Radiation injury & mercury deposits in internal organs as a result of thallium-201 chloride intravenous injection for SPECT imaging; additional biochemical information obtained in the images of organs from SPECT or PET scans; & potential injury due to radiation exposure during long distance flights.

Abstract

In order to study functional as well as anatomical aspects of various internal organs, SPECT (Single Photon Emission Computerized Tomography) has been used extensively for evaluation of these organs. For SPECT study, intravenous injection of radioactive substances such as technetium-99m (20 millicuries) & thallium-201 chloride (3 millicuries) is commonly used. Although the physical half-life of thallium-201 chloride is 73 hours, its biological half-life is often more than 3.5 times that. Following intravenous injection of thallium-201 chloride it is concentrated in the heart, liver, kidneys, pancreas, thyroid gland, testes or ovaries, and then eventually decays to mercury. Because of its relatively long physical & biological half-lives, thallium-201 chloride may produce mild radiation injury while it remains radioactive. Similar injuries may be induced by technetium-99m (often used for brain SPECT), which radiates Gamma rays (140 KeV), but since its physical half-life is only 6 hours, the side effects are not as significant as those of thallium-201 chloride. Since the main component of thallium-201 chloride radiation is X-ray (68-82 KeV), which consists of photons with a very short wavelength and a high penetrating power, prolonged exposure can induce electromagnetic field-induced injury. As a previous study of the principal author on electromagnetic field exposure indicated, electromagnetic field-induced injury causes the change of L-amino acids to D-amino acids. 2 days after SPECT study of the heart with intravenous injection of thallium-201 chloride, the principal author experienced shortness of breath, loss of appetite, dizziness, fever, and general malaise within the week, and found a progressively significant increase in D-glutamic acid and decrease in L-glutamic acid peaking 2 weeks after the initial injection but lasting for many weeks after in organs such as the heart, liver, kidneys, pancreas, thyroid gland & testes, where radioactive substances had accumulated and radiation was at an average of about 400 counts/min. Even 2 months after the initial injection, the abnormal ratio of D-amino acids and L-amino acids had not returned to normal (in the radiation exposed heart, L-amino acids: 6 mg/dl with D-amino acids: 5 mg/dl; normal tissue, L-amino acids: 10 mg/dl with D-amino acids < 1 mg/dl). The principal author tried to find a safe method of reducing possible radiation injury and accelerating the elimination of the already deposited mercury.(ABSTRACT TRUNCATED AT 400 WORDS)