A Review: Radioisotopes used in Cancer Therapy

Abstract

The critical role that radioisotopes play in modern healthcare is examined in this review. In contemporary medicine, radioisotope atoms with unstable nuclei that release ionizing radiation have become indispensable instruments. Their special qualities make it possible to identify and treat a variety of illnesses, transforming medical care and enhancing patient outcomes. The most widely used radioisotopes, their properties, and their various uses in the diagnosis and treatment of various medical conditions are examined in this review. Special attention is paid to diagnostic methods like positron emission tomography (PET) and single-photon emission computed tomography (SPECT), which have since transformed imaging by making it possible to see an anatomical structures and metabolic processes in great detail. This study highlights the significance of medical radioisotopes in nuclear medicine in relation to cancer diagnosis and treatment. Additionally, potential medical radioisotope production techniques are asses sed, and by contrasting with experimental data from the literature, a method for producing two medical radioisotopes via neutron and deuteron-induced reaction processes is examined.

Introduction

Radiopharmaceuticals are radioactive substances used for diagnosing and treating various diseases, especially cancer. These substances consist of radioisotopes—unstable atoms that emit radiation as they decay into stable forms. Their ability to target specific tissues makes them powerful tools in medical imaging, cancer therapy, and biological research.

???? Historical and Medical Significance

• First use: Iodine-131 in 1938 for thyroid function assessment.

• Modern imaging techniques like PET and SPECT rely on radioisotopes to visualize organ function and metabolism.

• Radioisotopes offer greater precision than traditional imaging due to their ability to bind to specific cells or tissues.

???? Medical Applications of Radioisotopes

Diagnostic Use:

• Technetium-99m: Most widely used; scans bones, heart, and organs.

• Chromium-51: Tags red blood cells.

• Copper-64, Iodine-125, and others help detect specific disorders or functions.

Therapeutic Use:

• Targeted radionuclide therapy delivers radiation directly to cancer cells, minimizing harm to healthy tissues.

• Used for treating thyroid, lymphoma, prostate cancers, and bone metastases.

• Lutathera (liquid radiation) is an example of targeted therapy infused with kidney-protective agents.

???? How Radioisotope Therapy Works

• Functions similarly to chemotherapy (circulates in blood) but binds selectively to cancer cells.

• Can be administered orally, intravenously, or interstitially.

• Provides whole-body treatment, unlike external radiation that targets specific areas.

? Advantages of Radioisotope Therapy

1. High precision: Targets only cancerous cells.

2. Effective destruction of cancer cells through DNA damage.

3. Minimally invasive: Often involves oral or IV delivery.

4. Suitable for metastatic cancer.

5. Preserves organs by avoiding surgical removal.

6. Combines well with other therapies.

7. Shorter treatment duration in some cases.

8. Theranostics: Dual function in diagnosis and therapy (e.g., Iodine-131, Lutetium-177).

?? Disadvantages of Radioisotope Imaging & Therapy

1. Radiation exposure: Minimal per scan but cumulative over time.

2. High cost: Specialized equipment and tracers are expensive.

3. Short half-lives of tracers (e.g., F-18: 110 mins) complicate logistics.

4. Possible allergic reactions (rare).

5. Limited anatomical detail: Needs combination with CT/MRI.

6. Access issues in low-resource settings.

???? Commonly Used Radioisotopes in Diagnostics

?? Radioactive Decay and Protection

• Decay: Spontaneous release of radiation to become stable.

• Types of radiation: Alpha, beta, and gamma.

• Protection Measures:

  • Maximize distance from source.

  • Use lead shielding (bricks, aprons).

  • Minimize exposure time.

  • Use remote handling tools.

Background Radiation Sources:

• Internal (20%), Terrestrial (30%), Cosmic (50%)

• Higher altitudes = higher exposure (e.g., Gangtok, Sikkim).

???? Historical Context

• Henri Becquerel (1896): Discovered natural radioactivity.

• Marie & Pierre Curie (1898): Isolated polonium and radium.

• Today, about 200 radioisotopes are commonly used in medicine.

• Most are artificially produced in nuclear reactors or cyclotrons.

Conclusion

In conclusion, this article explains how radiopharmaceuticals can also be used to diagnose specific cancers because, once the drugs are administered, oncologists can monitor radioactivity throughout the body to detect the presence of cancer. Special imaging systems used for diagnostic purposes include gamma cameras and similar devices.

