Performance of a hybrid Monte Carlo‐Pencil Beam dose algorithm for proton therapy inverse planning

Montero, Aldemar; Souris, Kevin; Sánchez-Parcerisa, Daniel; Sterpin, Edmond; Lee, John A.

doi:10.1002/mp.12688

Cited by 15 publications

(12 citation statements)

References 33 publications

(84 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For this case, we generated a new plan using the MCsquare-based optimizer, MIROpt. 33 From the DVH in the Fig. 7, it can be observed that the dose recalculated by MCsquare reflects significant degradation of D95 by 6.8% and of the HI index by 6.0% compared to what the ADC would indicate.…”

Section: Discussionmentioning

confidence: 93%

“…. For this case, we generated a new plan using the MCsquare‐based optimizer, MIROpt . From the DVH in the Fig.…”

Section: Discussionmentioning

confidence: 99%

“…An in‐house and open‐source fast MC code, MCsquare, which is optimized and dedicated to pencil beam scanning (PBS) proton therapy simulations in voxelized geometries, such as a CT image, was employed. An open‐source collaboration, OpenReggui, has integrated both MCsquare‐based dose calculation and the planning tool MIROpt to make fast MC‐based post‐planning evaluation and planning available to community hospitals, and to provide an ideal tool for collaboration among institutions or potentially for centralized auditing IROC/NRG . MCsquare was previously benchmarked with Geant4 simulations and validated by measurements for simple homogeneous and heterogeneous phantom geometries …”

Section: Introductionmentioning

confidence: 99%

“…However, the fast MC codes are confined to a few research institutions and limited to post‐planning dose calculation. The MC‐based plan optimization, such as that in Raystation, would be essential to remedy dose calculation issues.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Validation and application of a fast Monte Carlo algorithm for assessing the clinical impact of approximations in analytical dose calculations for pencil beam scanning proton therapy

Huang

Souris

et al. 2018

Medical Physics

Self Cite

View full text Add to dashboard Cite

Purpose Monte Carlo (MC) dose calculation is generally superior to analytical dose calculation (ADC) used in commercial TPS to model the dose distribution especially for heterogeneous sites, such as lung and head/neck patients. The purpose of this study was to provide a validated, fast, and open‐source MC code, MCsquare, to assess the impact of approximations in ADC on clinical pencil beam scanning (PBS) plans covering various sites. Methods First, MCsquare was validated using tissue‐mimicking IROC lung phantom measurements as well as benchmarked with the general purpose Monte Carlo TOPAS for patient dose calculation. Then a comparative analysis between MCsquare and ADC was performed for a total of 50 patients with 10 patients per site (including liver, pelvis, brain, head‐and‐neck, and lung). Differences among TOPAS, MCsquare, and ADC were evaluated using four dosimetric indices based on the dose‐volume histogram (target Dmean, D95, homogeneity index, V95), a 3D gamma index analysis (using 3%/3 mm criteria), and estimations of tumor control probability (TCP). Results Comparison between MCsquare and TOPAS showed less than 1.8% difference for all of the dosimetric indices/TCP values and resulted in a 3D gamma index passing rate for voxels within the target in excess of 99%. When comparing ADC and MCsquare, the variances of all the indices were found to increase as the degree of tissue heterogeneity increased. In the case of lung, the D95s for ADC were found to differ by as much as 6.5% from the corresponding MCsquare statistic. The median gamma index passing rate for voxels within the target volume decreased from 99.3% for liver to 75.8% for lung. Resulting TCP differences can be large for lung (≤10.5%) and head‐and‐neck (≤6.2%), while smaller for brain, pelvis and liver (≤1.5%). Conclusions Given the differences found in the analysis, accurate dose calculation algorithms such as Monte Carlo simulations are needed for proton therapy, especially for disease sites with high heterogeneity, such as head‐and‐neck and lung. The establishment of MCsquare can facilitate patient plan reviews at any institution and can potentially provide unbiased comparison in clinical trials given its accuracy, speed and open‐source availability.

