Which one of the following elements’ isotopes is used in the treatment of cancer ?

Radioisotopes are widely utilized in medical oncology for both diagnosis and treatment. Cobalt-60 is a prominent isotope used in teletherapy (external beam radiation therapy) to treat various tumors by emitting high-energy gamma rays. While Iodine-131 is also used specifically for treating thyroid cancer [1][2], Cobalt-60 has historically been the standard for general cancer radiotherapy machines. Sodium isotopes are primarily used for diagnostic purposes, such as studying blood circulation, and Uranium is used as fuel in nuclear reactors rather than direct medical treatment [3]. In the context of general cancer treatment across various body parts, Cobalt-60 is the most characteristic answer. Modern medical research continues to develop new isotopes through PPP-mode research reactors to ensure affordable cancer care.

Sources

1. [1] https://www.sciencedirect.com/science/article/pii/S0936655522003144
2. [2] https://www.cdc.gov/radiation-emergencies/hcp/isotopes/iodine-131.html
3. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > Atomic explosion (Nuclear fatlout): > p. 83