BED Calculator

Calculate Biologically Effective Dose (BED) and EQD2 for radiotherapy treatment planning

Calculate BED and EQD2

Select tissue type or use custom α/β ratio

Duration affects the calculation formula

Sum of all doses received

Dose received during single irradiation

Calculation Results

0.0
BED (Gy)
0.0
EQD₂ (Gy)
0
Fractions

Formula used: BED = Total dose × (1 + (Fraction dose / α/β))

EQD₂ Formula: EQD₂ = Total dose × ((Fraction dose + α/β) / (2 + α/β))

Parameters: Total: 0 Gy, Fraction: 0 Gy, α/β: 10

Medical Disclaimer

This calculator is for educational purposes only. Results should be verified by qualified medical professionals before clinical use. Always consult with radiation oncologists for treatment planning decisions.

Clinical Interpretation

Example Calculation

Prostate Cancer Treatment

Total dose: 60 Gy

Dose per fraction: 2 Gy

Tissue type: Late reacting (α/β = 3)

Duration: Standard fractionation (< few minutes)

Calculation

BED = 60 × (1 + (2 / 3))

BED = 60 × (1 + 0.67)

BED = 100 Gy

EQD₂ = 60 × ((2 + 3) / (2 + 3)) = 60 Gy

Common α/β Ratios

Early reacting tissue10
Late reacting tissue3
CNS/Kidneys2
Prostate1.5-3
Melanoma0.6

Radiotherapy Guidelines

Higher α/β means more sensitive to fraction size

BED helps compare different fractionation schedules

EQD₂ standardizes dose reporting

Consider different α/β for tumor vs normal tissue

Understanding BED and EQD2

What is BED?

Biologically Effective Dose (BED) is a way to compare the biological effect of different radiotherapy fractionation schedules. It accounts for both the total dose and the dose per fraction, considering tissue radiosensitivity.

Clinical Applications

  • Compare different fractionation schemes
  • Plan hypofractionated treatments
  • Assess treatment tolerability
  • Research dose escalation studies

Formula Explanation

BED = D × (1 + d/αβ)

For standard delivery

BED = D × (1 + (g×d)/αβ)

For prolonged delivery

  • D: Total dose (Gy)
  • d: Dose per fraction (Gy)
  • α/β: Tissue radiosensitivity ratio
  • g: Dose rate factor (<1 for repair)

Note: EQD₂ normalizes treatments to 2 Gy fractions for easier comparison