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Home , Nuclear medicine

Cancer Control

Cancer, nuclear , and biology An overview By Nicole Jawerth

A radiotherapy mask keeps a ancers once considered unmanageable higher doses. Confirmation of the type of patient’s head still to ensure Cand fatal can now be diagnosed earlier tumour, as well as of its size, location and radiation consistently and and treated more effectively using nuclear extent of spread, is essential to selecting accurately hits the precise medicine and , giving the appropriate treatment approach, such target area during treatment. patients a better quality of life and, for as , radiotherapy, chemotherapy or (Photo: D. Calma/IAEA) many, a significant possibility of being immunotherapy, that is used either alone cured. These developments can be or in combination. When radiotherapy is attributed to advances in research and appropriate, it is necessary to select the dose innovations in technology, which are required carefully and to deliver it to the becoming increasingly accessible. tumour with accurately calibrated equipment to maximize the effectiveness of the process But cancer remains a that is on the while minimizing harm. The science of rise globally, having claimed the lives of measuring, calculating and assessing 9.6 million people in 2018, a number that is absorbed doses of radiation is called expected to increase, with an estimated 16.3 dosimetry (see page 14). million deaths predicted worldwide in 2040.

Cancer occurs when cells in the body grow Nuclear medicine and divide abnormally and uncontrollably, Nuclear medicine is a branch of medicine that often forming clusters called tumours. involves the use of to Tumours can be diagnosed using small diagnose and, in some cases, treat amounts of radiation and then treated with such as cancer.

4 | IAEA Bulletin, September 2019 Cancer Control

Radiopharmaceuticals are selected based while minimizing harm to healthy cells. on the location and type of cancer to be Cancer cells often cannot repair damage to evaluated, and whether they are to be their DNA after small doses of radiation as used for diagnosis, treatment or both. efficiently as any normal healthy cells that The is then injected, are in the treatment area. To take advantage inhaled or ingested into a patient’s body. of this biological difference between Once inside the body, it seeks out and then cancerous and healthy cells, a course of gathers near or inside the cancer cells, radiotherapy may be divided into multiple allowing for the evaluation of the tumour small doses over several weeks, giving the location or the delivery of the targeted best chance of destroying the tumour with radiation. Over a known period of time, the the fewest . Understanding the radiopharmaceutical loses its radioactivity. parameters for determining the best treatment regimen in individual situations is part of the For diagnosis, a radiopharmaceutical with science called . very small amounts of radioactive material, termed a ‘tracer,’ is introduced into the Over 14 million people worldwide are body. Once it has collected in or near the diagnosed with cancer each year. Around half cancer cells, a specialized camera is used to of all cancer patients receive radiotherapy detect the radiation that is released, which at some point during their treatment, and is then used to create precise images of it is often used in combination with other what is happening in the patient’s body. methods, such as surgery and chemotherapy. These images help the healthcare team to understand the patient’s condition and plan The IAEA has worked for over 60 years treatment. Images may be taken throughout to promote the use of and advances in the cancer care process to monitor the disease radiation medicine in controlling cancer. It and adjust care accordingly. supports countries worldwide in developing and maintaining their national cancer For treatment, radiopharmaceuticals with care services by training and educating higher amounts of radioactive material are professionals, equipping facilities and selected. The tracer accumulates and delivers facilitating the transfer of scientific Radiopharmaceuticals are the radiation to the cancer cells, where the know-how between experts (see page 22). medical drugs containing radiation damages and kills them. The IAEA also assists with planning, setting radioactive material and can up and reviewing national cancer control be used for diagnosis or In some cases, radiopharmaceuticals are plans, including resource mobilization for treatment purposes. used for both diagnosis and treatment. This projects (see page 18). (Photo: S. Slavchev/IAEA) is called theranostics and is one of the latest advances in cancer diagnosis and treatment (see page 8).

Radiation therapy Radiation therapy, or radiotherapy, is carried out by a team of experts in radiation , medical and radiation therapy technology who are trained to target at cancer cells. Depending on the type and location of the cancer, the team may use external sources of radiation, such as cobalt-60, from a machine that emits radiation, or a linear accelerator that delivers photon radiation using electricity. They may also place radiation sources directly next to or inside of the tumour, which is known as . One of the latest advances in radiotherapy is image guided brachytherapy (see page 10).

Radiotherapy involves carefully selecting doses of radiation that are strong enough to effectively damage DNA in the cancer cells,

IAEA Bulletin, September 2019 | 5