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Ventura T, Rocha H, da Costa Ferreira B, Dias J, do Carmo Lopes M. Comparison of non-coplanar optimization of static beams and arc trajectories for intensity-modulated treatments of meningioma cases. Phys Eng Sci Med 2021; 44:1273-1283. [PMID: 34618329 PMCID: PMC8668856 DOI: 10.1007/s13246-021-01061-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 09/24/2021] [Indexed: 11/30/2022]
Abstract
Two methods for non-coplanar beam direction optimization, one for static beams and another for arc trajectories, were proposed for intracranial tumours. The results of the beam angle optimizations were compared with the beam directions used in the clinical plans. Ten meningioma cases already treated were selected for this retrospective planning study. Algorithms for non-coplanar beam angle optimization (BAO) and arc trajectory optimization (ATO) were used to generate the corresponding plans. A plan quality score, calculated by a graphical method for plan assessment and comparison, was used to guide the beam angle optimization process. For each patient, the clinical plans (CLIN), created with the static beam orientations used for treatment, and coplanar VMAT approximated plans (VMAT) were also generated. To make fair plan comparisons, all plan optimizations were performed in an automated multicriteria calculation engine and the dosimetric plan quality was assessed. BAO and ATO plans presented, on average, moderate global plan score improvements over VMAT and CLIN plans. Nevertheless, while BAO and CLIN plans assured a more efficient OARs sparing, the ATO and VMAT plans presented a higher coverage and conformity of the PTV. Globally, all plans presented high-quality dose distributions. No statistically significant quality differences were found, on average, between BAO, ATO and CLIN plans. However, automated plan solution optimizations (BAO or ATO) may improve plan generation efficiency and standardization. In some individual patients, plan quality improvements were achieved with ATO plans, demonstrating the possible benefits of this automated optimized delivery technique.
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Affiliation(s)
- Tiago Ventura
- Physics Department of University of Aveiro, Aveiro, Portugal.
- Medical Physics Department of the Portuguese Oncology Institute of Coimbra Francisco Gentil, EPE, Coimbra, Portugal.
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal.
| | - Humberto Rocha
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal
- Economy Faculty of University of Coimbra and Centre for Business and Economics Research, Coimbra, Portugal
| | - Brigida da Costa Ferreira
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
- I3N Physics Department of University of Aveiro, Aveiro, Portugal
| | - Joana Dias
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal
- Economy Faculty of University of Coimbra and Centre for Business and Economics Research, Coimbra, Portugal
| | - Maria do Carmo Lopes
- Medical Physics Department of the Portuguese Oncology Institute of Coimbra Francisco Gentil, EPE, Coimbra, Portugal
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal
- I3N Physics Department of University of Aveiro, Aveiro, Portugal
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Sadeghnejad-Barkousaraie A, Bohara G, Jiang S, Nguyen D. A reinforcement learning application of a guided Monte Carlo Tree Search algorithm for beam orientation selection in radiation therapy. MACHINE LEARNING: SCIENCE AND TECHNOLOGY 2021; 2. [DOI: 10.1088/2632-2153/abe528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract
Current beam orientation optimization algorithms for radiotherapy, such as column generation (CG), are typically heuristic or greedy in nature because of the size of the combinatorial problem, which leads to suboptimal solutions. We propose a reinforcement learning strategy using a Monte Carlo Tree Search (MCTS) that can find a better beam orientation set in less time than CG. We utilize a reinforcement learning structure involving a supervised learning network to guide the MCTS and to explore the decision space of beam orientation selection problems. We previously trained a deep neural network (DNN) that takes in the patient anatomy, organ weights, and current beams, then approximates beam fitness values to indicate the next best beam to add. Here, we use this DNN to probabilistically guide the traversal of the branches of the Monte Carlo decision tree to add a new beam to the plan. To assess the feasibility of the algorithm, we used a test set of 13 prostate cancer patients, distinct from the 57 patients originally used to train and validate the DNN, to solve five-beam plans. To show the strength of the guided MCTS (GTS) compared to other search methods, we also provided the performances of Guided Search, Uniform Tree Search and Random Search algorithms. On average, GTS outperformed all the other methods. It found a better solution than CG in 237 s on average, compared to 360 s for CG, and outperformed all other methods in finding a solution with a lower objective function value in less than 1000 s. Using our GTS method, we could maintain planning target volume (PTV) coverage within 1% error similar to CG, while reducing the organ-at-risk mean dose for body, rectum, left and right femoral heads; the mean dose to bladder was 1% higher with GTS than with CG.
