Novel radiopharmaceutical materials for medical applications
Radiopharmaceuticals are used extensively as diagnostic and therapeutic agents in nuclear medicine. These medicinal products contain a radioisotope in their molecule structure. The molecule conveys the radioisotope to specific organs, tissues or cells whilst the radioisotope is selected for its radioactive properties.
Radioisotopes emitting penetrating gamma rays or positrons are used for diagnostic imaging where the radiation has to escape the body before being detected by a specific device (SPECT/PET scanner). Typically, the radiation emitted by an isotope used for imaging vanishes completely after 1 day through radioactive decay and normal body excretion. The most common isotopes for imaging include 99mTc, 123I, 131I-131, 18F and 68Ga. Meanwhile, radioisotopes emitting short range particles (alpha or beta) are used for therapy due to their power to lose all their energy over a very short distance, thereby causing a lot of local damage (such as cell destruction). This property is used for therapeutic purposes: cancer cells destruction, pain treatment in palliative care for bone cancer or arthritis. Such isotopes usually stay longer in the body than imaging ones; this is intentional in order to increase treatment efficiency, but still remains limited to several days. The most common therapeutic isotopes include 131I, 89Sr, 90Y, 153Sm and 177Lu.