A mushroom-shaped choroidal melanoma Plaque is sewn covering the tumour and removed after stipulated dose delivery (2-3 weeks)
Clinical Trials • Sankara Netralaya, Chennai; 10 Patients successfully treated since Sept. 2003; all doing fine. • Product awaiting AERB approval for regular use
Prostate brachytherapy–within tissues . • Prostate cancer is a disease in which cancer cells grow in the prostate. Seed implantation with I-125/Pd-103 seeds (brachytherapy) is a highly effective treatment for men with prostate cancer. • Treatment: • Hormone therapy • Surgery • Radiation therapy
Intracavitary brachytherapy • Encapsulation of small radioactive (137Cs)tubes(40 mCi each). • Location of tumor position. • Implantation of applicator
External beam radiation therapy - Teletherapy • External source • High intensity radiation; 60Co – most widely used • A machine is used to direct the radiation to the tumor (cancer) through the skin.
Gamma Knife Multiple targeting (up to 201 60Co sources; 1 TBq each; circular array) to achieve better dose delivery and low damage to surrounding tissues. • Brain tumors • Acoustic neuroma • Arteriovenous • malformation (AVM) • Trigeminal neuralgia High accuracy, low risk, low complications, low morbidity
Radioisotope Applications in IndustryQuick, easy, clean and cost saving techniques Sealed Sources • Radiation Processing • Radiography Testing • Gamma Scanning • Industrial tomography • Nucleonic Control Systems Radioactive Tracers • Flow rate measurements • Inventory Control - chemical plants • Leak/blockage detection- pipe lines • RTD Studies in chemical reactors • Silt movement studies (harbours)
Radiation processing • Gamma rays/ Electron beams • Medical products sterilization • Blood irradiation • Polymerisation • Hydrogel • Surface curing of materials-cables, wires, O-rings • Processing of sewage sludge • Value addition of gems • Food & Agriculture industry
Radiation processed Hydrogel for use as Burn/Wound Dressing Product patented Commercialized
Sewage Sludge Hygienization Facility Vadodara