It deals with basic in radioactivity , measurement and application

1. By
Dr.N.Gopinathan M.Pharm Ph.D
Assistant Professor
Faculty of Pharmacy
Sri Ramachandra
Medical college and Research institute ( Deemed University)
Chennai, Tamilnadu India.

2. Radiopharmaceuticals are
the radioactive substances
or radioactive drugs for
diagnostic or therapeutic
interventions

3. • A version of a chemical element
that has an unstable nucleus and
emits radiation during its decay to
a stable form.
• All isotopes are not
radioisotopes.

5. • Technetium 99mTc : possesses a relatively short half life
of 6 hours , which allows administration of higher
amounts of activity for faster and clearer images while
exposing the patient to a low radiation dose. it offers an
abundance of gamma photons for imaging
• 99mTc exametazime- cerebral perfusion radio labeling
• 99mTcmacroaggregated albumin- pulmonary perfusion
• 99mTcmedronate- bone imaging
• 99mTcpertechnetate- imaging of thyroid salivary glands,
• 99mTcsulfurcolloid- imaging of reticulo endothelial
system bone marrow

6. Isotope-same atomic number but
different mass number are called as
isotope

7. Radio isotope
An element that has unstable nucleus
and emit radiation during its decay to
a stable form eg. tritium

8. • Atom whose nuclei have specific number of
protons and neutrons.
• An chemical element that has unstable
nucleus and emits radiation during its decay to
a stable form.

9. • Stable nuclides are not radio active they
remain unchanged for an indefinite period.
• Unstable nuclides are radioactive and they
emit alpha, beta and gamma

12. • The phenomenon by which one nuclide is
spontaneously transformed into another
nuclei with emission of energy in the form of
radiation.
• The nuclide which undergoes spontaneous
nuclear reaction is called as radioactive
• During spontaneous decay, the ratio of proton
to neutron change after one or more decay
process a stable nucleus is formed.

14. • Cyclotron in 1930
• Clinical application of artificial radiation in 1938
in university of california
• In 1949 radioactive is used in treatment of neck
tumor by professor david smithess.
• In 1950 , large scale production of radio isotope
• in 1965, nuclear medicine technology
• single proton emission tomography 1980.

15. All isotopes are not radioactive
unit of radioactivity - curie

16. • It is made up of two protons and two
neutrons. They are same as helium.
• when a nucleus emits an alpha particle, its
atomic number decreases by 2 and its atomic
mass decrease by 4.
• It is slow and heavy.
• It has low penetrating power just can stop
them with a sheet of paper.

17. • It is a good ioniser.
• It cannot penetrate skin but in a close
proximity to cells [ lungs] cause serious
hazards.

18. • It is negatively charged having the mass of an
electron.
• It moves faster because of its velocity 10.9
times the speed of light.
• when nucleus emits beta radiation atomic
mass is unchanged whereas atomic number
decreases or increases by one.
• It can be stop with sheet of aluminum.

19. • Types
• negatron β-
• Positron β+
• The position is identical with negatron in all
aspects its charge.It is also called as
antiparticle of electron.
• Beta particles are used as therapeutic agent.

21. • It is a wave not a particle.
• It is electromagnetic but alpha, beta or
particulate.
• It is emitted due to nuclear de-excitations.
• The excited nuclei have more energy; they
tend to lose excess energy returning to ground
state by emission of gamma radiation.

22. • It can cross easily up to 25 cm of
tissue.
• They have no mass and no charge.
• It has high penetrating power.
• It can be stopped with lead.
• It is mainly useful for diagnosis.

23. • Gas ionisation
• Geiger muller
• Proportional
• pulse ionization chamber
• scintillation method
• The method chosen for measurement of radio
activity depends upon penetrability of
radiation and the extent of energy dissipation.

25. • Radiation cause ionization of gas molecules when
it pass through gases which leads to emission of
electron which in turn reveals the changes in
electrical current.
• It is available in various size and shape. it contains
a chamber with 2 electrode kept at two different
electrical potential.
• The chamber is filled with gas. Measuring device
is attached to chamber indicates the flow of
electric current when the radiation passes to gas
molecules and leads to ionization.

27. • It is modified type of ion chamber
• A small amount of radioactive material
is analyzed by placing inside active
volume of the counter.
• The steady flow of gas Argon with 10 %
methane burged into chamber.
• Steady flow of gas is maintained during
counting. it is mainly used to count low
energy alpha and beta particle.

31. • Ion are produced by direct ionising effect
of radiation on gas molecule in the
detector. It is the most popular radiation
detector which is used to detect alpha,
beta and gamma radiation. it has 100%
efficiency for beta particle but 1 % for
gamma radiation.
• It consist of central wire anode
surrounded by cylindrical cathode [ silver
coated glass tube or brass cylinder.

