הפוסט Theragnostics הופיע לראשונה ב-ש.ר.י.

For therapeutic purposes (radiotherapy), nuclear medicine uses radiopharmaceuticals that emit alpha or beta radiation, allowing targeted eradication of the target cells (e.g., cancer cells) in a controlled manner, while minimizing damage to healthy tissues.

In summary, nuclear medicine is used for disease diagnosis and treatment, for patient management and monitoring treatment efficacy, and as a prognostic tool in a wide range of fields, including oncology, neurology, cardiovascular diseases, and more. It is an integral part of the diagnostic and therapeutic workup of many patients.

הפוסט Nuclear Medicine הופיע לראשונה ב-ש.ר.י.

A radiopharmaceutical is a molecule composed of two main components: one is radioactive, and the other has a biochemical nature, designed to direct the radiopharmaceutical toward a specific organ (the target organ). The radiopharmaceutical enables imaging of molecular targets, physiological and pathological processes, as well as targeted therapy of various conditions.  The relative specificity of the radiopharmaceutical for a given tissue, protein, or specific process allows for imaging or targeted therapy. The radioactive materials used generally have a relatively short half-life and are administered in an optimal dose that enables effective and safe imaging and/or therapy.

The use of radiopharmaceuticals in combination with appropriate imaging devices (cameras/ scanners) provides non-invasive information about the functional status of specific organs, the presence of molecular targets (“molecular imaging”), and various pathological processes.

הפוסט Radiopharmaceuticals הופיע לראשונה ב-ש.ר.י.

Ionizing radiation is radiation that causes ionization of atoms, meaning it releases electrons from atoms or molecules. Types of ionizing radiation include radioactive particle emissions such as alpha and beta radiation, as well as high-frequency electromagnetic radiation like UV radiation (UV-B and UV-C), X-rays, and gamma rays (photons).

Ionizing radiation and radioactive materials are part of our daily lives. We are exposed to ionizing radiation every day from a variety of natural and artificial sources. Natural background radiation exists everywhere: in the soil, water, plants, food, and even in our body. It originates from several sources: cosmic radiation from outside the solar system, solar radiation, radiation from natural sources (many substances on Earth contain radioactive atoms), and from radon gas, which is emitted from the bedrock of buildings and accumulates in the foundations of poorly ventilated homes. Artificial sources are diverse, and people are exposed to them through consumer products such as tobacco (which contains ²¹⁰Po), watches containing tritium, eyeglass lenses, television screens, security scanners, smoke detectors, sensors, building materials, fuels (gas and coal), as well as through medical procedures such as diagnostic X-rays, nuclear medicine, and radiotherapy.

How does ionizing radiation affect us?

At low levels, the effect of ionizing radiation can be so minimal that it is almost impossible to detect through epidemiological studies.

Radiation can cause damage to the genetic material (DNA) in every cell of our body. Our cells respond to radiation damage in several ways: they may efficiently repair the damage, destroy the damaged cell, or replace it as part of the body’s natural renewal process. Nevertheless, there remains a very small chance that some damaged cells will persist rather that being repaired or dying.

There are international standards and regulations for environmental protection and the handling of radiation, designed to protect anyone exposed to radiation at work or in any other context, such as medical procedures. S.R.Y. is committed to complying with all radiation safety regulations, constantly prioritizing the safety of patients and staff.

It is important to understand that although exposure to ionizing radiation occurs during certain medical procedures (diagnosis or treatment), the benefit of the treatment or early diagnosis largely outweighs the potential harm from such exposure. Many people around the world owe their lives to the use of medical radiation.

הפוסט Ionizing Radiation הופיע לראשונה ב-ש.ר.י.

The cyclotron was invented in the early 1930s by the American scientist Ernest Lawrence, who was awarded the Nobel Prize in Physics in 1939 for this invention. From its invention until the mid-1940s, the cyclotron dominated the field of high-energy accelerators. Even today, with much more powerful accelerators available, cyclotrons are still used for certain research and practical purposes, including production of radioactive isotopes for preparation of various diagnostic radiopharmaceuticals.

The cyclotron consists of two half-cylinders, each called “Dee” (due to their shape, which resembles the letter D), with different electric potentials, thus creating an electric field between them, which accelerates charged particles as they pass through. A magnetic field is present across the entire cyclotron, including the Dees, which causes the charged particles to move in a circular motion, bringing them repeatedly back to the acceleration region. Because the rotation frequency of a charged particle in a magnetic field does not change with its speed, an electric field that oscillates at the same frequency is oriented to accelerate the charged particle towards the other half-cylinder every time the particle exits one of the Dees.

Cyclotrons are mainly used to produce radioactive isotopes by bombarding stable nuclei (isotopes) with particles such as protons and deuterium nuclei, which have sufficient energy to overcome the repulsive forces between them and the target nuclei. This bombardment creates a nuclear reaction, allowing the nuclei to merge (with or without emission of other particles) to form a new type of nucleus. This process has been vital for studying nuclear structure and the interactions governing it, and has yielded important reaction products (isotopes). In this way, radioactive isotopes of known atoms were first produced and put to use in various applications, including medical needs. Later, new elements were discovered by this method, the first being technetium, followed by transuranic elements, most notably plutonium. Today, cyclotrons are used for producing radioactive isotopes, mainly for medical purposes, as well as for various applied research needs.

Currently, there are four cyclotrons in Israel. Two of them are located at Hadassah Ein Kerem Hospital and are operated by S.R.Y. The devices are used for ongoing production and research purposes. The majority of production is dedicated to fluorine-18, which is used to label numerous radiopharmaceuticals for hospitals across Israel for the diagnosis of cancer and other diseases using PET (positron emission tomography) imaging.

הפוסט Cyclotron הופיע לראשונה ב-ש.ר.י.

Currently, there are hybrid PET-CT and PET-MRI scanners that combine PET scan with CT or MRI, respectively. Not only does the CT/ MRI component provide crucial anatomical information, but it also enhances the quantification of PET data. Both CT / MRI and PET scans are performed on the same device. While the PET scan yields functional information (e.g., blood flow to an organ, its level of function, or the expression of a particular protein), the CT/ MRI scan provides anatomical information about the structure and location of organs, tumors, etc. Because both scans are performed using a single device, they deliver comprehensive information facilitating disease diagnosis, staging, and identification of unique molecular markers for various disease states.

For these reasons, and despite the relatively high costs of PET, this modality is commonly employed.

הפוסט PET – Positron Emission Tomography הופיע לראשונה ב-ש.ר.י.