Secondary Auger electrons and prostate cancer therapy

Complete text of publication follows. Auger emitters emit electrons of relatively low energy, from ∼ 25 KeV to ∼ 500 eV, and therefore are of relatively low range. Thus, an important medical application for Auger emitters emerges as an effective means of controlling cancer due to the restrictive irradiation volume surrounding the emitter and therefore the possibility of a selective attack on cancer cells. There are two ways to perform an experiment with an Auger emitter. The first is to use a radionuclide that emits Auger electrons (Barchytherapy). The second is to stimulate a stable, potential Auger emitter inside the malignant cell using external irradiation. To achieve a therapeutic benefit, one must synthesize tumor selective chemicals. These compounds (porphyrins, phthalocaynines) should have two properties: i) Physically, it must have a metal ion with a large atomic number that will produce a large number of Auger electrons, ii) Chemically, it should be water-soluble and able to penetrate the cell membrane and attach itself to the cell target (e.g. DNA). The chemical properties sem contradictory, however, since these compounds are big molecules and have many side chains, one can build a porphyrin molecule that has on one side a hydrophilic component and on the other side a hydrophobic component. The physical and chemical aspects are discussed and some biological results will be presented