This document discusses radiopharmaceuticals, which are radioactive substances or drugs used for diagnostic or therapeutic medical procedures. It describes the different types of radiation emitted (alpha, beta, gamma) and their penetrating abilities. Various nuclear isotopes are discussed as well as techniques for measuring radioactivity levels. Applications of radiopharmaceuticals are outlined, including uses in clinical settings like cancer treatment, diagnosis of medical conditions, and research. Precautions are mentioned regarding allergies, pregnancy, breastfeeding, and use in children to minimize radiation exposure risks. Proper dosage is also highlighted as important to derive safe and effective treatment levels.

1. RADIO PHARMACEUTICALS
Kencha swathi
Assistant professor
ABIPER
BANGALORE

2. INTRODUCTION
 Radiopharmaceuticals are the radioactive
substances or radioactive drugs for diagnostic or
therapeutic interventions.
 A radioactive isotope can be injected safely into
the body and a carrier molecule which delivers
the isotope to the area to be treated.
 Alpha rays(α-rays):These rays or particles have
the least penetrating power , positive charge and
have a strong imagistic field.

3.  Beta rays ( β- rays): They have greater
penetrating power than that of alpha rays.
 β- rays are of two types –
(i)Electrically positive particles (positrons)
(ii)Electrically negative particles( negatrons)
 Gamma rays(γ-rays): These have praoduced
during nuclear fission. More penetrating than
alpha & beta rays.

4. ISOTOPES
 Nuclides having the same number of protons but
different number of neutrons are termed as
isotopes.
 Radioisotopes have been those that undergo
nuclear changes or rearrangements that cause the
emission of radiation.

6. MEASUREMENT OF RADIO ACTIVITY
 To measure the radiations of alpha,beta and
gamma particles, many techniques involving
detection and ounting of individual particles as
photons are available.
 The method selected for the measurement of
radioactivity depends upon the extent of energy
dissipation and penetrability of radiation.

7. The Techniques are :
1.Ionisation chambers
2.Proportional counters
3. Geiger-Muller counters
4.Scintillation method especially for
counting gamma radiations.
5.Autoradiography
6. Solid state detectors

9. APPLICATIONS

10. CLINICAL APPLICATIONS
Radioisotopes are used in Therapeutics:
 Gold (¹⁹⁸Au ) is used in the treatment of abdominal
effusion associated with malignant tumour,Carcinoma of
uterus and urinary bladder.
 Sodium phosphate (³²P) is used to treat polycythemia
(decrease the rate of formation of RBC) & leukemia.
 Cobalt labelled cyanocobalamins(Co-57,C0-58,Co-60)
used in the diagnosis of pernicious anaemia.
 Sodium iodide (¹³¹I) used in the treatment of thyroid
disorders.

11. Radioisotopes in Diagnosis:
 Ferric citrate(⁵⁹Fe) injetion is used for the
diagnosis of haematological disorders.
 Sodium iodohippurate I-131 injection is used for
the diagnosis of renal functions.
 Iodine( ¹³¹I) serum albumin injection used to
identify the cardiovascular functions.

12.  Radioisotopes are used in research.
 Sterilization: Radiopharmaceuticals are used for
sterilizing final packed containers and surgical
instruments in hospitals.
 Radioactive calcium(Ca-44 & Ca-45) are used to
study bone structure and for the treatment of
carcinoma of bone.
 Cobalt-60 is used for the sterilisation of surgical
materials and dressings by the gamma radiations.
 Radioactive isotopes of cyanacobalamin used to
study the absorption and deposition of vitamin B₁₂
in normal individuals.
 Gold( Au-198) solution is used in estimation of
reticuloendothelial activity

13.  Hydrogen(H-2 & H-3) are useful to determine
total body water.
 Iron(Fe-59) used to measure RBC life span
and iron metabolism
 Radioactive chromium-Sodium chromate( Cr-
51) is used to study red cell volume and
survival time.
 Iodine(¹³¹I) is used in the treatment of
hyperthyroidism and hypothyroidism.
 ¹³¹I is used in the destruction of thyroid
follicles due to β-particles and surgical
removal of thyroid gland.

15. DOSAGE OF RADIOPHARMACEUTICALS
 Proper dosages are derived through careful study of
pharmacokinetics,physical characteristics of
radionuclide,metabolism of subject,pharmacodynamics of the
radiopharmaceutical of the subject.
 The chemical and radiotoxicities and adverse reactions are well
understood before an optimal and safe dosage is recommended.
 Doses are typically scaled by weight, or total body surface area,
and reduced for children.
 The recommended dosage for a specific indication and route of
administration are stated by the drug manufacturers in the package
insert, and are readily available online.

16. DOSAGE

18. HAZARDS
 Allergies
 Pregnancy – Radiopharmaceuticals are not
recommended for use during pregnancy to avoid
exposure of foetus to radiation.
 Thyroid damage – Radioactive iodine enters into
the baby’s thyroid gland during pregnancy in high
amounts and causes thyroid damage.
 Breast feeding – Radiopharmaceuticals pass into
the breast milk and expose the baby to radiation.
 Children – Low amount of radiopharmaceuticals
are used in children and diagnosed safely.

19. PRECAUTIONS

20. THANK YOU