References

[1] Fassbender ME. Guest Edited Collection: Radioisotopes and radiochemistry in health science. Scientific Reports 2020 10:1 [Internet]. 2020 Jan 10 [cited 2024 May 25];10(1):1–3. Available from: https://www.nature.com/articles/s41598-019-56278-1 [2] Wadas TJ, Pandya DN, Solingapuram Sai KK et al.; Molecular targeted a-particle therapy for oncologic applications. AJR Am J Roentgenol, 2014; 203(2): 253–260. [3] Baidoo KE, Yong K, Brechbiel MW et al. Molecular pathways: targeted a-particle radiation therapy. Clin Cancer Res., 2013; 19(3): 530–537. [4] De Lima JJP. Radioisotopes in medicine. Eur J Phys [Internet]. 1998 Nov 1 [cited 2024 May 24];19(6):485. Available from: https://iopscience.iop.org/article/10.1088/0143-0807/19/6/003 [5] Zalutsky MR et al. Radioimmunotherapy with particle emitting radio- nuclides. Q J Nucl Med Mol Imaging, 2004; 48: 289–296. [6] World Nuclear Association, 2011, [26.01.2011], available from: http://www.world-nuclear.org/info/inf55.html. [7] A. Stanciu, M. Contineanu and M. Stanciu, “Actiunea radiatiilor ionizante asupra sistemelor biologice”, Electra, Bucharest, 2004, p. 52-136. [8] Özgenç E, Gundogdu E, Akgun E, Ozgenc E. Pharmacological uses of Radiopharmaceuticals: An Overview of Radiopharmaceuticals Used in Treatment. J Pharm Sci [Internet]. 2021 [cited 2024 May 24];46:93–104. Available from: https://www.researchgate.net/publication/355476596 [9] Radioisotopes and Their Biomedical Applications | Enhanced Reader. [10] 10.Gupta S, Batra S, Jain M et al. Antibody labelling with radio-iodine and other radiometals. Methods Mol Biol., 2014; 1141: 147–157 [11] Dale, R. & Carabe-Fernandez, A. The study of radiobiology in standard radiotherapy. Cancer Biother. Radiopharm. 20, 47–51 (2005). [12] Davies AJ: Radioimmunotherapy for B cell lymphoma: 90Y-ibritumomab tiuxetan and 131I-tositumomab. Oncogene, 2007; 26. [13] Sahoo S. Production and Applications of Radioisotopes Physics Education 2006; 3:1-11. [14] 5. Becquerel H. Emission des radiations Nouvelles par l’uranium metallique. C R Acad Sci Paris. 1896; 122:1086. [15] Fowler, J. F. Radiobiological aspects of low-dose rates in radioimmunotherapy. Int. J. Radiat. Oncol. Biol. Phys. 18, 1261–1269 (1990). Radiobiological treatment of RPT. [16] Carter PJ: Potent antibody therapeutics by design. Nat Rev Immunol, 2006; 6: 343-357. [17] Mundigl S. Modernisation and consolidation of the European radiation protection legislation: the new Euratom Basic Safety Standards Directive. Radiat Prot Dosimetry [Internet]. 2015 Apr 1 [cited 2024 May 25];164(1–2):9–12. Available from: https://dx.doi.org/10.1093/rpd/ncu285 [18] Roy RR and Nigam BP. Nuclear Physics Theory and Experiment. Sons, John Wiley, Inc. Manchanda VK, Technical Talk on Radiation Technology Applications and Indian Nuclear, New York (1967). Programme: Societal profit, in Aarohan 2K5 at NIT, Durgapur; Beiser A, Concepts of Modern Physics, McGraw-Hill Book Company, Singapore (1987). [19] Packard AB, Kronauge JF, Brechbiel MW. Metalloradiopharmaceuticals. In: Clarke, M.J.,Sadler, P.J., eds. A Metalloradiopharmaceuticals II, Diagnosis and Therapy Eds. NY:Spriner-Verlag, 1999:45-116. [20] Milenic DE, Garmestani K, Chapell LL, Dadachova E, Yordanov A, Ma D, et al. In vivocomparison of macrocyclic and acyclic ligands for radiolabeling of monoclonal antibodieswith 177Lu for radioimmunotherapeutic applications. Nuc Med Biol 2002; 29:431-42. [21] Wang X, Xiao J, Jiang G. RETRACTED: Nursing analysis based on embedded system for real-time monitoring of medical data and iodine 131 treatment of thyroid cancer. Microprocess Microsyst. 2021 Mar 1;81:103660. [22] S.J. Aldestein and F.J. Manning, “Isotopes for Medicine and the Life Sciences”, National Academy Press, Washington D.C., 1995, p. 16-45. [23] M.W. Mortensen, O. Bjorkdahl, P.G. Sorensen, T. Hansen, M.R. Jensen, H. Gundersen and T. Bjornholm, Bioconjug. Chem., 2006, 17, 284-290. [24] E.H. Elowitz, R.M. Bergland, J.A. Coderre, D.D. Joel, M. Chadha and A.D. Chanana, Neurosurg., 1998, 42, 463-469. [25] Varia MA, Stehman FB, Bundy BN, Benda JA, Clarke-Pearson DL, Alvarez RD, et al. A randomized trial conducted by the Gynecologic Oncology Group compared intraperitoneal radioactive phosphorus (32P) with observation following a negative second-look laparotomy for stage III ovarian carcinoma. J Clin Oncol., 2003; 21: 2849–55. doi: 10.1200/JCO.2003.11.018.

Copyright

Copyright © 2025 Linge Archana Dipak, Shinde Akanksha Prakash. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.