(Radioactive Seed Implantation Therapy) Brachytherapy is a type of radiation therapy in which a sealed source (encapsulated radionuclide) is placed inside the patient as close as possible to the area being treated. The brachytherapy source delivers usually gamma or beta radiation at a distance up to a few centimeters either by surface, intracavitary or interstitial application.

See also Low Dose Rate, Cryotherapy, RF Thermal Ablation and Prostate Ultrasound.

Identification of an unknown radionuclide by measuring the decrease in radioactivity.

See also Decay.

The decay constant is inversely proportional to the radioactive half-life time. It is the fraction of a number of atoms of a radionuclide that disintegrates in a unit of time.

See also Half-Life, Decay.

An eluate is the solvent containing the decay product when a generator is eluted (gathering the daughter radionuclide from a generator using a suitable solvent).

See also Generator.

The process of removing, separating the daughter radionuclide from the generator is referred to as elution.

See Generator.