A cell survival curve is a curve used in
radiobiology. It depicts the relationship between the fraction of
cells
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...
retaining their reproductive integrity and the
absorbed dose
Absorbed dose is a dose quantity which is the measure of the energy deposited in matter by ionizing radiation per unit mass. Absorbed dose is used in the calculation of dose uptake in living tissue in both radiation protection (reduction of harmf ...
of radiation. Conventionally, the surviving fraction is depicted on a
logarithmic scale
A logarithmic scale (or log scale) is a way of displaying numerical data over a very wide range of values in a compact way—typically the largest numbers in the data are hundreds or even thousands of times larger than the smallest numbers. Such a ...
, and is plotted on the y-axis against dose on the x-axis.
The
linear quadratic model is now most often used to describe the cell survival curve, assuming that there are two mechanisms to cell death by radiation: A single lethal event or an accumulation of harmful but non-lethal events. Cell survival fractions are exponential functions with a dose-dependent term in the exponent due to the
Poisson statistics
In probability theory and statistics, the Poisson distribution is a discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time or space if these events occur with a known co ...
underlying the
stochastic process
In probability theory and related fields, a stochastic () or random process is a mathematical object usually defined as a family of random variables. Stochastic processes are widely used as mathematical models of systems and phenomena that appea ...
. Whereas single lethal events lead to an exponent that is linearly related to dose, the survival fraction function for a two-stage mechanism carries an exponent proportional to the square of dose. The coefficients must be inferred from measured data, such as the Hiroshima Leukemia data. With higher orders being of lesser importance and the total survival fraction being the product of the two functions, the model is aptly called linear-quadratic.
See also
*
Dose fractionation Dose fractionation effects are utilised in the treatment of cancer with radiation therapy. When the total dose of radiation is divided into several, smaller doses over a period of several days, there are fewer toxic effects on healthy cells. This ma ...
*
Dose–response relationship
*
Chronic radiation syndrome
Chronic radiation syndrome (CRS), or chronic radiation enteritis, is a constellation of health effects of radiation that occur after months or years of chronic exposure to high amounts of radiation. Chronic radiation syndrome develops with a speed ...
External links
*
Curves
Radiobiology
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