how to illuminate the interior of our body with particle accelerators

The historical motivation of large particle accelerators, created in the 20th century, was originally aimed at the field of basic science, but today their applications have expanded to improve the daily lives of mankind. These include various aspects such as food preservation, water purification, semiconductor production, biomolecule development, construction of new polymeric materials և primarily medicine and pharmacology.

Atomic medicine uses atoms of the same element whose nuclei have different numbers of neutrons, called isotopes or radioisotopes, if they also emit certain particles.

These radioisotopes have been produced in recent decades for a variety of medical uses, such as therapy and computer imaging. The most common computer imaging technique using radioisotopes is called SPECT (Computed tomography of single photon emissions), In the technetium-99m (99mTc) isotope, which emits photons (gamma rays).

This medicine mainly consists of a micro-lamp that illuminates the human body. The SPECT scanner, using a camera that is sensitive to these photons, rotates around the patient ամբողջական photographs complete images that the computer classifies into sections. 99mTc has been produced in nuclear reactors for decades using molybdenum-99 degradation, and in the last decade with proton accelerators proposed by the International Atomic Energy Agency (IAEA).

In practice, one of the most useful methods of visualizing medical diagnosis is called PET (Positron emission tomography): Although PET is still less used than the previous SPECT, in part because of its relatively high cost, it has been improved և its use is much wider in medicine, given that the resulting image provides a much better solution. : That is why in recent years his interest in various specialties of nuclear medicine has expanded.

Therefore, the imaging of new PET using various radiopharmaceuticals is a field of research that has extraordinary significance for current biomedicine.

PET radiopharmaceuticals

Various short positron emitters are essential for medical diagnosis using PET. Some of the radioisotopes that can be produced by low-energy accelerators are Fluorine 18, Oxygen 15, Nitrogen 13 և Carbon 11 (18F, 15O, 13N և 11C, respectively).

Because positrons are the antimatter of electrons, these radiopharmaceuticals emit positrons that collide with electrons in a patient’s body to produce photons that create an image. This is processed by a computer so that medical staff can see and diagnose.

These drugs behave like themselves nanolines which allow high-resolution images to diagnose multiple pathologies.

Logistical challenge

Fluoride 18 is one of the most widely used isotopes in many hospitals. It can be produced externally, as it has a short but long half (about 110 minutes) to be sent to a medical center from abroad.

However, external shipping requires the production of many more batches of high levels of radioactivity, as some of them decompose and become inactive during transport hours. Consequently, the current external production of radiopharmaceuticals globally requires surpluses in terms of economic, energy, radioactivity and speed. The effectiveness of these problems can be improved through the local production of hospital-adapted pharmaceutical doses.

Oxygen, nitrogen, and carbon are very important elements because they make up the cells of the human body and can be used to label a wide range of medicinal compounds.

However, the short half-life of its isotopes (two to twenty minutes) requires local production in the hospital. This implies the impossibility of its medical use until it is produced immediately without the need for transport.

There is a great deal of interest in these other PET radiopharmaceuticals, which are still rarely used in medicine. In particular, the great interest in 11C is very remarkable, which can replace the normal 12C in any molecule of the human body.

In this case of Carbon 11 radioisotope, we can imagine that the nano-lamp that illuminates the PET images uses its battery in a few minutes և disappears after operation without being removed.

Therefore, the local production of all types of PET radiopharmaceuticals is a potential application for biomedicine. The localized production of these promising isotopes using compact accelerators will allow their actual medical use.

Accelerators for radiopharmaceutical production

The most common form of radiopharmaceutical production is nuclear reactors or particle accelerators. The most common way today is to use cyclotrons, which have been used for decades.

These devices are heavy-duty, often accelerating protons to tens of MeV (megae electron volts) in medical applications. Its costs of production, operation, maintenance, energy are high, they do not allow hospitals to generalize its use.

Linear accelerators (LINear Accelerator (LINAC)), especially the new compact generation, have several advantages over traditional cyclotrons.

First of all, Linacs have less radiation losses than cyclotrons, because the latter, due to their circular nature, are constantly subject to the centrifugal force Lorentz, which touches photons, and the ray loses energy.

Second, the new generation Linacs are much more compact, economical, lighter, with lower requirements for energy costs and radioactive protection.

Thanks to these many benefits, this type of accelerator is a great alternative to producing low-proton low-energy radiotherapy in the hospital.

Linac 7 project

Linac 7 is a project consisting of a new generation of proton linear accelerator, fully developed, designed and built by the UPV / EHU Particle Radiation Laboratory (IZPILab-Beam Laboratory) of the University of the Basque Country, many of the components of which are currently in operation. .

One of the most important healthcare applications developed under this program is the production of various types of drugs around major local clinical centers. Accelerator sizes and specifications can serve the hospital in-house laboratory or even allow it to be shipped in a small truck to be distributed to radiopharmaceutical production on-demand at many medical facilities that require it.

There is great interest in Europe in the use of different versions of particle accelerators for the production of medical radioisotopes. In particular, the European Commission promotes the ARIES consortium (Accelerated research և innovation for European science և society), the report of which was published on June 22, 2020, describes the current state of production of medical radioisotopes with accelerators և very specifically expresses the scientific, medical և industrial interest in the development of new Linacs for PET.

Leave a Reply

Your email address will not be published.