Glossary of Terms

Breast Module

Adjuvant breast Radiation therapy given after primary cancer radiation treatment to increase the chances of cure, or decrease the risk of local recurrence. Anthracycline An antibiotic, such as daunorubicin®, doxorubicin®, chemotherapy and epirubicin®, that is made from the fungus Streptococcus peucetius and used for cancer treatment. Aromatase inhibitors Many breast tumours are ‘estrogen sensitive’, (AIs) meaning that the hormone estrogen enhances their growth. Aromatase inhibitors such as anastrazole (Arimidex®), exemestane (Aromasin®), and letrozole (Femara®) can block the growth of these tumours by lowering the amount of estrogen in the body. Ascites Abnormal accumulation of serous fluid in the spaces between tissues and organs in the cavity of the abdomen (also called hydroperitoneum). BRCA 1 A tumour-suppressor gene that repairs chromosomal damage, thereby regulating the cycle of cell division by preventing cells from growing and dividing too rapidly or in an uncontrolled way. Certain mutations confer a high probability (85% lifetime risk) of developing breast cancer, and others cause ovarian cancer. Familial mutations of this gene are particularly common among people in the Ashkenazi Jewish ethnic group. BRCA2 A tumour-suppressor gene that repairs chromosomal damage, thereby regulating the cycle of cell division by keeping cells from growing and dividing too rapidly or in an uncontrolled way. Mutations of the BRCA2 gene appear to confer a high risk of early onset breast cancer, but do not carry a substantial elevated risk of ovarian cancer. Calcification Deposits of calcium in the tissues; calcification in the breast can be seen on a mammogram, but cannot be detected by touch. There are two types of breast calcification: macrocalcification and microcalcification.

Macrocalcifications are large deposits and are usually not related to cancer. Microcalcifications are specks of calcium that may be found in an area of rapidly dividing cells. Many microcalcifications clustered together may be a sign of cancer. Clinical target volume Tumour volume that contains the Gross Target (CTV) Volume (GTV) and subclinical microscopic disease. Core biopsy A procedure in which a needle is used to remove a sample of breast tissue or fluid for examination under a microscope. Digitally reconstructed A computer-generated projection image obtained radiograph (DRR) from CT data that serves as a reference for transferring a 3-D treatment plan to the clinical treatment setting. Ductal carcinoma in A noninvasive, precancerous condition in which situ (DCIS) abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, DCIS may become invasive cancer and spread to other tissues, although it is not known at this time how to predict which lesions will become invasive. DCIS is also called intraductal carcinoma. Edema An accumulation of an excessive amount of watery fluid in cells, tissues, or serous cavities. Erythema Abnormal redness of the skin due to capillary congestion and dilation; often a sign of inflammation or infection. Estrogen receptors Intracellular protein molecules containing a specific site to which estrogens (or closely related molecules) can bind. Target tissues affected by estrogen molecules all contain estrogen receptors; other organs and tissues in the body do not. These proteins are present in many breast cancer cells and are important in the progression of hormone-dependent cancers. Gross tumour volume Gross palpable or visible extent and location of (GTV) malignant growth. Hormone receptor Indicates the presence or absence of hormone status receptors. A cancer is called ‘ER-positive’ if it has receptors for the hormone estrogen. It is called ‘PR-

positive’ if it has receptors for the hormone progesterone. Cells lacking such receptors are considered ‘negative’ for these hormones. Hyperpigmentation Excess pigment in skin or tissue. Invasive cancer Invasive or infiltrating cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding tissues. Isodose distribution A ‘map’ of radiation doses across the volume of tissue being treated. Linear accelerator A radiation therapy treatment machine that (“Linac”) accelerates electrons, creating high-energy radiation to treat cancers. Also called a “linac”. Lobule A rounded projection or subdivision of a lobe. In the breast, lobules produce milk. Lumpectomy Surgery to remove a breast tumour and a small amount of surrounding normal tissue. Lymphedema Lymphedema occurs when lymphatic fluid builds up in the soft tissues of the body, due to an injury or blockage of the lymphatic system. It can occur as a result of cancer or after surgery or radiation treatment for cancer, particularly when lymph nodes are removed or damaged. Mastectomy Surgical removal of all or part of the breast and sometimes associated lymph nodes and muscles. Metastasis The spread of cancerous cells from the initial area to other parts of the body. A tumour formed by cells that have spread is called a “metastatic tumour” or a “metastasis”. A metastatic tumour contains cells that are like those in the original (primary) tumour. The plural form of metastasis is metastases. Neo-adjuvant Chemotherapy given before the primary treatment. chemotherapy Photon A quantum of electromagnetic radiation; the elementary particle of photon radiation therapy. X rays and gamma rays are photon radiation. Planning target The geometric radiation target where dose is to be volume (PTV) delivered. The PTV contains the Clinical Target Volume (CTV) plus a margin around it to allow for treatment setup variation and internal target motion.

Portal imaging The documentation of treatment fields through radiographic images or electronic portal imaging devices. Radiation pneumonitis An interstitial pulmonary inflammation developing in as many as 5-15% of patients with thoracic irradiation, for example due to breast and lung cancer. Acute radiation pneumonitis tends to occur within 6 months following treatment. Sentinel node biopsy A sentinel lymph node (SLN) is the first lymph node to which cancer cells are likely to spread from the primary tumor. Cancer cells may appear in the sentinel node before spreading to other lymph nodes, and a biopsy or sample of these nodes can be used to help determine the extent or stage of cancer. Side effects Symptoms directly related to treatment, such as nausea resulting from radiation treatment of the stomach. Side effects are considered acute if they occur within the first six months after treatment. Symptoms persisting over a longer period of time are considered chronic. Simulation A simulation machine (simulator) is a radiographic X machine/CT-simulator ray unit that mimics all the movements and parameters of actual treatment units. A CT-simulator is a computerized tomography scanner specifically designed for treatment planning. Staging Assessing the extent of the primary tumour and whether there is spread of cancer to the draining lymph nodes or distant body sites. Systemic treatment Treatment using substances that travel through the bloodstream. Tamoxifen An anti-estrogen drug used to treat breast cancer and to prevent it in women who are at high risk of developing breast cancer. Tamoxifen blocks the effects of the hormone estrogen in the breast. Tangents A parallel-opposed pair of treatment beams that treats a curved volume, such as the breast along an angle that is tangential to the chest wall. Tumour grade A measure of the degree of severity of a cancer tumour; the grade of a tumour depends on how abnormal the cancer cells look under a microscope

and how quickly the tumour is likely to grow and spread.

UICC - Union The mission of the International Union Against Cancer Internationale Contre is to build and lead the global community engaged in Le Cancer sharing and exchanging cancer control knowledge and competence equitably; transferring scientific findings to clinical settings; systematically reducing and eventually eliminating disparities in prevention, early detection, treatment and care of cancers, and delivering the best possible care to all cancer patients.