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Alves N, Dias JM, Rocha H, Ventura T, Mateus J, Capela M, Khouri L, Lopes MDC. Assessing the need for adaptive radiotherapy in head and neck cancer patients using an automatic planning tool. Rep Pract Oncol Radiother 2021; 26:423-432. [PMID: 34277096 PMCID: PMC8281904 DOI: 10.5603/rpor.a2021.0056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 02/23/2021] [Indexed: 12/24/2022] Open
Abstract
Background Unbiased analysis of the impact of adaptive radiotherapy (ART) is necessary to evaluate dosimetric benefit and optimize clinics' workflows. The aim of the study was to assess the need for adaptive radiotherapy (ART) in head and neck (H&N) cancer patients using an automatic planning tool in a retrospective planning study. Materials and methods Thirty H&N patients treated with adaptive radiotherapy were analysed. Patients had a CT scan for treatment planning and a verification CT during treatment according to the clinic's protocol. Considering these images, three plans were retrospectively generated using the iCycle tool to simulate the scenarios with and without adaptation: 1) the optimized plan based on the planning CT; 2) the optimized plan based on the verification CT (ART-plan); 3) the plan obtained by considering treatment plan 1 re-calculated in the verification CT (non-ART plan). The dosimetric endpoints for both target volumes and OAR were compared between scenarios 2 and 3 and the SPIDERplan used to evaluate plan quality. Results The most significant impact of ART was found for the PTVs, which demonstrated decreased D98% in the non-ART plan. A general increase in the dose was observed for the OAR but only the spinal cord showed a statistical significance. The SPIDERplan analysis indicated an overall loss of plan quality in the absence of ART. Conclusion These results confirm the advantages of ART in H&N patients, especially for the coverage of target volumes. The usage of an automatic planning tool reduces planner-induced bias in the results, guaranteeing that the observed changes derive from the application of ART.
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Affiliation(s)
- Natália Alves
- Physics Department, Faculty of Science and Technology, University of Coimbra, Coimbra, Portugal
| | - Joana Matos Dias
- Instituto de Engenharia de Sistemas e Computadores de Coimbra, Coimbra, Portugal.,Faculty of Economics, University of Coimbra, Coimbra, Portugal
| | - Humberto Rocha
- Instituto de Engenharia de Sistemas e Computadores de Coimbra, Coimbra, Portugal.,Faculty of Economics, University of Coimbra, Coimbra, Portugal
| | - Tiago Ventura
- Instituto de Engenharia de Sistemas e Computadores de Coimbra, Coimbra, Portugal.,Medical Physics Department, Instituto Português de Oncologia de Coimbra Francisco Gentil, EPE, Coimbra, Portugal
| | - Josefina Mateus
- Medical Physics Department, Instituto Português de Oncologia de Coimbra Francisco Gentil, EPE, Coimbra, Portugal
| | - Miguel Capela
- Medical Physics Department, Instituto Português de Oncologia de Coimbra Francisco Gentil, EPE, Coimbra, Portugal
| | - Leila Khouri
- Radiotherapy Department, Instituto Português de Oncologia de Coimbra Francisco Gentil, EPE, Coimbra, Portugal
| | - Maria do Carmo Lopes
- Instituto de Engenharia de Sistemas e Computadores de Coimbra, Coimbra, Portugal.,Medical Physics Department, Instituto Português de Oncologia de Coimbra Francisco Gentil, EPE, Coimbra, Portugal
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Ventura T, Dias J, Khouri L, Netto E, Soares A, da Costa Ferreira B, Rocha H, Lopes MDC. Clinical validation of a graphical method for radiation therapy plan quality assessment. Radiat Oncol 2020; 15:64. [PMID: 32164752 PMCID: PMC7068922 DOI: 10.1186/s13014-020-01507-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 02/27/2020] [Indexed: 11/26/2022] Open
