Related Experiment Video
Updated: May 8, 2026
03:07
Single-Port Robotic-assisted Transaxillary Breast-conserving Surgery: A Prospective, Single-arm, Non-randomized Phase IIa Clinical Trial
Published on: August 19, 2025
Normal tissue complication probability (NTCP) parameters for breast fibrosis: pooled results from two randomised
Mukesh B Mukesh1, Emma Harris, Sandra Collette
1Oncology Centre, Cambridge University Hospitals NHS Foundation Trust, UK.
Summary
Radiation dose, not volume, is key for breast fibrosis after radiotherapy. This study analyzed 5856 patients, finding maximum dose is the most important factor influencing fibrosis risk.
Area of Science:
- Radiation Oncology
- Medical Physics
- Oncology
Background:
- The relationship between radiation dose and breast tissue toxicity, specifically fibrosis, remains unclear.
- Understanding dose-volume effects is crucial for optimizing radiotherapy planning and minimizing side effects.
Purpose of the Study:
- To estimate Normal Tissue Complication Probability (NTCP) parameters for breast fibrosis following external beam radiotherapy.
- To identify key dosimetric parameters influencing the development of breast fibrosis.
Main Methods:
- Pooled data from 5856 patients across two clinical trials (whole breast irradiation with or without boost).
- Utilized a two-compartment dose-volume histogram model, separating boost and remaining breast volumes.
- Validated model predictions using data from the START-pilot trial (n=1410).
Main Results:
- Moderate-to-severe breast fibrosis observed in 26.8% (5 years) and 20.7% (10 years) of patients.
- Identified optimal NTCP parameters for Niemierko and Lyman Kutcher Burman models.
- Predicted fibrosis rates closely matched observed rates in the START-pilot trial, confirming model accuracy.
Conclusions:
- Maximum radiation dose, rather than volume parameters, is the primary determinant of breast fibrosis.
- The small volume parameter 'n' suggests breast tissue may not behave as a purely parallel organ, potentially due to limitations in current fibrosis assessment.
- Findings emphasize the importance of dose constraints in radiotherapy planning to mitigate fibrosis risk.