Prostate Cancer Glossary

Adjuvant: Assisting or aiding. Used to describe additional treatments administered in addition to a definitive therapy. For EBRT this usually refers to androgen deprivation given after ERBT is finished.

Androgen: A hormone with masculinizing properties, for example, testosterone. Androgens stimulate growth of both normal prostate and most malignant prostatic cells.

Androgen Deprivation: A therapeutic strategy designed to decrease circulating levels of the male androgen testosterone, and its related compounds. Can be done by removing organs that produce testosterone (for example, testicles, called orchiectomy), or by giving medication (See hormone therapy).

Anti-androgen: Oral agents flutamide (Eulexin), nilutamide (Nilandron) and bicalutamide (Casodex), that block the action of testosterone and its active metabolite dihydrotestosterone (DHT) at the cellular level by interfering with androgen receptor interactions.

Anti-Androgen Withdrawal (AAWD): A clinical syndrome in which discontinuation of an anti-androgen in a patient may result in a decline in PSA, symptomatic improvement or tumor regression; effective in 15 to 30 percent of patients for a short time.

Applicator: A device used to deliver or hold a radioactive source during brachytherapy.

Benign Prostatic Hyperplasia (BPH): Non-cancerous enlargement of the prostate gland, which often results in difficulty with urination. The incidence increases with age.

Biopsy: Sampling of tissue.

Blocks: Pieces of metal alloy that can be used to shape the EBRT beam.

Bone Scan: A nuclear medicine imaging study that utilizes a radioactive compound that is injected into a vein to identify areas of increased bone cell activity in the skeleton; used to screen for the presence of bone metastases.

Boost: An additional dose of radiation that is given after an initial course of treatment, to enhance tumor control.

Brachytherapy: In radiation therapy, treatment with ionizing radiation that is applied directly into an organ that has cancer. For prostate cancer, this consists of implantation of radioactive seeds though thin tubes into the prostate. Also called "implants".

Cancer: A group of diseases characterized by uncontrolled cell growth. Cancer cells, unlike benign cells, exhibit the properties of invasion and metastasis.

Catheter: A general term for a tube that is inserted to drain fluids from or instill fluid into the body.

Cell: The fundamental structural and functional unit of living organisms.

Clinical Trials:

  • Phase I: A clinical trial designed to determine the appropriate dose and toxicities of an investigational agent or treatment.
  • Phase II: A clinical trial designed to determine the effectiveness and side effects of an investigational agent or regimen.
  • Phase III: A clinical trial designed to test the effectiveness of a given treatment as compared to existing treatments.
  • Phase IV: Phase IV clinical trials are conducted after a drug has been approved to learn more about the side effects, long-term benefits and risks and widespread efficacy of a drug or treatment.

Combined Androgen Blockade (CAB): "Hormone therapy"; testosterone blockade achieved with the combination of medical or surgical castration and an antiandrogen.

Computerized tomography (CT or CAT scan): Computer assisted tomography. A radiologic imaging study in which cross-sectional images of the body are obtained. For EBRT, CT scans are used for treatment planning.

Concurrent: This means simultaneous. With EBRT, usually refers to androgen deprivation that is given during the course of treatment.

Controls: A standard against which experimental observations may be evaluated, as a procedure identical in all respects to the experimental procedure, except for absence of the one factor that is being studied.

Dihydrotestosterone (DHT): A derivative of testosterone, which has a higher biologic activity within the prostate than testosterone; blocked by 5-alpha reductase medications, such as finasteride (Proscar) and dutasteride (Avodart).

Electronic Portal Image (EPI): An electronic image produced using a flat panel.

Epidural Catheter: Catheter inserted into the space surrounding the spinal cord; used after radical prostatectomy or during HDR brachytherapy to instill medication to block pain.

Epithelium: Cells that line body surfaces and cavities. These are the cells that produce secretions, such as PSA in the prostate and are the cells from which carcinomas are derived.

Erectile Dysfunction (ED): See Impotence

External Beam Radiation Therapy (EBRT): High-energy X-rays or protons used to kill cancerous tissue in the prostate, and elsewhere in the body.

5-Alpha Reductase Inhibitor: A medicine that blocks conversion of testosterone to dihydrotestosterone; inhibits prostate growth.

Flat Panel: A sensitive device that detects x-rays. The image produced is digital and can be immediately processed electronically. Image production requires less energy than port films. May be used to position patients and/or detect organ motion.

Foley Catheter: A tube that is placed into the bladder, used to drain urine.

Gantry: The part of the linear accelerator that moves around the patient and functions in the delivery of EBRT.

Gleason Grade and Score: A numerical value given to prostate cancers that describes tumor grade. Grades are assigned to the most common pattern of cancer as well as the second most common. Grades for each pattern range from 1 to 5. A grade of 1 denotes a cancer that closely resembles benign or normal tissue. A grade of 5 is assigned to cancers that appear most aggressive and differ significantly from benign tissue. The Gleason score is obtained by adding together the 2 Gleason grades, and can range from 2 to 10.

Gray (Gy): A unit of absorbed energy dose.

Gynecomastia: Enlargement of breast tissue in a man. May occur with the use of androgen deprivation.

High Dose Rate Brachytherapy (HDR): A focal radiotherapy treatment involving temporary placement of a radioactive source in the prostate that is removed after each treatment. Small flexible tubes are inserted into the prostate through the perineum to deliver a high dose of radiation in a short period of time (5 to 20 minutes).

Hormone Therapy: See androgen deprivation.

Immobilization Device: An external device used to help the patient remain in the same position for every treatment.

