[{"from": "human", "value": "What can you tell me about this molecule? [131Cs]"}, {"from": "gpt", "value": "The molecule is an unstable radioisotope of cesium (Cs) with radiocytotoxic application. Cs-131 is a gamma photon-emitting radionuclide with high energy and a relatively short half-life of 9.7 days. When used in prostate brachytherapy, Cs-131 demonstrated advantages over other commonly used isotopes."}]