Introducing a probabilistic definition of the target in a robust treatment planning framework
| Autor: | John Aldo Lee, Edmond Sterpin, Ana Maria Barragan Montero, G. Buti, Kevin Souris |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Mathematical optimization
Technology minimax Computer science robust optimization THERAPY Standard deviation probabilistic Reduction (complexity) Probabilistic method Engineering worst-case Proton Therapy proton therapy Humans Radiology Nuclear Medicine and imaging stochastic OPTIMIZATION Engineering Biomedical RANGE UNCERTAINTIES Science & Technology Radiological and Ultrasound Technology Radiotherapy Planning Computer-Assisted Radiology Nuclear Medicine & Medical Imaging Probabilistic logic Uncertainty Robust optimization Radiotherapy Dosage Minimax Weighting VOLUME target definition CTD Radiotherapy Intensity-Modulated Life Sciences & Biomedicine Algorithms |
| Popis: | The 'clinical target distribution' (CTD) has recently been introduced as a promising alternative to the binary clinical target volume (CTV). However, a comprehensive study that considers the CTD, together with geometric treatment uncertainties, was lacking. Because the CTD is inherently a probabilistic concept, this study proposes a fully probabilistic approach that integrates the CTD directly in a robust treatment planning framework. First, the CTD is derived from a reported microscopic tumor infiltration model such that it explicitly features the probability of tumor cell presence in its target definition. Second, two probabilistic robust optimization methods are proposed that evaluate CTD coverage under uncertainty. The first method minimizes the expected-value (EV) over the uncertainty scenarios and the second method minimizes the sum of the expected value and standard deviation (EV-SD), thereby penalizing the spread of the objectives from the mean. Both EV and EV-SD methods introduce the CTD in the objective function by using weighting factors that represent the probability of tumor presence. The probabilistic methods are compared to a conventional worst-case approach that uses the CTV in a worst-case optimization algorithm. To evaluate the treatment plans, a scenario-based evaluation strategy is implemented that combines the effects of microscopic tumor infiltrations with the other geometric uncertainties. The methods are tested for five lung tumor patients, treated with intensity-modulated proton therapy. The results indicate that for the studied patient cases, the probabilistic methods favor the reduction of the esophagus dose but compensate by increasing the high-dose region in a low conflicting organ such as the lung. These results show that a fully probabilistic approach has the potential to obtain clinical benefits when tumor infiltration uncertainties are taken into account directly in the treatment planning process. ispartof: PHYSICS IN MEDICINE AND BIOLOGY vol:66 issue:15 ispartof: location:England status: published |
| Databáze: | OpenAIRE |
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