Related Experiment Video
Updated: Jun 3, 2026
08:34
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Evaluation of flexible and rigid (class solution) radiation therapy conformal prostate planning protocols
Natalie Coburn1, Rachael Beldham-Collins, Jelene Westling
1Radiation Oncology Network, Nepean Cancer Care Centre, University of Sydney, Sydney, New South Wales, Australia. natalie.coburn@swahs.health.nsw.gov.au
Summary
Flexible radiotherapy protocols for prostate cancer planning reduce plan modifications by 53%. While taking longer, flexible protocols may improve plan quality, suggesting a need for further study in radiation therapy planning.
Area of Science:
- Radiation Oncology
- Medical Physics
Background:
- Radiotherapy protocols are classified as rigid or flexible.
- Formal evaluation of these protocol types is lacking in scientific literature.
Purpose of the Study:
- To evaluate the efficiency of rigid versus flexible prostate planning protocols.
- To assess the impact of protocol type on the quality and modification rates of 3D conformal prostate plans.
Main Methods:
- Twenty prostate cancer patients' plans were created using a rigid and a flexible protocol on the Phillips Pinnacle treatment planning system.
- Plans were created by radiation therapists with varying experience levels (<2, 2-5, >5 years).
- Plan quality was assessed using critical organ doses, confirmation numbers, and conformity index, classifying plans as acceptable or not.
Main Results:
- Flexible protocols resulted in plans 53% less likely to require modification (OR 0.47).
- Planners with >5 years of experience were 78% more likely to produce plans needing modification (OR 1.78).
- Flexible protocol plans took significantly longer (112 min) than rigid protocol plans (68 min).
Conclusions:
- Flexible protocols show promise in reducing plan modifications for prostate radiotherapy.
- Experience level may influence plan modification rates, with more experienced planners potentially needing more modifications under certain conditions.
- A hybrid approach, starting with rigid constraints and allowing flexibility if needed, is proposed to optimize radiotherapy plan quality.
