Mini Review - (2017) Volume 6, Issue 2

Radioisotopes and their Biomedical Applications

Nida Tabassum Khan*
Department of Biotechnology, Balochistan University of Information Technology, Quetta, Pakistan
*Corresponding Author: Nida Tabassum Khan, Department of Biotechnology, Balochistan University of Information Technology, Engineering and Management Sciences, Quetta, Pakistan, Tel: 03368164903 Email:


Radionuclides also termed as radioisotopes are elements that possess radioactivity. It means upon decay they emit radiations like alpha, beta or gamma particles and transformed their nuclei to a stable state. This decaying property of radioisotopes is called half-life. Thus radioisotopes could be used for numerous biomedical purposes such as cancer and tumour treatment, imaging, biochemical assays, biological labelling, sterilization, clinical diagnostics, radioactive dating etc.

Keywords: Urinalysis; Bioassay; Tracer; Carbon dating


Radioisotopes are widely used for a number of purposes following are some major applications of radioisotope.

Biochemical analysis

Biochemical assays are used to detect the presence and absence of radioisotopes. Therefore radioactive isotopes are used to label biological molecules. Such assays estimate the concentration of different constituents of plasma, body fluids, urine, blood etc. This technique is called radioimmuno-assays. An example is iodine bioassay which uses gamma emitters’ radionuclides of Iodine-125 and Iodine-131 that accrues inside thyroid. Therefore gamma detector can be used to quantify the iodine content (uptake and intake) of the person’s thyroid. The amount of measured radioiodine in the thyroid is compared with the Annual Limit on Intake (ALI) [1].


Radioisotopes are eliminated from the body in body fluids. By determining the active contents in urine one can analyse the uptake and intake of a specific radionuclide [1].

Tracer studies

Radioisotope is used for biological labelling of cells or entities for identification or tracing specific molecules in an organism. S 35 P 32 and I 125 are widely used radioisotopes used for labelling [2].

Carbon dating

Radioactive carbon-14 decay could be used to estimate the age of organic materials. For example carbon dating revealed that the burial cloth of Jesus Christ originated during the medieval times between A.D. 1260-1390. Similarly mummified remains found frozen in the Italian Alps were at least 5000 years old [3].

Potassium dating

Radio potassium-40 decays to stable 40Ar. Thus, by measuring relative ratio of 40K and 40Ar in rocks enable us to determine the age of rocks since its formation [4].

Clinical diagnostic

Positron Emission Tomography (PET) and PETCT make use of radionuclides emitting positron particle that is injected in to the target cell or tissue. Radionuclide decay release positron particles which interact with the nearby negatively charged particle resulting in the emission of gamma rays which is detected by a PET or gamma camera to give an exact image of the target [5].

Radionuclide Therapy (RNT)

This therapy makes use of radioisotopes that emits radiations upon their decay. These emitted radiations are used to target specific cancerous cells, tumours etc. to control their abnormal growth or completely eradicate it. For example cobalt-60 is use as a source of gamma radiation for radionuclide therapy, gamma knife radiosurgery and brachytherapy. Similarly targeted alpha therapy uses alpha-emitting radionuclide such as Bi-213, Lead-212, and Boron-10 to for treating pancreatic, ovarian and melanoma cancers [6].


Sterilization of surgical instruments such as syringes, gloves, clothing and instruments using gamma mitting radionuclides including Cobalt-60, Cs-137 etc. [7].


Incorporation of radioisotopes to biologically active substances is introduced into body in order to observe the functioning of an organ functioning or a metabolic path way etc. For example Yttrium-90 and Iodine-131 is used as radiopharmaceuticals for the treatment of non-Hodgkin’s lymphoma and hyperthyroidism respectively (Table 1) [8].