Impotence: Erectile dysfunction. The inability to achieve an unassisted erection sufficient for satisfactory sexual intercourse.

Intensity Modulated Radiation Therapy (IMRT): An advanced form of 3D-CRT (see below) that selectively raises doses at different places on the prostate and spares normal tissue with great precision.

Interstitial Implant: A type of brachytherapy in which radioactive material ("seeds") are implanted into the prostate.

Ionizing Radiation: A general term for particle beams that trigger ionization (excitation) of an atom or molecule. Ionizing radiation transfers energy into the tissues where it is deposited.

Laparoscopy: A surgical technique in which small incisions are made in the body in order to introduce specially designed telescopes and instruments.

Linear Accelerator ("Linac"): A machine used to deliver EBRT.

Luteinizing Hormone Releasing Hormone (LHRH) Agonist: Synthetic analogs of natural gonadotropin-releasing factor which induce a temporary increase in testosterone secretion followed by fall of testosterone to castrate levels.

Lymph Node: Filter nodules that are part of the body's drainage system for fluids. Also serve as a component of the immune system by removing bacteria, foreign particles, and cancer cells, etc. from the circulation. Often the site of tumor metastases.

Metastasis: Secondary growth of a cancer due to the spread of cancer cells away from the site of origin. The capacity to metastasize is a characteristic of malignant tumors.

Multi-Leaf Collimator ("MLC"): A part of the linear accelerator that is used to shape the EBRT beam.

Neoadjuvant: A treatment that is given before definitive local therapy. For EBRT usually refers to androgen deprivation given before the start of treatment.

Orchiectomy: Surgical removal of the testicles to eliminate testosterone; used to treat advanced prostate cancer.

Osteoblastic: Term describing the type of bone metastasis associated with metastatic prostate cancer. These lesions are characterized by abnormal bone generation (osteoblastic) rather than bone loss (osteolytic).

Osteopenia: Decreased calcification or density of bone.

Osteoporosis: A reduction in the quantity or amount of bone; skeletal atrophy.

Partin Tables: A set of published tables that uses preoperative PSA, Gleason score, and clinical stage to predict pathologic stage.

Pelvic Lymph Node Dissection: Removal of the lymph nodes in the pelvis, which filter body fluids from the prostate, bladder and rectum. The nodes may be removed during radical prostatectomy and examined for the presence of cancer cells.

Perineum: The area of the body between the anus and the base of the scrotum. In brachytherapy, needles containing radioactive seeds or in HDR, thin tubes are implanted in the prostate through the perineum.

Prostascint® : A monoclonal antibody imaging study used to detect prostate cancer cells in the soft tissues of the body.

Prostate Gland: A gland in the male, which surrounds the neck of the bladder and urethra. Secretions produced in the prostate contribute to the seminal fluid.

Prostate Specific Antigen (PSA): A protein produced by prostatic epithelial cells. The level of PSA often correlates with the likelihood and extent of prostate cancer and the size of the benign prostatic enlargement or BPH.

PSA Nadir: The lowest point to which a patient's PSA drops following definitive treatment, which is usually used in the context of radiation therapy.

Prostatic Intraepithelial Neoplasia (PIN): A precancerous lesion of the prostate.

Peripheral Zone (PZ): The rear, outer area of the prostate gland where over 80 percent of prostate cancers originate.

Radiation Oncologist: A physician who specializes in treating cancer with radiation therapy.

Radiation Therapist: A person who is specifically trained to operate the linear accelerator and administer radiation therapy treatments.

Radical Prostatectomy: A surgery in which the entire prostate gland and adjacent seminal vesicles are removed.

Randomized Clinical Trial: A clinical trial in which the effectiveness of two or more treatments is compared. Patients are randomly assigned to treatments being tested to ensure that clinical features are balanced.

Seminal vesicles: Paired glands located on either side of the prostate that secrete substances to nourish sperm.

Simulation: The process of planning radiation therapy. For EBRT, usually includes X-rays and a CT scan.

Testosterone: The male sex hormone or androgen that causes characteristically male features; predominantly produced in the testicles.

Three-Dimensional Conformal Radiation Therapy (3D-CRT): A means of delivering external beam radiation therapy resulting in high doses being delivered to the target with less exposure to surrounding tissue.

Transrectal Ultrasound: An imaging test in which an ultrasound probe is placed into the rectum to image the entire prostate. This test facilitates prostate cancer staging and prostate biopsy.

Transition Zone (TZ): The inner zone of prostate that surrounds the urethra. In general, few prostate cancers originate here; however, it is the area where benign prostatic enlargement occurs.

Treatment Plan: A radiation oncologist's prescription that describes how a patient should be treated, including the dose of radiation to be delivered, and the organs to be treated and protected.

Urethra: A structure that drains urine from the bladder. It passes through the prostate gland (prostatic urethra) and through the penis (penile urethra).

Urinary Incontinence: Uncontrolled loss of urine.


Reviewed by health care specialists at UCSF Medical Center.

This information is for educational purposes only and is not intended to replace the advice of your doctor or health care provider. We encourage you to discuss with your doctor any questions or concerns you may have.

Related Information

UCSF Clinics & Centers

Helen Diller Family Comprehensive Cancer Center

Prostate Cancer Center
1825 Fourth St., Fourth Floor
San Francisco, CA 94158
Medical Oncology Phone: (415) 476-4616
Surgical Oncology Phone: (415) 353-7171
Medical Oncology Fax: (415) 353-7107
Surgical Oncology Fax: (415) 514-6195

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