Virtual Cell (VC) Radiobiology Software User Manual

Tutorial 1.1 Single-dose exposures
How to set up radiation exposure scenarios

A single dose of radiation delivered at a constant dose rate can be setup using several different methods. Multiple exposure scenarios can also be created using a single input file. This tutorial provides several examples of how to setup up one or more single-dose exposure scenarios (or a family of single-dose exposure scenarios).

Instructions: Place the illustrative examples into an ASCII input file (see What is an ASCII file? and How do I Edit ASCII files?) and then use the RIO application, which is typically executed from the command prompt, to convert the input into an ASCII output file (a .radx binary file will also be created but this file can be ignored for now). Compare the processed information in the output file to the desired exposure scenario(s) specified in the input file. Did the input file generated the desired exposure scenarios in the output file?

Example 1 A 20 Gy dose delivered at 100 Gy/h (sd1.inp, sd1.out)

! METHOD 1: Dose and dose rate

RADX: AD=20 ADR=100

Comment: DOX = AD/ADR = 20 Gy/(100 Gy/h) = 0.2 h

Example 2 A 20 Gy dose delivered in 0.2 hour (sd2.inp, sd2.out)

! METHOD 2: Dose and irradiation time

RADX: AD=20 DOX=0.2

Comment: ADR = AD/DOX = 20 Gy/(0.2 h) = 100 Gy/h

Example 3 100 Gy/h for 0.2 hour (sd3.inp, sd3.out)

! METHOD 3: Irradiation time and dose rate

RADX: ADR=100 DOX=0.2

Comment: AD = ADR*DOX = (100 Gy/h)*(0.2 h) = 20 Gy

Example 4 Multiple scenarios specified by different doses and dose rates (sd4.inp, sd4.out)

! Doses of 0 through 10 Gy with increments of 1Gy.

! with dose rates: 0.2, 1.0 and 5.0 Gy/h

RADX: AD=DD1 ADR=DD2

DD1=0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 /

DD2=0.2, 1.0, 5.0 /

Comment: The input file contains (11 doses) * (3 dose rates) = 33 separate exposure scenarios

Example 5 Multiple scenarios specified by different doses and durations of exposure (sd5.inp, sd5.out)

! Doses of 0 through 10 Gy with increments of 1 Gy.

! with irradiation times: 1.0, 2.0 and 5.0 h

RADX: AD=DD1 DOX=DD2

DD1=0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 /

DD2=1.0, 2.0, 5.0 /

Comment: The input file contains (11 doses) * (3 irradiation times) = 33 separate exposure scenarios.

Example 6 Multiple scenarios specified by different dose rates and durations of exposure (sd6.inp, sd6.out)

! Dose rates of 0 through 10Gy/h with increments of 1Gy/h.

! with irradiation times: 0.1, 1.0 and 10.0 h

RADX: ADR=DD1 DOX=DD2

DD1=0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 /

DD2=0.1, 1.0, 10.0 /

Comment: The input file contains (11 irradiation times) * (3 dose rates) = 33 separate exposure scenarios.

Suggested Problems: For all of the sample problems, use RIO to process the input file into an output file. Verify that the RIO application generates the desired exposure scenario. Debug as necessary.

In Example 1.4, could other variable names be substituted for DD1 and DD2?

Debug the linked input file.

Write an input file for an exposure scenario such that a total dose of 50 Gy is delivered uniformly during a period of 10 hours (use the input parameters AD and ADR).

Setup an exposure scenario to irradiation a collection of cells for 0.5 hours at a dose rate of 1 Gy per minute (use input parameters DOX and ADR).

Setup an exposure scenario to deliver a total dose of 10 cGy over 5 hours (use the input parameters AD and DOX).

Setup a single input file to generate two exposure scenarios. The first exposure scenario irradiates a collection of cells for 1 minute at 1,000 Gy/h, and the second exposure scenario irradiates a collection of cells at 1,000 Gy/h for 0.25 h.

Write a single input file to define a family of 5 exposure scenarios: 5 Gy delivered in 10 h, 10 Gy delivered in 20 h, 15 Gy delivered in 30 h, 20 Gy delivered in 40 h, and 25 Gy delivered in 50 h.

School of Health Sciences
Purdue University
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Last updated: 10 June, 2011
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