An unstable nucleus is radioactive, which means that it spontaneously emits small particles of energy called radiation to become more stable.
Radioisotope: An isotope of an element that emits radiation.
Atomic Symbols: Written with the mass number in the upper left corner and the atomic number in the lower left corner.
Mass Number: The sum of the numbers of protons and neutrons in the nucleus.
Atomic Number: It is equal to the number of protons.
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Isotope | Half-Life | Radiation | Medical Application |
---|---|---|---|
Au-198 | 2.7 days | Beta | Liver imaging; treatment of abdominal carcinoma |
Ce-141 | 32.5 days | Beta | Gastrointestinal tract diagnosis; measuring blood flow to the heart |
Cs-131 | 9.7 days | Gamma P | Prostate brachytherapy |
F-18 | 110 min | Positron | Positron emission tomography (PET) |
Ga-67 | 78 h | Gamma | Abdominal imaging; tumor detection |
Ga-68 | 68 min | Gamma | Detection of pancreatic cancer |
I-123 | 13.2 h | Gamma | Treatment of thyroid, brain, and prostate cancer |
I-131 | 8.0 days | Beta | Treatment of Graves’ disease, goiter, hyperthyroidism, thyroid and prostate cancer |
Ir-192 | 74 days | Gamma | Treatment of breast and prostate cancer |
P-32 | 14.3 days | Beta | Treatment of leukemia, excess red blood cells, pancreatic cancer |
Pd-103 | 17 days | Gamma | Prostate brachytherapy |
Sr-85 | 65 days | Gamma | Detection of bone lesions; brain scans |
Tc-99m | 6.0 h | Gamma | Imaging of skeleton and heart muscle, brain, liver, heart, lungs, bone, spleen, kidney, and thyroid; most widely used radioisotope in nuclear medicine |
Y-90 | 2.7 days | Beta | Treatment of liver cancer |
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