radiation_bed_calculator: Radiation Biologically Effective Dose (BED) Calculator

In cliot: Clinical Indices and Outcomes Tools

Radiation Biologically Effective Dose (BED) Calculator

Description

Calculates the Biologically Effective Dose (BED) and the Equivalent Dose in 2 Gy fractions (EQD2) using the linear-quadratic model. This allows for the comparison of different radiation fractionation schedules by normalizing them to a biologically equivalent dose based on tissue sensitivity (alpha/beta ratio).

Usage

radiation_bed_calculator(dose_per_fraction_gy, number_of_fractions, alpha_beta_ratio)

Arguments

dose_per_fraction_gy	Numeric. The radiation dose delivered per fraction in Gray (Gy).
number_of_fractions	Numeric. The total number of fractions in the treatment schedule.
alpha_beta_ratio	Numeric. The alpha/beta ratio for the specific tissue or tumor type. Common values: 10 Gy for early-responding tissues and most tumors. 3 Gy for late-responding tissues (e.g., spinal cord, lung). 1.5-3 Gy for prostate cancer.

Value

A list containing:

BED_Gy	The Biologically Effective Dose.
EQD2_Gy	The equivalent total dose if delivered in 2 Gy fractions.
Total_Physical_Dose_Gy	The total physical dose delivered.

References

Fowler JF. The linear-quadratic formula and progress in fractionated radiotherapy. Br J Radiol. 1989;62(740):679-694. doi:10.1259/0007-1285-62-740-679

Examples

# Example 1: Standard Fractionation (Tumor Control)
# 2 Gy x 30 fractions, a/b = 10
# Total = 60 Gy. BED = 60 * (1 + 2/10) = 72 Gy10.
radiation_bed_calculator(2, 30, 10)

# Example 2: SBRT (Tumor Control)
# 20 Gy x 3 fractions, a/b = 10
# Total = 60 Gy. BED = 60 * (1 + 20/10) = 180 Gy10.
radiation_bed_calculator(20, 3, 10)

# Example 3: Late Toxicity Check (Spinal Cord)
# 3 Gy x 10 fractions (Palliative), a/b = 3
# Total = 30 Gy. BED = 30 * (1 + 3/3) = 60 Gy3.
radiation_bed_calculator(3, 10, 3)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.