Nuclear Medicine
Nuclear Medicine is explained in the Voumed medical encyclopedia. Hospitals in the Voumed network have not listed this specialty yet.
Nuclear medicine uses small amounts of radioactive substances, called radiotracers or radiopharmaceuticals, to show how organs and tissues are working and, in some cases, to treat disease from within. On the diagnostic side it includes PET-CT scans that stage and follow cancer, bone scans, thyroid scans, heart perfusion scans and brain scans for movement disorders. On the treatment side it delivers radiation directly to diseased cells, for example radioactive iodine for thyroid conditions and targeted therapy for selected advanced prostate and neuroendocrine cancers. International patients travel for it to reach specialised tracers and treatments that are not available near home and to have scans and therapy planned together by one department.
Key takeaways
- Nuclear medicine scans show function rather than only structure, so they can reveal active disease, such as cancer spread or areas of poor heart blood flow, that other scans may not show clearly.
- PET-CT with FDG or PSMA tracers is widely used to stage cancer, check the response to treatment and look for recurrence, and the right tracer depends on the type of cancer.
- Radionuclide therapy treats disease from inside the body, including radioactive iodine for thyroid conditions and Lu-177 PSMA or DOTATATE for selected advanced prostate and neuroendocrine cancers.
- The radiation dose from a diagnostic scan is small, but after a therapy you may need to limit close contact with others for a period, and the exact rules depend on the treatment and dose.
- Pregnancy and breastfeeding must be discussed before any scan or therapy, and treatment courses involve several visits, so planning together with your home oncology team matters.
On this page
At a glance
- Common tests and procedures
- FDG and PSMA PET-CT, bone scan, thyroid scan, myocardial perfusion scan, DaTscan, radioactive iodine therapy, Lu-177 PSMA and DOTATATE therapy
- Common reasons to travel
- access to specialised tracers or radionuclide therapy, a combined scan and treatment plan, shorter waiting times
- Typical visit or stay
- half a day for most scans, therapy as a day-case or a stay of 1 to 3 days in a shielded room depending on the treatment
- Anaesthesia
- none, as tracers are given by injection or by mouth
- Typical first step
- a remote review of your diagnosis, previous scans and blood results to confirm which scan or therapy suits you
Overview
Nuclear medicine is a specialty that works at the level of body chemistry. A radiotracer is a substance that the body handles in a known way, such as a form of sugar, a hormone building block or a molecule that binds to a particular receptor, linked to a small radioactive label. After it is injected or swallowed, it collects in the tissues that use or carry that target, and a special camera detects the radiation it gives off. This produces images of how organs work, which can show disease before it changes the shape of an organ. The same principle allows treatment: when the label is a stronger, short-range emitter, the radiopharmaceutical delivers radiation directly to the diseased cells while largely sparing the tissue around them. Pairing a scan that finds a target with a therapy that treats it is called theranostics. Nuclear medicine physicians work closely with oncologists, cardiologists, endocrinologists and neurologists.
Conditions and sub-specialties
Cancer is the largest area of work. PET-CT helps to stage lymphoma and lung, colorectal, head and neck and many other cancers, and PSMA PET-CT has changed how prostate cancer is staged and followed. Somatostatin receptor scans, such as Ga-68 DOTATATE PET-CT, map neuroendocrine tumours. Nuclear cardiology uses myocardial perfusion imaging to show whether parts of the heart muscle receive too little blood during stress, which helps to decide whether further tests or procedures are needed. Thyroid nuclear medicine assesses and treats overactive glands and nodules, and manages radioactive iodine treatment after surgery for differentiated thyroid cancer. Bone scans look for cancer spread, hidden fractures and infection. In neurology, DaTscan helps to tell Parkinsonian conditions apart from other tremor disorders, and brain PET may support the assessment of dementia and epilepsy. Kidney scans measure how much each kidney contributes to overall function.
Common treatments and procedures
Radioactive iodine, swallowed as a capsule or a drink, is a long-established treatment for an overactive thyroid, and after thyroid removal it is used to destroy remaining thyroid tissue or spread of differentiated thyroid cancer. Lutetium-177 PSMA therapy targets prostate cancer cells that carry PSMA and is given to selected men with advanced prostate cancer, usually after other treatments, as a course of infusions several weeks apart. Lutetium-177 DOTATATE, a form of peptide receptor radionuclide therapy, treats selected neuroendocrine tumours that show the matching receptors on a scan. For both, a PET-CT first confirms that the tumour takes up the tracer. Radioembolisation of liver tumours with yttrium-90 beads is carried out together with interventional radiology, and radium-223 may be used for some men whose prostate cancer has spread to bone. Each therapy is decided by a tumour board, and its aim, whether control of the disease or relief of symptoms, is discussed openly before you begin.
