Radiation Therapy BED Visualizer
A New Visual Tool for Patients and Clinicians
TL;DR
Radiation therapy regimens look different on paper, but their biological effects on cancer and normal tissues can be hard to compare. The Radiation Therapy BED Visualizer turns these complex radiobiology concepts into simple visuals. You can explore how different fractionation schedules affect tumor and OAR responses, select multiple OARs at once, compare up to 4 regimens, and instantly see which schedules offer stronger tumor control and which are gentler on normal tissues. This tool brings clarity to conversations that were previously abstract and improves shared decision-making in the clinic.
Introduction
Radiation therapy often feels technical and abstract to patients. Even clinicians can find it difficult to explain why two treatment schedules with very different doses and fraction numbers produce similar tumor control or very different effects on surrounding tissue.
The Radiation Therapy BED Visualizer was created to solve that problem. It uses simple visuals to make the biology of radiation more intuitive. Instead of looking at formulas and numbers, users see what really matters: how much biological effect a treatment delivers to a tumor and to each selected organ at risk.
APP LINK: https://radiation-dose-visualizer-8156b2bf.base44.app
The app is built around Biologically Effective Dose (BED), one of the most widely used tools for comparing radiation regimens. BED helps clinicians understand how fraction size, number of treatments, and tissue sensitivity influence both tumor control and potential side effects. The Visualizer turns this into a clear and approachable experience.
Key Features of the BED Visualizer
Select Your Tumor Type
Users begin by selecting a tumor type such as Prostate Cancer, Breast Cancer, or Lung Cancer.
This automatically sets the biologically appropriate alpha beta ratio (α/β) for the tumor.
Changing the tumor type now clears any previously selected OARs. This ensures that all biological calculations remain valid and prevents accidental mixing of mismatched settings.
Select Multiple Organs at Risk (OARs)
This feature now allows users to select up to four organs at risk that are relevant to the treatment site. Examples include:
Rectum
Bladder
Lung
Skin
Bowel
Each selected OAR appears with its own normal tissue cup for every treatment scheme. This makes it possible to compare how the same schedule affects different structures.
The app uses QUANTEC-based dose tolerance thresholds, expressed in BED, to indicate when a particular OAR may be approaching or exceeding a widely accepted risk boundary.
Add and Compare Treatment Schedules
Users can create up to four treatment schemes for side-by-side comparison.
Each regimen can be customized with:
Total dose in Gy
Dose per treatment
Number of fractions
This allows clinicians to visually compare:
Conventional regimens
Moderate hypofractionation
Ultra-hypofractionation or SBRT
Boost plans or mixed schedules
All schemes use the chosen tumor α/β and all selected OAR α/β values for accurate comparisons.
Tumor Effect Cup (Orange)
Each regimen displays a bright orange Tumor Cup that shows the biological effect on cancer.
More fill means higher tumor-killing effect.
Tumor BED is displayed clearly for transparency.
This cup helps patients instantly understand the difference between regimens like 70 Gy in 28 fractions versus 36.25 Gy in 5 SBRT fractions even though both may produce similar tumor control.
OAR Cups for Each Selected Organ (Blue)
Every selected OAR appears as its own cup beneath every scheme.
For example, if bladder and rectum are selected, each scheme will show two blue cups.
More fill means higher biological stress on that organ.
The yellow QUANTEC limit line is drawn across the cup.
The region above the line is softly shaded to represent increasing risk.
This setup allows clinicians to show why two regimens with similar tumor BED may have completely different normal tissue consequences.
QUANTEC Safety Limit Line
Across each OAR cup is a yellow line labeled with the OAR-specific QUANTEC limit expressed in BED.
The app provides clear visual signals:
Green: Below the limit and considered safe
Yellow: Near the limit
Red: Above the limit
The red gradient glow around the cup and line helps the user understand the biological implications at a glance.
Safety Badges for Instant Interpretation
Under each OAR cup, users see one of three badges:
Safe (green)
Near Limit (yellow)
Above Limit (red)
These badges require no technical background and allow patients to grasp safety differences immediately.
“What This Means” Summary Section
Each scheme includes a patient-friendly text box summarizing:
The tumor effect
The normal tissue effect
Why the chosen fractionation behaves the way it does biologically
This allows clinicians to focus the conversation while the app handles the explanation.
QUANTEC Education Section
Below all visualizations is an expandable education section that includes:
What QUANTEC is
What the yellow line means
Why the limit matters
What it means when a schedule goes above the limit
A final key takeaway
This transforms the tool into not just a calculator but a teaching platform.
Comparison Highlight Strip
At the top of the schemes, the app automatically identifies:
Largest Tumor Punch
Least Normal Tissue Impact
Shortest Treatment Course
Patients can quickly see which regimen is strongest for cancer, which is gentlest on normal tissues, and which gets them done fastest.
Animation Mode (Play Button)
The play button animates the treatment course from the first fraction to the last.
Users watch the tumor and OAR cups fill gradually, which helps illustrate:
Why smaller fractions spare normal tissue
Why larger fractions produce stronger instantaneous biological effects
Why SBRT requires precise dose shaping
This single feature transforms abstract radiobiology into something completely intuitive.
Multiple View Options
The app supports:
Swipe Mode for smartphones
2-Up Mode for side-by-side comparisons on desktop
The prior grid view was removed to keep the experience clean and focused.
Examples of Clinical Use
Prostate Cancer
Clinicians can visually compare:
78 Gy in 39 fractions
70 Gy in 28 fractions
60 Gy in 20 fractions
36.25 Gy in 5 fractions (SBRT)
Users can simultaneously display both rectum and bladder cups.
This makes it clear that some regimens increase rectal stress, others increase bladder stress, and SBRT can exceed QUANTEC limits even when clinically safe because high doses are delivered to very small volumes.
Breast Cancer
Users can compare:
50 Gy in 25 fractions
42.5 Gy in 16 fractions
26 Gy in 5 fractions
With OARs such as the skin and chest wall, the app shows how hypofractionation maintains tumor control while being biologically gentle to most normal tissues.
This turns abstract concepts into a visual story that patients immediately understand.
Conclusion
The Radiation Therapy BED Visualizer brings clarity to conversations about radiation fractionation. By transforming complex radiobiology into a simple and intuitive visual format, the app helps clinicians communicate more effectively and helps patients engage more confidently in their treatment decisions.
If you have suggestions for improvements or find bugs, please don't hesitate to contact me. The coding app (Base44) is not very sophisticated and may not offer the flexibility needed to implement all improvements.