Below we have listed (alphabetically) some of the most common terms used in the diagnosis or treatment of childhood cancer and given a brief explanation of each.
If you don’t understand the words used by someone who is speaking to you about the health of your child, you should never feel embarrassed to ask the person to explain them to you. This includes our own Family Support Team.
Acute
A condition that develops quickly. In cancer, “acute” does not mean more dangerous — just faster-growing.
Anaesthetic
Medicine that helps a child sleep deeply or feel no pain during tests or procedures.
Benign
Non-cancerous. Benign tumours do not spread to other parts of the body.
Biopsy
A small sample of tissue taken to understand what type of cells are present. This helps confirm the diagnosis.
Bone Marrow
The soft, spongy tissue inside bones where blood cells are made.
Central Line / Port
A small, flexible tube placed under the skin or into a large vein. It makes it easier to give treatment and take blood samples without repeated needles.
Chemotherapy
Medicines that destroy cancer cells or stop them growing. Chemotherapy can be given through a central line, as tablets or sometimes into the spinal fluid.
CT Scan (Computed Tomography)
A type of scan that uses X-rays to create detailed pictures of inside the body.
Endocrine System
The glands and hormones that control growth, metabolism and development. Some rare childhood tumours start in these glands.
Genetic Testing
A test to look for changes in a child’s DNA. This can help understand how a cancer behaves or whether it has an inherited cause.
Immunotherapy
Treatment that helps the immune system recognise and attack cancer cells. Used in some cancers such as neuroblastoma and certain lymphomas.
Intrathecal Treatment
Chemotherapy given into the fluid around the spinal cord to protect the brain and spine from cancer cells.
Localised Cancer
A cancer that is contained in one area and has not spread elsewhere.
Malignant
Cancerous. A malignant tumour can grow and sometimes spread.
Metastasis / Metastatic
When cancer spreads from where it started to another part of the body.
MRI Scan (Magnetic Resonance Imaging)
A scan that uses magnets and radio waves to create detailed images of the body. Particularly useful for brain and soft-tissue tumours.
Oncologist
A doctor who specialises in treating cancer. Children are treated by paediatric oncologists, who focus solely on childhood cancers.
PET Scan (Positron Emission Tomography)
A scan showing areas of active cancer cells in the body. Often used in lymphoma and some other cancers.
Radiotherapy
A treatment that uses high-energy beams to destroy cancer cells. Carefully targeted to protect healthy tissues as much as possible.
Relapse
When a cancer returns after treatment.
Remission
No evidence of cancer on tests. Remission can be temporary or long-term.
Side Effects
Temporary problems caused by treatment, such as tiredness, hair loss, sickness or low blood counts. Teams work closely to prevent and manage these.
Stem Cell Transplant
A treatment that replaces damaged bone marrow with healthy stem cells. Used for some high-risk or relapsed cancers.
Targeted Therapy
Medicines that focus on specific changes in cancer cells. Often have different side effects to chemotherapy.
Tumour Markers
Substances (often proteins) found in blood or urine that can help diagnose or monitor certain cancers, such as germ cell tumours or liver tumours.
Ultrasound
A scan using sound waves to create images of the inside of the body. Often used for tummy, kidney or pelvic lumps.
White Cell Count
A measure of the body’s infection-fighting cells. Often affected by both cancer and its treatment.
Important Notice
This page is intended to back up the information you get from the hospital, not to replace medical advice from a consultant.
Information last reviewed on 14th January 2026.
Based on information originally produced by Children’s Cancer and Leukaemia Group (CCLG), Accessed 2022.
