About LET; all are false except (NOT RELATED TO PHARMACOLOGY): (A) Low LET radiations are more lethal, (B) It is the propey of the tissue, (C) Same as relative biological effectiveness, (D) High LET radiations have low oxygen enhancement ratio
Answer is D. LET (linear energy transfer)- it is the amount of energy deposited per unit length. Given as Kev/ micrometre. It is highest for alpha paicle (high LET), low for beta paicles and gamma emissions (Low LET). It is a propey of the radiation. OER (oxygen enhancement ratio )is the ratio of quantity of radiation required to kill tumour cells in the absence of oxygen to the quantity of radiation required to kill same amount of tumour cells in the presence of oxygen. OER is low for high LET radiations (OER= 1) and high for low LET radiations(OER= 2-3).