Page 70 - Tcexpression2021 - Sept to Dec 2020

NUCLEAR

MEDICINE

he word “Nuclear” conjures all sorts of negative Globally used radioisotope for these procedures is
images in people’s mind nowadays. But PET scans, Tc-99, which is used in almost 85% of nuclear medicine
Theart scan, bone scan and radiation therapy for procedures. Tc-99 (Technetium) is an ideal isotope
cancer are all derived from our deep understanding because
of Radioisotopes and how we could use them safely
and effectively. Radioisotopes are isotopes of elements Metabolic processes can be viewed within 6 hours,
which are radioactive. Lack of knowledge about and it also reduces dosage to the body
radiation and radioisotopes in medicine is common A good emitter of low energy electrons and gamma
regarding diagnostic tools, therapeutic medicines, and rays
equipment sterilisation.
Uses of Radioisotopes Technetium forms tracers that combine with active
biological substances to collect in the tissue or
Diagnostic radiopharmaceuticals organ of interest
Other radioisotopes used are rubidium-82, thallium-201
Our body organs absorb different chemicals at
different rates; for example, Iodine is absorbed more chloride, and fluoro-deoxy glucose (FDG) incorporating
by the thyroid. A small amount of a specially created F-18 respectively for PET imaging by strontium-82,
radioisotope is injected into the body. These get Myocardial perfusion imaging (MPI) for coronary artery
localised in specific organs, and the scans can detect disease and PET imaging.
that organ’s dis/functionality. The technique can Nuclear medicine therapy
measure blood flow to the brain, functions of liver,
lungs, heart, kidneys, bone growth assessment, etc. Cancerous growth can be eliminated/reduced by
using radiations. External irradiation is performed
This procedure’s key element is that the radioisotope
used should have a short half-life, a good gamma using a gamma beam from a radioactive cobalt-60
emitter, must be removed from the body through the source by focusing on the cancerous tumour region.
normal biological process. The dose obtained from this Internal radioisotope irradiation or Brachytherapy is
should be minimal. used generally for thyroid and breast cancers wherein

70 TCExpresssion