Healthcare providers sometimes treat cancer patients with radioactive cesium (cesium-137). Cesium is an element. Caesium compounds with chlorides are used in photoelectric cells. Cesium can be utilized during oil drilling to help maintain pressure. Much cesium demand also comes from the oil and gas industry, which uses cesium formate brines in drilling fluids to prevent blow-outs in high-temperature, over-pressurized wells. The following points highlight the applications or uses of the Cesium: Cesium formate-based drilling liquids are widely utilized in the extractive oil industry. Caesium is widely used in the production of electricity, electronics and in chemistry. Caesium nitrate is used to make optical glasses. Despite serious safety concerns, non-radioactive cesium is taken by mouth for treating cancer.This is sometimes called “high pH therapy.” It is utilized in thermionic generators, which convert heat energy into electrical energy. In its natural state, cesium is not radioactive.However, it can be made radioactive in the laboratory.People use both forms of cesium for medicine. Cesium Uses. Its most common application is in the oil industry. Today, cesium is still not widely used. Uses of Cesium Today. Caesium is also used in the manufacturing of infrared lamps. Non-radioactive cesium is also used to treat depression. Caesium is widely used in clocks. Caesium is used in industries as a catalyst promoter. In industry, radioactive cesium is also used in instruments that measure thickness, moisture, and liquid flow.