RADIOBIOLOGY CHEAT
SHEET (WITH EQUATIONS
& FORMULAS)
[Document subtitle]
, 1. Cell Biology & Radiation Basics
1.1 Cell Structure & Sensitivity
Nucleus is the most radiosensitive organelle.
DNA is the critical target → damage leads to mutation, apoptosis, mitotic death.
Chromosomes show dicentrics, rings, acentric fragments after radiation.
1.2 Radiobiological Law
Law of Bergonié & Tribondeau:
Radiosensitivity ↑ when cells are:
Highly mitotic
Undifferentiated
Rapidly dividing
Example: Lymphocytes (very sensitive), neurons (resistant).
1.3 Types of Radiation Damage
Direct action: ionization of DNA directly (important in high-LET).
Indirect action: radiolysis of water → ROS (OH•) → DNA damage (dominant in
low-LET, e.g., X-rays).
2. DNA Damage & Cell Survival
2.1 DNA Damage Types
Base damage
Single-strand breaks (SSBs)
Double-strand breaks (DSBs) → most lethal
Crosslinks (DNA-DNA, DNA-protein)
2.2 Cell Survival Curve
For mammalian cells, the curve follows Linear-Quadratic Model:
2)
𝑆𝐹 = 𝑒 −(𝛼𝐷+𝛽𝐷
α component = single-hit killing (linear)
SHEET (WITH EQUATIONS
& FORMULAS)
[Document subtitle]
, 1. Cell Biology & Radiation Basics
1.1 Cell Structure & Sensitivity
Nucleus is the most radiosensitive organelle.
DNA is the critical target → damage leads to mutation, apoptosis, mitotic death.
Chromosomes show dicentrics, rings, acentric fragments after radiation.
1.2 Radiobiological Law
Law of Bergonié & Tribondeau:
Radiosensitivity ↑ when cells are:
Highly mitotic
Undifferentiated
Rapidly dividing
Example: Lymphocytes (very sensitive), neurons (resistant).
1.3 Types of Radiation Damage
Direct action: ionization of DNA directly (important in high-LET).
Indirect action: radiolysis of water → ROS (OH•) → DNA damage (dominant in
low-LET, e.g., X-rays).
2. DNA Damage & Cell Survival
2.1 DNA Damage Types
Base damage
Single-strand breaks (SSBs)
Double-strand breaks (DSBs) → most lethal
Crosslinks (DNA-DNA, DNA-protein)
2.2 Cell Survival Curve
For mammalian cells, the curve follows Linear-Quadratic Model:
2)
𝑆𝐹 = 𝑒 −(𝛼𝐷+𝛽𝐷
α component = single-hit killing (linear)
