Background radiation equivalent time small area in India as high as 30 mSv (3 rem). Using the 2.4 mSv value each BRET unit equals 6.6 μSv. BRET values for diagnostic radiography procedures range from 2 BRET for a dental x-ray to around 400 for a barium enema study. Background radiation equivalent time Background Radiation Equivalent Time, or BRET, is a unit of measurement of ionizing radiation dosage. One BRET is the equivalent of one day worth of average human exposure to background radiation. The unit is also referred to as BERT (Background Equivalent Radiation Time). BRET units are used as a measure of low
Biological effects of radiation on the epigenome the normal development of the brain. DNA methylation influences tissue responses to ionizing radiation. Modulation of methylation in the gene MGMT or in transposable elements such as LINE1 could be used to alter tissue responses to ionizing radiation and potentially opening new areas for cancer treatment. MGMT serves as a prognostic marker in glioblastoma. Hypermethylation of MGMT is associated with the regression of tumors. Hypermethylation of MGMT silences its transcription inhibiting alkylating agents in tumor killing cells. Studies have shown patients who received radiotherapy, but no chemotherapy after tumor extraction, had an improved response to radiotherapy due to the methylation