show abstract

Section: Discussionmentioning

confidence: 93%

“…. For this case, we generated a new plan using the MCsquare‐based optimizer, MIROpt . From the DVH in the Fig.…”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Validation and application of a fast Monte Carlo algorithm for assessing the clinical impact of approximations in analytical dose calculations for pencil beam scanning proton therapy

Huang

Souris

et al. 2018

Medical Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…The robustness test presented in this paper is applied to a patient case in order to illustrate the feasibility of this concept. The MIROpt 4D robust optimizer, developed in house and based on MCsquare dose calculation, was employed to generate a treatment plan for a lung tumor patient. A robust plan was optimized on the clinical target volume (CTV) based on the 4DCT series composed of 10 CT phases.…”

Section: Methodsmentioning

confidence: 99%

Technical Note: Monte Carlo methods to comprehensively evaluate the robustness of 4D treatments in proton therapy

et al. 2019

Self Cite

View full text Add to dashboard Cite

Introduction Proton therapy is very sensitive to treatment uncertainties. These uncertainties can induce proton range variations and may lead to severe dose distortions. However, most commercial tools only offer a limited integration of these uncertainties during treatment planning. In order to verify the robustness of a treatment plan, this study aims at developing a comprehensive Monte Carlo simulation of the treatment delivery, including the simulation of setup and range errors, variation of the breathing motion, and interplay effect. Method Most clinically relevant uncertainties have been modeled and implemented in the fast Monte Carlo dose engine MCsquare. Especially, variation of the breathing motion is taken into account by deforming the initial Four‐dimensional computed tomography (4DCT) series and generating multiple new 4DCT series with scaled motion. Systematic and random errors are randomly sampled, following a Monte Carlo approach, to generate individual erroneous treatment scenarios. The robustness of treatment plans is analyzed and reported with dose‐volume histogram (DVH) bands. The statistical uncertainty coming from the Monte Carlo scenario sampling is studied. Results A validation demonstrated the ability of the motion model to generate new 4DCT series with scaled motion amplitude and improved image quality in comparison to the initial 4DCT. The robustness analysis is applied to a lung tumor treatment. Considering the proposed uncertainty model, the simulation of 300 treatment scenarios was necessary to reach an acceptable level of statistical uncertainty on the DVH band. Conclusion A comprehensive and statistically sound method of treatment plan robustness verification is proposed. The uncertainty model presented in this paper is not specific to protons and can also be applied to photon treatments. Moreover, the generated 4DCT series, with scaled motion, can be imported in commercial TPSs.

show abstract

Teaching treatment planning for protons with educational open‐source software: experience with FoCa and matRad

Sánchez-Parcerisa

Udı́as

2018

J Applied Clin Med Phys

Self Cite

View full text Add to dashboard Cite

Open‐source, MATLAB‐based treatment planning systems FoCa and matRAD were used in a pilot project for training prospective medical physicists and postgraduate physics students in treatment planning and beam modeling techniques for proton therapy. In the four exercises designed, students learnt how proton pencil beams are modeled and how dose is calculated in three‐dimensional voxelized geometries, how pencil beam scanning plans (PBS) are constructed, the rationale behind the choice of spot spacing in patient plans, and the dosimetric differences between photon IMRT and proton PBS plans. Sixty students of two courses participated in the pilot project, with over 90% of satisfactory rating from student surveys. The pilot experience will certainly be continued.

show abstract

Performance of a hybrid Monte Carlo‐Pencil Beam dose algorithm for proton therapy inverse planning

Cited by 15 publications

References 33 publications

Validation and application of a fast Monte Carlo algorithm for assessing the clinical impact of approximations in analytical dose calculations for pencil beam scanning proton therapy

Validation and application of a fast Monte Carlo algorithm for assessing the clinical impact of approximations in analytical dose calculations for pencil beam scanning proton therapy

Technical Note: Monte Carlo methods to comprehensively evaluate the robustness of 4D treatments in proton therapy

Teaching treatment planning for protons with educational open‐source software: experience with FoCa and matRad

Contact Info

Product

Resources

About