| Abnormal growths of cells that divide uncontrollably and can invade nearby tissues. | Cancerous Tumours |
| What characteristic of cancer cells makes them more vulnerable to radiation? | Cancer cells divide faster than healthy cells. |
| Radiation that carries enough energy to liberate electrons from atoms or molecules, leading to cell damage or death. | Ionizing Radiation |
| What type of radiation can be used to treat cancerous tumors? | Ionizing radiation. |
| A type of radiotherapy in which radiation sources are placed inside the body, usually close to or within the tumor. | Internal Radiotherapy |
| How is internal radiotherapy administered? | Internal radiotherapy uses beta sources placed inside the body, usually near the target tumor. |
| A source of radiation emitting beta particles, which are high-energy electrons. | Beta Source |
| Why must the beta source be placed inside or very near the target tumor in internal radiotherapy? | To ensure that only the tumor is affected and not any healthy cells nearby. |
| A type of radiotherapy in which radiation beams are directed at the tumor from outside the body. | External Radiotherapy |
| How is external radiotherapy administered? | External radiotherapy uses beams of gamma rays, X-rays, or protons directed at the tumor from outside the body. |
| High-energy electromagnetic radiation emitted during radioactive decay. | Gamma Rays |
| What type of radiation is used in external radiotherapy? | Beams of gamma rays, X-rays, or protons. |
| The amount of radiation or medication administered during a specific period. | Dose |
| How does external radiotherapy reduce the dose for surrounding healthy tissue? | By directing radiation beams at the tumor from multiple directions, ensuring that the tumor receives a full dose while minimizing exposure to surrounding healthy tissue. |
| Substances that emit radiation due to the presence of unstable atomic nuclei. | Radioactive Substances |
| How can radioactive substances be used in medical diagnosis? | Radioactive substances can be used to diagnose medical conditions without invasive procedures. |
| Molecules containing a radioactive isotope that are used to track processes within the body. | Radioactive Tracers |
| What are radioactive tracers? | Radioactive tracers are molecules usually used by the body, but containing a radioactive isotope. |
| A device used to detect and image gamma radiation emitted by radioactive tracers in the body. | Gamma Camera |
| How is the radiation emitted by a radioactive tracer detected? | A gamma camera is used to detect the radiation emitted by the tracer. |
| Bleeding that occurs inside the body, typically not visible externally. | Internal Bleeding |
| What medical condition can be diagnosed using radioactive tracers? | Internal bleeding can be diagnosed using radioactive tracers. |
| The ability of an organ to perform its physiological functions effectively. | Organ Function |
| What can doctors determine by tracking the path of a radioactive tracer? | Doctors can determine whether organs are working correctly by tracking the path of a radioactive tracer. |
| Glucose molecule containing a radioactive isotope, used as a tracer to detect cancer tumors. | Radioactive Glucose |
| Why can radioactive glucose be used to detect cancer tumors? | Cancer tumors can be detected using radioactive glucose as a tracer because tumors use more glucose than other cells due to their increased energy demands. |
| Subatomic particles with the same mass as electrons but with a positive charge. | Positrons |
| What can be used to diagnose medical conditions besides radioactive tracers emitting gamma rays? | Tracers emitting positrons can also be used. |
| Another name for a positron, a positively charged subatomic particle. | Antielectron |
| What is another name for a positron? | An antielectron. |
| The process by which a positron and an electron collide and are both destroyed, resulting in the emission of two gamma rays. | Annihilation |
| What happens when a positron meets an electron in the patient's body? | Both particles are destroyed in a process called annihilation, resulting in the emission of two gamma rays. |
| Positron Emission Tomography scanner, a medical imaging device used to detect positron-emitting radioactive tracers in the body. | PET Scanner |
| What medical imaging device is used to detect gamma rays emitted from the annihilation of positrons and electrons? | A PET scanner. |
| The process of using computer algorithms to create visual representations of the distribution of radioactive tracers in the body. | Image Reconstruction |
| How does a PET scanner create a complete image of tracer distribution in the body? | The PET scanner moves around the patient to collect data from multiple angles, which is then used in image reconstruction to build up a complete image. |
| Substances containing a radioactive isotope that are used to track processes within the body for medical purposes. | Radioactive Tracers |
| Why do radioactive tracers used in medicine need to have a short half-life? | Radioactive tracers with a short half-life reduce the amount of time a patient is exposed to radiation. |
| The time it takes for half of the radioactive atoms in a substance to decay into a more stable form. | Half-Life |
| What happens to radioactive tracers with a short half-life? | They lose their radioactivity quickly. |
| The process by which unstable atomic nuclei lose energy by emitting radiation. | Decay |
| Why must radioactive tracers with a short half-life be used shortly after they're made? | They lose their radioactivity very quickly due to decay. |
| Where are radioactive tracers typically made, and why? | They are made at the hospital or in facilities very close by, because they lose their radioactivity quickly. |