Diagnostics and technology
The main instruments are gamma cameras and PET scanners. A gamma camera, often combined with CT in a SPECT-CT system, records the tracers used for bone, thyroid, heart, kidney and brain scans, while the CT part pinpoints where the activity lies. A PET-CT scanner detects positron-emitting tracers with higher resolution and is the standard tool for cancer imaging. Tracers matter as much as the scanner: FDG shows sugar use, PSMA tracers find prostate cancer cells, DOTATATE tracers find neuroendocrine tumours, and FAPI tracers, which are still being studied, highlight the supporting tissue around many tumours. Some tracers are made on site and lose their activity within hours, which is why appointment times are fixed and should be kept. Therapy needs shielded rooms, special waste handling and careful dose measurement, and is planned by a team that includes medical physicists.
What to expect as an international patient
Most nuclear medicine care starts with a remote review of your diagnosis, pathology report, recent scans and blood tests, including kidney function and, for prostate cancer, your PSA history. For a scan, you may be asked to fast for a few hours, especially before FDG PET-CT, and people with diabetes receive specific advice beforehand. A scan visit usually lasts half a day, and the report is often ready within one to two days. Therapy is different: radioactive iodine or lutetium treatment may need a short stay in a shielded room, or may be given as a day-case with instructions to limit close contact afterwards. Courses of lutetium therapy usually include several cycles about six to eight weeks apart, so plan either repeated visits or shared care with your home team. You receive a written discharge letter describing the treatment, the dose and the precautions to follow, which is also useful when travelling.
Frequently asked questions
These answers are general guidance and may vary by provider. Confirm the details with the hospital you choose.
Is the radiation from a nuclear medicine scan dangerous?
The dose from a diagnostic scan is small and is chosen to answer a specific clinical question, and the benefit of an accurate diagnosis usually far outweighs the small added risk. Most tracers lose their radioactivity within hours to a day and leave the body in the urine. Drinking plenty of fluids and emptying your bladder often after the scan helps to clear the tracer faster.
What is the difference between an FDG and a PSMA PET-CT?
FDG is a form of sugar, so it highlights tissues that use a lot of glucose, which includes many cancers but also inflammation, the brain and healing tissue. PSMA tracers bind to a protein found on most prostate cancer cells, so they are far more specific for prostate cancer. Your oncology team chooses the tracer according to the cancer type and the question being asked.
Who can have Lu-177 PSMA or DOTATATE therapy?
These treatments are for selected patients whose tumour takes up the matching tracer on a PET-CT scan. Lu-177 PSMA is generally used for advanced prostate cancer that has progressed after other treatments, and Lu-177 DOTATATE for neuroendocrine tumours with somatostatin receptors. Blood counts and kidney function must be adequate. The decision is made by a tumour board after reviewing your scans, your history and your current treatment.
Will I need to stay in isolation after therapy?
It depends on the treatment and the dose. Higher-dose radioactive iodine often means one to three days in a shielded hospital room until the radiation level falls. Lutetium therapy is often a day-case or a one-night stay, depending on local rules. Afterwards you are usually asked to limit close contact, particularly with children and pregnant women, for a number of days, and to follow hygiene advice. Your team gives you written, dose-specific instructions.
Can I fly home after radioactive treatment?
Usually yes, once the team agrees that you can leave. Airports and border crossings may use radiation detectors that can be triggered for days to weeks after treatment, so carry the letter or certificate the department provides, stating the substance, the dose and the date. During the restriction period, avoid sitting next to a child or a pregnant woman on a long flight, and ask the team how many days apply to you.
Is nuclear medicine possible during pregnancy or breastfeeding?
Tell the team as early as possible if you are or may be pregnant, or are breastfeeding. Therapies are generally not given during pregnancy, and pregnancy is usually advised against for a period after treatment, often several months, depending on the substance. Some scans can still be done with precautions when the benefit is clear. Breastfeeding often needs a pause after a scan, and it must stop several weeks before radioactive iodine therapy and is not restarted for that child.
How should I prepare for a PET-CT scan?
For an FDG scan you usually fast for about 4 to 6 hours, avoid hard exercise the day before and drink water. People with diabetes need specific advice on food and medicines so that blood sugar is in range. PSMA and DOTATATE scans usually need less preparation, although some medicines may need to be timed around the scan. Plan for two to four hours in the department.
How does care continue after I return home?
You leave with a written report or discharge letter that includes the scan findings or the treatment given, the dose and the precautions to follow. Blood tests to check blood counts and kidney function are usually needed in the weeks after therapy, and these can be done near home and shared with the team. Follow-up scans are often planned after the course to see how the disease has responded.
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