Related Experiment Video
Updated: Aug 15, 2026
08:34
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Comparing Different Planning Strategies for Pencil Beam Scanning Carbon Ion Radiotherapy for Stage I Peripheral
Yan Lu1, Jian Chen2, Yinxiangzi Sheng1
1Shanghai Key Laboratory of radiation oncology, Shanghai 201321, China; Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201321, China; Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Shanghai 201321, China.
International Journal of Radiation Oncology, Biology, Physics
|August 13, 2026
Summary
For stage I non-small cell lung cancer (NSCLC) treated with carbon-ion radiotherapy (CIRT), robust optimization (RO) allows smaller margins. Density override (DO) is beneficial for solid tumors, especially with RO.
Area of Science:
- Radiation Oncology
- Medical Physics
- Thoracic Surgery
Background:
- Stage I peripheral non-small cell lung cancer (NSCLC) presents a challenge for radiotherapy planning.
- Pencil beam scanning carbon-ion radiotherapy (CIRT) offers precise dose delivery.
- Optimizing planning strategies is crucial for maximizing efficacy and minimizing toxicity.
Purpose of the Study:
- To determine the optimal planning strategy for CIRT in stage I peripheral NSCLC.
- To evaluate different margin expansion (ME), density override (DO), and robust optimization (RO) techniques.
- To compare treatment outcomes for ground-glass opacity (GGO) and solid lesions.
Main Methods:
- Thirty patients with stage I NSCLC (15 GGO, 15 solid) received CIRT (8 Gy (RBE) x 9 fractions).
- Eight treatment plans were generated per patient using combinations of ME, DO, and RO.
- Target coverage (CTV V95%) and lung dose (MLD, Vx) were assessed under range and setup uncertainties.
Main Results:
- All strategies improved CTV V95% but increased lung dose.
- RO demonstrated significant CTV V95% improvement with moderate MLD increase.
- For GGOs, CTV+RO provided adequate coverage with lowest lung dose; for solid tumors, CTV+RO+DO achieved near-complete coverage with minimal MLD increase.
Conclusions:
- Quantitative data support evidence-based planning for CIRT in stage I NSCLC.
- Without RO, larger margins (CTV+ME) are recommended, with DO beneficial for solid tumors.
- With RO, smaller margins (CTV) are sufficient, and DO remains valuable for solid tumors, especially under uncertainty.
Keywords:
Carbon ion radiotherapydensity overridelung cancermargin expansionplanningrange uncertaintyrobust optimizationsetup uncertainty
