cGy

cGy stands for centigray, a unit used to measure the dose of radiation absorbed by body tissue during radiotherapy. One centigray equals one-hundredth of a gray (Gy), and 100 cGy equals 1 Gy. In everyday clinical language, 1 cGy is equivalent to 1 rad, the older radiation unit some patients may still see referenced.

Origin

The gray was adopted in 1975 by the International Commission on Radiation Units and Measurements and named after British physicist Louis Harold Gray, a pioneer in radiobiology. The centigray (cGy) was introduced as a practical sub-unit because it matches the older rad unit one-to-one, easing the transition for clinicians.

Significance in Asbestos Context

Patients with mesothelioma or asbestos-related lung cancer often receive radiation therapy, and their treatment records will list doses in cGy. For pleural mesothelioma, typical regimens may include hemithoracic radiation totaling around 4,500–5,400 cGy in daily fractions of about 180–200 cGy, while palliative radiation for chest pain or to prevent tumor seeding at biopsy sites uses lower totals. Understanding cGy helps patients follow their treatment plan, recognize cumulative dose limits to nearby organs (heart, lungs, spinal cord), and read the radiation oncology notes that often become important evidence of treatment burden in a legal claim.

Example Sentence

Her radiation oncologist prescribed 5,000 cGy delivered in 25 daily fractions to the left hemithorax following extrapleural pneumonectomy.

Related Terms

Gray (Gy), Fractionation, Radiotherapy, IMRT, Palliative Radiation, Hemithoracic Radiation

Notes

• Ask your radiation oncologist for a written summary of the total prescribed dose in cGy, the number of fractions, and the target area. This becomes part of your treatment record and may support damages in a legal claim.
• Request that organ-at-risk doses (to lung, heart, esophagus, spinal cord) be documented; cumulative cGy to these organs affects what treatments you can safely receive later.
• If you see 'rad' in older records, remember 1 rad = 1 cGy, so doses can be compared directly.
• Keep copies of radiation planning summaries and daily treatment records; these document the intensity of care you required because of an asbestos-caused cancer.