Radiation Linear Quadratic Model

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What is the mean lethal dose, the quantity of dose that delivers one inactivating event per cell?

D0 (correct)

α

β

S

Which phase of interphase involves the duplication of DNA where 4 chromatids are joined at the centromere?

Mitosis

S (correct)

G2

G1

What is the significance of early responders having a higher α/β ratio?

Beta dominates at lower doses

Alpha and beta components are irrelevant

Alpha and beta components are equal

Alpha outweighs beta at lower doses (correct)

Which type of aberration occurs when radiation damage happens after DNA replication, affecting only one daughter cell at the next division?

Chromatid aberrations Signup and view all the answers

Where are the genes housed in a linear sequence, and if in the wrong order, can change their function?

Chromosomes Signup and view all the answers

What is the main consideration in determining the treatment plan using the Linear Quadratic model?

Early vs. late effects and tumor control Signup and view all the answers

Which component of the Linear Quadratic model is determined by the beta value?

Quadratic component Signup and view all the answers

What is a limitation of the linear curve in the Linear Quadratic model?

Addresses straight line portion only, does not tell exact shape of initial shoulder Signup and view all the answers

What do smaller alpha/beta ratios (small alpha component, beta has more influence on lower dose) primarily affect?

Late reacting tissues, e.g. spinal cord and potentially prostate cancer Signup and view all the answers

What characteristic indicates a very high Linear Energy Transfer (LET) in the Linear Quadratic model?

Straightened out curve Signup and view all the answers

Which type of scatter involves high-energy scatter with reduced energy, but still free to interact?

Compton scatter Signup and view all the answers

What is the main effect of radiation interaction in the cell?

Mainly affects biologic macromolecules Signup and view all the answers

What is the result of translocation as an aberration due to radiation exposure?

Creation of dicentric or acentric fragments Signup and view all the answers

What is the characteristic of indirect ionizing radiation?

Causes released energetic charged particles to ionize Signup and view all the answers

What is the main purpose of dose estimation using lymphocyte aberrations?

To compare aberrations to standards for assessment of radiation exposure Signup and view all the answers

What characteristic affects the shape of the cell survival curve in the context of linear energy transfer (LET)?

Low LET indicating tissue repair Signup and view all the answers

What does the ALARA principle aim to balance in the context of radiation exposure?

Benefits of radiation use, likelihood of harm, and cost of exposure minimization Signup and view all the answers

What is the significance of the plating efficiency in the context of estimating cell survival?

Ratio of counted colonies to seeded cells, used to estimate cell survival Signup and view all the answers

What is the primary assumption of the multi-target multi-hit model for cell death?

Cell death requires multiple hits to critical targets Signup and view all the answers

Which characteristic determines how radiosensitive a cell is in the context of radiotherapy?

Extrapolation number Signup and view all the answers