Abstract
Background This work aims at clinically validating a graphical tool developed for treatment plan assessment, named SPIDERplan, by comparing the plan choices based on its scoring with the radiation oncologists (RO) clinical preferences. Methods SPIDERplan validation was performed for nasopharynx pathology in two steps. In the first step, three ROs from three Portuguese radiotherapy departments were asked to blindly evaluate and rank the dose distributions of twenty pairs of treatment plans. For plan ranking, the best plan from each pair was selected. For plan evaluation, the qualitative classification of ‘Good’, ‘Admissible with minor deviations’ and ‘Not Admissible’ were assigned to each plan. In the second step, SPIDERplan was applied to the same twenty patient cases. The tool was configured for two sets of structures groups: the local clinical set and the groups of structures suggested in international guidelines for nasopharynx cancer. Group weights, quantifying the importance of each group and incorporated in SPIDERplan, were defined according to RO clinical preferences and determined automatically by applying a mixed linear programming model for implicit elicitation of preferences. Intra- and inter-rater ROs plan selection and evaluation were assessed using Brennan-Prediger kappa coefficient. Results Two-thirds of the plans were qualitatively evaluated by the ROs as ‘Good’. Concerning intra- and inter-rater variabilities of plan selection, fair agreements were obtained for most of the ROs. For plan evaluation, substantial agreements were verified in most cases. The choice of the best plan made by SPIDERplan was identical for all sets of groups and, in most cases, agreed with RO plan selection. Differences between RO choice and SPIDERplan analysis only occurred in cases for which the score differences between the plans was very low. A score difference threshold of 0.005 was defined as the value below which two plans are considered of equivalent quality. Conclusion Generally, SPIDERplan response successfully reproduced the ROs plan selection. SPIDERplan assessment performance can represent clinical preferences based either on manual or automatic group weight assignment. For nasopharynx cases, SPIDERplan was robust in terms of the definitions of structure groups, being able to support different configurations without losing accuracy.
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Affiliation(s)
- Tiago Ventura
- Physics department, University of Aveiro, Aveiro, Portugal. .,Medical Physics department, Portuguese Oncology Institute of Coimbra, Coimbra, Portugal. .,Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal.
| | - Joana Dias
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal.,Economy Faculty of University of Coimbra and Centre for Business and Economics Research, Coimbra, Portugal
| | - Leila Khouri
- Radiotherapy department, Portuguese Oncology Institute of Coimbra, Coimbra, Portugal
| | - Eduardo Netto
- Radiotherapy department, Portuguese Oncology Institute of Lisbon, Lisbon, Portugal
| | - André Soares
- Radiotherapy department, Portuguese Oncology Institute of Porto, Porto, Portugal
| | - Brigida da Costa Ferreira
- Physics department, University of Aveiro, Aveiro, Portugal.,Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal.,School Health Polytechnic of Porto, Porto, Portugal
| | - Humberto Rocha
- Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal.,Economy Faculty of University of Coimbra and Centre for Business and Economics Research, Coimbra, Portugal
| | - Maria do Carmo Lopes
- Physics department, University of Aveiro, Aveiro, Portugal.,Medical Physics department, Portuguese Oncology Institute of Coimbra, Coimbra, Portugal.,Institute for Systems Engineering and Computers at Coimbra, Coimbra, Portugal
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