What does Gy mean in radiation therapy?
Standard dose Gray (Gy) is the unit used to measure the total amount of radiation that the patient is exposed to. This can also be recorded as centigray (cGy), which is 0.01 of a single Gy unit. Adjuvant therapy doses typically range from 45 to 60 Gy for the treatment of breast, head, and neck cancers.
How many doses of radiation are needed for cancer treatment?
For most patients that require radiation therapy, the total dose is broken up into daily doses five times a week for a total period of five to eight weeks. Some cancers, however, require treatment more often than once per day. Each fraction contains a small amount of radiation that gradually accumulates to form the total dose.
What is a fraction dose of radiation therapy?
Dose Fractioning. The total radiation dose is usually divided into several fractions. For most patients that require radiation therapy, the total dose is broken up into daily doses five times a week for a total period of five to eight weeks.
What is centigray (cGy) of chemotherapy?
This can also be recorded as centigray (cGy), which is 0.01 of a single Gy unit. Adjuvant therapy doses typically range from 45 to 60 Gy for the treatment of breast, head, and neck cancers.
Radiation Protection
Laws regulate radiation doses to which people can be exposed. The greatest occupational whole-body dose that is allowed depends upon the country and is about 20 to 50 mSv/y and is rarely reached by medical and nuclear power workers. Higher doses are allowed for the hands.
Problem-Solving Strategy
Step 1. Examine the situation to determine that a person is exposed to ionizing radiation.
Risk versus Benefit
Medical doses of radiation are also limited. Diagnostic doses are generally low and have further lowered with improved techniques and faster films. With the possible exception of routine dental x-rays, radiation is used diagnostically only when needed so that the low risk is justified by the benefit of the diagnosis.
Section Summary
The biological effects of ionizing radiation are due to two effects it has on cells: interference with cell reproduction, and destruction of cell function.
Conceptual Questions
Isotopes that emit radiation are relatively safe outside the body and exceptionally hazardous inside. Yet those that emit radiation are hazardous outside and inside. Explain why.
Problems & Exercises
What is the dose in mSv for: (a) a 0.1 Gy x-ray? (b) 2.5 mGy of neutron exposure to the eye? (c) 1.5 mGy of exposure?
What is the unit used to measure the total amount of radiation that the patient is exposed to?
Gray (Gy) is the unit used to measure the total amount of radiation that the patient is exposed to. This can also be recorded as centigray (cGy), which is 0.01 of a single Gy unit.
How long does radiation therapy last?
Standard treatment with radiation therapy lasts for five to eight weeks, depending on the specific type of cancer being treated, and is at the discretion of the oncologist supervising the therapy.
Why is radiation therapy important?
By Yolanda Smith, B.Pharm. Reviewed by Benedette Cuffari, M.Sc. When radiation therapy is used to kill cancerous cells in the body , it is important to measure the dose correctly to avoid unnecessary damage to normal cells in the body. Radiation is not selective to tumor cells and therefore targets any cells that are in the process ...
Why is patient positioning important during radiation treatment?
The exact position of the patient during the radiation treatment is of utmost importance to ensure that the correct dose of radiation is emitted to the intended area of the body. It is common practice for skin to be marked to indicate where the treatment should be focused.
Why do you need a mold for radiation?
Additionally, areas of the body that do not contain tumor cells should be subjected to as little radiation as possible, often necessitating blocks or shields to protect other parts of the body .
Is radiation selective to tumor cells?
Radiation is not selective to tumor cells and therefore targets any cells that are in the process of replication when the therapy is applied. This thereby stresses the importance of administering the correct dose in order to ensure optimal efficiency with minimal side effects. Image Credit: Roman Zaiets / Shutterstock.com.