Convert centigray [cGy] to hectogray [hGy] Online | Free radiation-absorbed-dose Converter

Centigray [cGy]: A Practical Unit in Radiation Therapy

The centigray (cGy) is a unit of absorbed radiation dose equal to 0.01 grays (Gy), or one-hundredth of a gray. It is widely used in clinical settings, especially in radiation therapy, where doses need to be both precise and clinically meaningful. One centigray equals 10 milligrays (mGy), making it a convenient unit for prescribing and documenting treatment doses.

In cancer treatment, therapeutic radiation is typically delivered in fractions, with each session often delivering 180–200 cGy (or 1.8–2.0 Gy) to the target area. Using centigrays allows healthcare professionals to express these fractions in whole numbers, simplifying treatment planning and communication. For example, a full course of radiation therapy might involve a total dose of 6000 cGy over several weeks.

Outside of therapy, the cGy is less commonly used, but it remains important in any context where mid-level radiation doses are applied or studied. Its use bridges the gap between small exposures (measured in mGy or µGy) and large, high-dose applications (measured in Gy), making the centigray a key unit in applied radiation science.

Hectogray [hGy]: Measuring Extremely High Radiation Doses

The hectogray (hGy) is a unit of absorbed radiation dose equal to 100 grays (Gy). Since 1 gray corresponds to the absorption of 1 joule of ionizing radiation energy per kilogram of matter, a hectogray represents an extremely large energy dose—100 joules per kilogram. This unit is far above the levels used in medical or environmental contexts.

In radiation therapy, for example, cancer patients typically receive total doses of 60–70 Gy, delivered in small daily fractions. A dose of 100 Gy (or 1 hGy) to the human body would cause severe, often fatal radiation damage, and is not survivable if delivered systemically. Therefore, the hectogray is not used in clinical medicine.

However, the hectogray may be relevant in specialized industrial applications such as:

• 
  

  Radiation sterilization of medical equipment and food, where extremely high doses are used to eliminate all biological contaminants.

  
  
• 
  

  Radiation hardness testing of materials and electronics, particularly for aerospace or nuclear environments.

  
  
• 
  

  Experimental radiobiology, where specific tissues or small organisms are exposed to very high doses to study extreme effects.

  
  

Although rarely used in everyday practice, the hectogray is an important unit in high-dose radiation science and engineering, where understanding material and biological responses to extreme exposure is critical.