· R01 Grant A Research Project Grant awarded by the National Cancer Institute. This type of grant provides support for a specific research project initiated by an investigator in the field.
· RA Research Assistant; Research Associate.
· radiation oncologist A physician who specializes in the use of radioactive substances and x-rays for the treatment of tumors and cancer.
· radiation therapist A health professional who gives radiation therapy as part of a team led by a radiation oncologist.
· radiation therapy The use of radiation energy to interfere with tumor growth. Also called irradiation.
· radical Radical surgery is the resection of a tumor and a wide margin around the tumor in an attempt to remove any spreading cells.
· radioactive Giving off radiation.
· radioactive monoclonal antibodies An antibody is a substance produced by white blood cells in response to a foreign object (an antigen). The human body often considers tumor cells to be foreign objects because they have unique proteins (antigens) Because an antibody binds only to a specific antigen, it can act as a homing device to a tumor cell. Monoclonal antibodies, manufactured in large quantity in the laboratory, can be mated to radioactive isotopes which kill tumor cells.
· radioisotope An unstable element that releases radiation as it breaks down. It can be used in imaging tests or as a treatment for cancer. Also called isotope.
· radiolabeled Any material that has been joined to a radioactive substance.
· radiologist A physician trained in the use of , x-rays, and other imaging techniques to arrive at a diagnosis.
· radionuclide scanning A technique to produce images of internal parts of the body. A small amount of radioactive material is injected or swallowed. A scanning machine then measures the radioactivity in certain organs.
· radioprotectors Drugs used to protect normal brain cells from the effects of radiation therapy.
· radioresistant Resistant to radiation therapy.
· radiosensitive Responsive to radiation therapy.
· radiosensitizers Drugs used before or during radiation therapy to make tumor cells more sensitive or vulnerable to radiation therapy.
· radiosurgery Stereotactic radiosurgery. A special, focal form of radiation therapy that uses a large number of narrow, precisely aimed, high dose beams of ionizing radiation. The beams are aimed from many directions circling the head to meet at the tumor. The treatment is delivered in one session. Stereotactic radiotherapy or fractionated stereotactic radiosurgery (FSRS) is stereotactic radiosurgery delivered in multiple fractions over a period of time. Stereotactic radiosurgery is commonly abbreviated SRS.
· RAID Rapid Access to Intervention Development. A program of the National Cancer Institute (NCI) to facilitate translation to the clinic of novel, scientifically meritorious therapies originating in the academic community.
· randomized study A study having two or more “arms.” The treatment arm (standard versus new) assigned to each patient is determined by a computer. Randomization is used to prevent bias and ensure that an equal number of patients are assigned to each arm of the study.
· rate A measure of the amount of a disease in a specific
population, calculated by counting the number of patients with the disease and dividing by the total population at risk. Rates are expressed as a unit of person-years (usually 100,000). A person-year is one person for one year.
· rCBV [r c b v] Acronym for regional Cerebral Blood Volume, a measure of the flow of oxygenated blood through the brain.
· RCT Randomized Clinical Trial.
· RD Registered Dietician.
· real time MRI This technique produces MRI images in a faster sequence than traditional MRIs. The increased speed permits the visualization of the use of oxygen by the tumor and the brain tissue. This technique is important because it depicts an area of the brain “lighting up” when the patient performs a task, such as moving a finger, or speaking. In this way, brain maps of functional areas are generated, useful for preoperative surgical planning and intraoperative avoidance of functional or “eloquent” areas of the brain. Also called echoplanar, functional, or Fast MRI.
· receptor-mediated permeabilizers A way of delivering drugs through the blood brain barrier. Receptor-mediated permeabilizers are synthetic substances modeled after naturally occurring compounds. These substances temporarily increase the openings of the blood brain barrier, allowing drugs to pass into the brain. Abbreviated RMP.
· RECIST Response Evaluation Criteria in Solid Tumors. A set of rules that defines when tumors shrink (respond), stay the same (stable), or grow (progress) during treatment. Clinical trials investigating new treatments often use RECIST to evaluate response to treatment. The basic criteria (simplified) are:
o Complete Response (CR): Disappearance of a tumor(s)
o Partial Response (PR): At least a 30% decrease in the diameter of a tumor
o Progressive Disease (PD): At least a 20% increase in the diameter of a tumor
o Stable Disease (SD): Neither PR nor PD
· recurrence Reappearance of the tumor. The return of symptoms or the tumor itself, at the same site as the original (primary) tumor or in another location, after the tumor had disappeared for a time.
· red blood cells Cells that carry oxygen to all parts of the body. Also called erythrocytes or RBCs.
· registered nurse A trained professional who assists people with their healthcare under the direction of a physician. Abbreviated RN.
· rehabilitation The process of restoring mental and/or physical function after illness or injury, often with the assistance of specialized healthcare professionals.
· relapse The return of signs and symptoms of a disease after a period of improvement.
· remission The disappearance of symptoms or the disappearance of the tumor. A remission can be permanent or temporary.
· resectable [re SECT uh bull] Suitable for resection, i.e., surgical removal.
· resection [ree sek´ shun] Surgical removal of a tumor. Often used with an adjective, for example, macroscopic total resection — removal of all visible tumor; partial or subtotal resection — some visible tumor could not be removed.
· reservoirs A small “container” such as an Ommaya Reservoir is surgically placed under the scalp. A tube leads from the eservoir into a ventricle of the brain. Medications are injected via syringe into the reservoir and then the reservoir is pumped. The pumping begins the flow of drug through the ventricles and lining of the spine. Chemotherapy administered this way is usually repeated on a regular schedule.
· resident A medical doctor who has completed medical school and internship, and is receiving further training in a specialized area. Completion of a residency program is required for board certification in a medical or surgical specialty.
· residual tumor [ree zid´ yu al] Tumor remaining after reatment.
· respiration Breathing. To inhale and exhale.
· reticular formation [reh tik´ you lar] A network of nerves in the center of the brain stem.
· retinoid Vitamin A or a vitamin A-like compound.
· RFA Request for Applications.
· RFP Request for Proposals.
· risk/benefit ratio The relationship between possible risks and potential benefits of a treatment. Patients and their families must decide if the ratio is reasonable for them.
· risk factor Anything that increases the chance of developing a disease.
· Ribonucleic Acid One of the two nucleic acids found in all cells. The other is DNA. RNA transfers genetic information from DNA to proteins produced by the cell. RNA directs the manufacture (synthesis) of proteins.
· RN Registered Nurse.
· RNA Ribonucleic Acid.
· robotic surgery [row bot´ ik] An experimental system consisting of a computer, microscope and mechanical arms to hold instruments that assists surgeons when performing delicate and prolonged surgeries.
· ROM Range of motion.
· RPA Recursive Partitioning Analysis. A statistical method of identifying patient subgroups with significantly different survival rates. A tool used to improve the design of clinical trials.
· RPT Registered Physical Therapist.
· RT or XRT Radiation Therapy.
· RTOG Radiation Therapy Oncology Group, an NCI funded clinical cooperative group organized to evaluate various types of radiation therapy for treating adult cancer patients.
· RTT Radiation Therapy Technician.
· RX, Rx Treatment; prescription.