Radioactive medicine

The word radiation immediately conjures up images of disasters involving nuclear reactors or weapons. But radiation can also save lives. Medical researchers are busy developing new nuclear cures, a recent symposium at the Interfacultair Reactor Instituut (IRI) revealed.

Gamma rays can eliminate tumors, but they also often adversely effect a cancer patient’s healthy cells. Radiation treatments must be more selective. Last week, the IRI, which is linked to the TU, held a symposium about radiation and health. For the past three years, one of the institute’s focal points has been medical applications of radiation. The procedure for radiation treatments seems simple. Firstly, doctors inject special molecules with radioactive properties into the blood, which then spread throughout the body. The trick, however, is to ensure the molecules only cling to tumorous cells. Researchers strive to create ‘hangouts’ for nuclear medicine. The isotopes decay, thus arousing the internal radiation rays that then attack cells close to the tumor.

Cling

The medicine’s selectivity means it only clings to tumorous cells, not healthy cells, which is the measure of the technique’s success. Prof. Dr. E Krenning, of Erasmus University, experimented with radioactive peptide%hormones that

kill cancer cells in the intestines, adrenal gland and pancreas. To kill tumorous cells, Kreening used internal radiation with high-energy electrodes. The range of these destructive elements is a couple centimeters, which is enough to devastatingly strike the tumors.

To date, fifty people have received this treatment. Krenning stresses, however, that this new treatment’s development is a slow process. ”The precise dosage is unknown, as is how often the process must be repeated. But, in many cases, the quality of life was greatly improved.” The type of radiation is important, as is the life span of the radioactivity. The timing must be right: too long, means possible negative effects for people and the environment; and too short, means the radioactivity is lost during transport to hospital.

DNA-strands

The so-called Boron Neutron Capture Therapy (BNCT)is an example of modern nuclear medical science. Boron (an element) and separate neutrons don’t do much in our bodies. But when working together, they have a devastating effect. If, en route through the body, the Boron and neutrons come in contact with DNA, the cell is destroyed. The alpha particles break the DNA-strands in pieces and the cell dies.

With BNCT, researchers try to pump as much Boron into tumorouscells as possible; then, they externally attack these tumorous cells with neutrons. In the Netherlands, Dr. B.J. Slotman, of Amsterdam VU-hospital, has experience with this method. He administered radiation treatments to brain tumor patients in the reactor of Energiecentrum Netherland (ECN). ECN then built a separate treatment room. Slotman, however, warns against having unrealistically high expectations. ”It doesn’t work well yet, although recently there have been developments that justify new research, such as better clusters, better molecules and better calculations.”

Researchers discovered that, above all else, neutrons need the right amount of energy. Neutrons with too low energy levels stop travelling in our bodies after one centimeter, which isn’t far enough to attack brain tumors. Neutrons with too high energy levels attack all cells they come across, including healthy cells. Boron or no Boron, it matters not.

The magic number is an energy level of around 10 kilo-volt. For Delft’s technical researchers, neutrons emerging from the reactor with this magical energy level are grist to their mill. As for the question of whether or not IRI will now set up treatment rooms, Dr. A Verkooijen, IRI’s director, answers emphatically: ”Delft’s contribution is our unique knowledge of radioactivity, and that’ll remain so in future. Research is our core business and we’ll never treat patients.”

Gamma rays can eliminate tumors, but they also often adversely effect a cancer patient’s healthy cells. Radiation treatments must be more selective. Last week, the IRI, which is linked to the TU, held a symposium about radiation and health. For the past three years, one of the institute’s focal points has been medical applications of radiation. The procedure for radiation treatments seems simple. Firstly, doctors inject special molecules with radioactive properties into the blood, which then spread throughout the body. The trick, however, is to ensure the molecules only cling to tumorous cells. Researchers strive to create ‘hangouts’ for nuclear medicine. The isotopes decay, thus arousing the internal radiation rays that then attack cells close to the tumor.



Cling



The medicine’s selectivity means it only clings to tumorous cells, not healthy cells, which is the measure of the technique’s success. Prof. Dr. E Krenning, of Erasmus University, experimented with radioactive peptide%hormones that



kill cancer cells in the intestines, adrenal gland and pancreas. To kill tumorous cells, Kreening used internal radiation with high-energy electrodes. The range of these destructive elements is a couple centimeters, which is enough to devastatingly strike the tumors.



To date, fifty people have received this treatment. Krenning stresses, however, that this new treatment’s development is a slow process. ”The precise dosage is unknown, as is how often the process must be repeated. But, in many cases, the quality of life was greatly improved.” The type of radiation is important, as is the life span of the radioactivity. The timing must be right: too long, means possible negative effects for people and the environment; and too short, means the radioactivity is lost during transport to hospital.



DNA-strands



The so-called Boron Neutron Capture Therapy (BNCT)is an example of modern nuclear medical science. Boron (an element) and separate neutrons don’t do much in our bodies. But when working together, they have a devastating effect. If, en route through the body, the Boron and neutrons come in contact with DNA, the cell is destroyed. The alpha particles break the DNA-strands in pieces and the cell dies.



With BNCT, researchers try to pump as much Boron into tumorouscells as possible; then, they externally attack these tumorous cells with neutrons. In the Netherlands, Dr. B.J. Slotman, of Amsterdam VU-hospital, has experience with this method. He administered radiation treatments to brain tumor patients in the reactor of Energiecentrum Netherland (ECN). ECN then built a separate treatment room. Slotman, however, warns against having unrealistically high expectations. ”It doesn’t work well yet, although recently there have been developments that justify new research, such as better clusters, better molecules and better calculations.”



Researchers discovered that, above all else, neutrons need the right amount of energy. Neutrons with too low energy levels stop travelling in our bodies after one centimeter, which isn’t far enough to attack brain tumors. Neutrons with too high energy levels attack all cells they come across, including healthy cells. Boron or no Boron, it matters not.



The magic number is an energy level of around 10 kilo-volt. For Delft’s technical researchers, neutrons emerging from the reactor with this magical energy level are grist to their mill. As for the question of whether or not IRI will now set up treatment rooms, Dr. A Verkooijen, IRI’s director, answers emphatically: ”Delft’s contribution is our unique knowledge of radioactivity, and that’ll remain so in future. Research is our core business and we’ll never treat patients.”