Isotope Half-life Medical uses
Ac-225 10.0d Cancer treatment
Ac-227 21.8y Cancer treatment
Am-241 432y Detection of osteoporosis
As-72 26.0h PET/ SPECT
As-74 17.8d In biomedical
At-211 7.21h Cancer treatment
Au-198 2.69d Cancer treatment
B-11 Stable Tumor treatment
Be-7 53.2d Used in berylliosis (chronic lung disease) studies
Bi-212 1.10h Cancer treatment, cellular dosimetry studies
Bi-213 45.6m Cancer treatment
Br-75 98m SPECT/ PET
Br-77 57h Monoclonal antibody labeling
C-11 20.3m Radiotracer in PET scans
C-14 5730y Radiolabeling for tumors detection
Cd-109 462d Cancer detection, pediatric imaging
Ce-139 138d Calibration of germanium gamma detectors
Ce-141 32.5d diagnosis of gastrointestinal tract,  myocardial blood flow  measurement
Cf-252 2.64y Cancer treatment.
Co-55 17.5h Planar  and SPECT /PET imaging
Co-57 272d In radiotracer, source for X-ray fluorescence spectroscopy
Co-60 5.27y Teletherapy, disinfectant, radiotherapy
Cr-51 27.7d Radiolabeling and dosimetry
Cs-130 29.2m Myocardial localizing agent
Cs-131 9.69d Intracavity implants for radiotherapy
Cs-137 30.2y Blood irradiators, PET imaging, and tumor treatment
Cu-61 3.35h Planar imaging, SPECT or PET
    Positron emitting radionuclide
Cu-62 4.7m Tracer, PET/SPETC imaging
Cu-64 12.7h Cancer treatment
Cu-67 61.9h Cancer treatment/diagnostics, radio immunotherapy, SPECT or PET
Dy-165 2.33h Radiation synovectomy, rheumatoid arthritis treatment
Eu-152 13.4y Medical uses
Eu-155 4.73y Osteoporosis detection
F-18 110m Radiotracer, imaging
Fe-55 2.73y Heat source
Fe-59 44.5d Medical use
Ga-64 2.63m Treatment of pulmonary diseases ending in fibrosis of lungs. detection of Hodgkin’s/non-Hodgkins lymphoma
Ga-67 78.3h osteomyelitis detection
Ga-68 68.1m Imaging, detection, treatment of pancreatic cancer
Gd-153 242d Photon source, detection, imaging
Ge-68 271d Imaging
H-3 12.3y Radiolabeling, imaging
I-122 3.6m Neurology studies
I-123 13.1h Imaging, cancer treatment
I-124 4.17d Tracer, imaging
    Detection of osteoporosis,
imaging, tracer, brain
cancer treatment,
radiolabeling, interstitial
radiation therapy
I-125 59.9d
I-131 8.04d Tumor treatment, antibody labeling, radio immunotherapy, cellular dosimetry, SPECT imaging, treatment of prostate cancer
I-132 2.28h Mapping of areas
In-111 2.81d Detection of transplant rejection, imaging, labeling, treatment of tumors
In-115m 4.49h Radiolabelling
Ir-191m 6s Cardiovascular angiography
Ir-192 73.8d treatment of cancers
Kr-81m 13.3s Lung imaging
Lu-177 6.68d Heart disease treatment), cancer therapy
Mn-51 46.2m Myocardial localizing agent
Mn-52 5.59d PET scanning
Mo-99 65.9h Organ imaging
N-13 9.97m PET imaging, myocardial perfusion
Nb-95 35d Myocardial tracer, PET imaging
O-15 122s PET imaging / SPECT imaging
Os-191 15.4d Cardiovascular angiography
Os-194 6.00y Cancer treatment
P-32 14.3d Cancer treatment, imaging, radiolabeling
P-33 25d Labeling
Pb-203 2.16d Planar imaging, SPECT or PET, cellular dosimetry
Pb-212 10.6h Radioactive labelling, cellular dosimetry
Pd-103 17d Prostate cancer treatment
Pd-109 13.4h Potential radio therapeutic agent
Pu-238 2.3y Pacemaker
Ra-223 11.4d Cancer treatment
Ra-226 1.60e3y Target isotope to make Ac-227, Th-228, Th-229
Rb-82 1.27m Myocardial imaging agent, PET imaging, blood flow tracers
Re-186 3.9d -
Re-188 17h Cancer treatment
Rh-105 35.4h Potential therapeutic applications, radiolabeling
Ru-97 2.89d Monoclonal antibodies labelling, imaging
Ru-103 39d Radiolabeling, imaging
S-35 87.2d Radiolabeling, cellular dosimetry
Sc-46 84d Imaging
Sc-47 3.34d Treatment of cancer/diagnostics
Radio immunotherapy
Se-72 8.4d Brain imaging, immunotherapy
Se-75 120d Radiotracer
Si-28 Stable Radiation therapy of cancer
Sm-145 340d Brain cancer treatment
Sm-153 2.00d Cancer treatment/diagnostics
Sn-117m 13.6d Pain relief
Sr-85 65.0d Detection and imaging
Sr-89 50d Cancer treatment, cellular dosimetry
Sr-90 29.1y Immunotherapy
Ta-178 9.3m Imaging
Ta-179 1.8y Source of X-ray
Ta-182 115d Urinary cancer treatment
Tb-149 4.13h Cancer treatment
Tc-96 4.3d Animal studies
Tc-99m 6.01h nuclear imaging
Th-228 720d Cancer treatment
Th-229 7300y cancer treatment
Tl-201 73.1h Imaging, cellular dosimetry
Tm-170 129d Treatment of cancers
Tm-171 1.9y Medical uses
W-188 69.4d Treatment of tumors
Xe-127 36.4d Neuroimaging
Lung studies
Xe-133 5.25d Lesion detection
Y-88 107d Cancer tumor therapy
Y-90 64h cellular dosimetry, treating rheumatoid arthritis and cancers
Y-91 58.5d Tumor treatment, dosimetry
Yb-169 32d Clinical diagnostics
Zn-62 9.22h Study of neurology
Zn-65 244d Medical  uses
Zr-95 64.0d Medical uses

Table 1: Lists of radionuclides and their biomedical applications [9-48].


Radioisotopes are used for numerous medical purposes which marks it potential in the field of medical science.


Citation: Khan NT (2017) Radioisotopes and Their Biomedical Applications. J Biomol Res Ther 6: 156.

Copyright: © 2017 Khan NT. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.