微劑量學簡介

MICRODOSIMETRY

董傳中(Chuan-Jong Tung)

《中華放射線醫學雜誌》 4卷2期 (1979/06) Pp. 183-188

摘要

游離輻射生物效應的起因，源於細胞內某些重要分子（稱為靶）的吸收能量。看跡象顯示，靶內所發生的極少次碰撞事件，甚至於一次碰撞，所引起的能量轉移即足以使靶受損，導致細胞的死亡。而這些靶分子的體積長度通常向小於微米。因此，輻射粒子在靶區內的能量積沉分布，係決定生物效應的重要因素。由於研究此微觀靶區內之能量分布，使得羅西及其同僚發展出微劑量學的方法。微劑量學的最大用途在於它實際探討影響生物效應之微觀體積內的能量耗損分布，並且幫助瞭解輻射所引起的生物效應發展過程。

並列摘要

The effects of ionizing radiation produce in living matter result from energy transferred to one or more molecules of which cells are made. The size of these molecules (referred to as target) is usually very small, of micrometer dimensions or less. Indications show that individual targets suffer inactivation ＂leading to cell death due to a single energy transfer event or very few events. Consequently, the statistical distribution of energy deposition by charged particles in such targets play an important role in determining the observable biological effect. Consideration of the actual energy losses in the microscopic relevant volumes of cells led Rossi and his co-workers to introduce microdosimetry. The greatest value of microdosimetry is in the fact that it makes possible prediction concerning the .actual energy loss distribution in biologically critical volumes and thereby help in the' identification of mechanisms of radiobiological action.