32. • Two electrodes are enclosed in a gas
tight envelope filled with a argon gas
[ 80 torr pressure ], methane or
ethanol [ 20 torr ] or chlorine [0.08
torr].
• Point of entry of radiation contain a
coin made up of mica about 2.5 cm
diameter.

33. • when a ionising radiation enter the active
volume of Geiger muller counter collision
between radiation and gas takes place which
produce ion pair. These ion pair migrated
towards the appropriate electrode under the
voltage gradient due to this high potential
gradient, electrons get sufficient velocity to
produce new pair of ions .

34. • The process is repeated several times, each
ionising particle that enters the active volume of
the counter gives rise to avalanche [ sudden large
amount ] of electrons which travel towards the
central anode and strike the anode. spread the
ionisation throughout chamber. these process
produce continuous discharge, each discharge
build up to a constant pulse. These pulse are
counted by scaling circuits without intermediate
amplification.

35. • Paralysis are dead time of the Geiger muller tube
after each avalanche, the anode is surrounded by
excess number of cations which reduces the
potential gradient until the cations are moved to
certain distance from anode , no pulse will be
produced and GM tube is insensitive to radiation.
• This period is known as dead time and it is
followed by recovery time in which very small
pulses are produced. The dead time and recovery
time are together called as paralytic time.

37. • It is used to convert radiation energy into light
when an ionising particle is absorbed by any
one of the transparent scintillatiors, the
energy is emitted as a pulse of visible light or
near UV radiation. The light is absorbed by
photo multiplier tube. The combination of this
two are called as scintillation counter. It
consists of a phosphor , a photo multiplier
tube, high voltage supply and an amplifier.

39. • alpha counting- Silver activated
zinc sulphate
• beta counting - organic phosphor
like naphthalene of anthracene.
• gamma counting - Thallium
activated sodium iodide crystals.

40. • Advantage
• It does not have paralysis time. It is efficient
gamma detector than GM counter.
• Disadvntage
• It needs well stabilized high voltage supply.

41. • Great care should be taken to protect the
person who is handling it from the
harmful radiation.
• It must be stored in area not frequently
used by the people.
• Shielding may be done by using thick
glass, perspex or lead.

42. • Storage area must be checked for radioactivity
regularly.
• The working area should not be contaminated
with radioactive substances.
• Trays with absorbent tissue paper are used for
handling radioactive liquids, so that any
spillage will get absorbed by paper.

43. • Rubber gloves are used when working
with liquid radio pharmaceuticals.
• Mouth operated pipettes should not be
used.
• Smoking, eating and drinking should not
be done in the lab.
• Disposal must be carried out with care.

44. • Therapeutic use
• Diagnostic
• Sterilization
• Radiocarbon dating

45. Therapeutic use
• It is used for diseased conditions of
extensive cellular metabolic
malfunctions.
• It depends upon their ability to ionize
atoms.
• The Ionization energy is expressed in
terms of Meq.

46. SNO
DESCRIPTION RADIOACTIVE
ISOTOPE USES
AMMONIUM BROMIDE
CALCIUM CHLORIDE
Chromium EDTA
Colloidal gold
Chromium chloride
Human serum albumin
Potassium chloride
Triolen
82Br
45Ca
51Cr
198Au
51Cr
125I
24Na
125I
STUDY OF EXTRACELLULAR
MEASUREMENT
Study of ca metabolism
Determination of glomerular filtration
rate
Treatment of neo-plastic conditions and
general investigation of
reticuloendothelial cells
Studies of GIT protein loss in vivo
labelling and absorption studies
Study of cardiac cavity imaging scanning
of sub-arachnoid spaces detection of
brain tumours
Determination of exchangeable
poassium
Fat absorption studies

47. • Chromium 151 determine the RBC mass,
volume and scanning of spleen.
• Radio chromate serum albumin Cr 51 is used
to localize position, size of placenta with less
radiation exposure.
• Cobalt 57 or 60 is used to diagnose pernicious
anemia.

48. • Ferrous citrate Fe – 59 is used to
diagnose the Iron metabolism and RBC
formation.
• Radioactive gold Au 198 is used in
diagnosing the liver function.
• Iodine 131 is used to check thyroid gland
function, to determine the size, position
and possible tumor location.

49. • Sodium iodo hippurate I 131 used to check
Renal function.
• Sodium rose bengue I 131 is used to
determine the liver function.
• Chlormerodrin Hg 197 – radioactive tracer for
making scintillation scan of brain or kidney for
cysts, tumors and other abnormal.

50. • Technetium 99 M TC determining the
presence and location of tumors and lesions in
brain , liver, spleen and bone marrow, human
serum albumin- lung scan.
• Yetterbrium 109 – GFR in kidney
• Diatrizoate- Cerebral angiography
• Thermolabile substance are sterilized by radio
isotopes.