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1.
Br J Radiol ; 93(1107): 20190920, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31944827

RESUMO

OBJECTIVE: For the past 20 years, Paul Scherrer Institut (PSI) has treated more than 1500 patients with deep-seated tumors using PSI-Plan, an in-house developed treatment planning system (TPS) used for proton beam scanning proton therapy, in combination with its home-built gantries. The goal of the present work is to benchmark the performance of a new TPS/Gantry system for proton therapy centers which have established already a baseline standard of care. METHODS AND MATERIALS: A total of 31 cases (=52 plans) distributed around 7 anatomical sites and 12 indications were randomly selected and re-planned using Eclipse™. The resulting plans were compared with plans formerly optimized in PSI-Plan, in terms of target coverage, plan quality, organ-at-risk (OAR) sparing and number of delivered pencil beams. RESULTS: Our results show an improvement on target coverage and homogeneity when using Eclipse™ while PSI-Plan showed superior plan conformity. As for OAR sparing, both TPS achieved the clinical constraints. The number of pencil beams required per plan was on average 3.4 times higher for PSI-Plan. CONCLUSION: Both systems showed a good capacity to produce satisfactory plans, with Eclipse™ being able to achieve better target coverage and plan homogeneity without compromising OARs. ADVANCES IN KNOWLEDGE: A benchmark between a clinically tested and validated system with a commercial solution is of interest for emerging proton therapy, equipped with commercial systems and no previous experience with proton beam scanning.


Assuntos
Benchmarking , Institutos de Câncer , Neoplasias/radioterapia , Terapia com Prótons/instrumentação , Melhoria de Qualidade , Planejamento da Radioterapia Assistida por Computador/normas , Algoritmos , Humanos , Terapia com Prótons/normas , Suíça
2.
Int J Radiat Oncol Biol Phys ; 106(2): 430-439, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31678227

RESUMO

PURPOSE: To evaluate whether automated knowledge-based planning (KBP) (a) is noninferior to human-driven planning across multiple disease sites and (b) systematically affects dosimetric plan quality and variability. METHODS AND MATERIALS: Clinical KBP automated planning routines were developed for prostate, prostatic fossa, hypofractionated lung, and head and neck. Clinical implementation consisted of independent generation of human-generated and KBP plans (145 cases across all sites), followed by blinded plan selection. Reviewing physicians were prompted to select a single plan; when plan equivalence was volunteered, this scored as KBP selection. Plan selection analysis used a noninferiority framework testing the hypothesis that KBP is not worse than human-driven planning (threshold: lower 95% confidence interval [CI] > 0.45 = noninferiority; > 0.5 = superiority). Target and organ-at-risk metrics were compared by dose differencing: ΔDx = Dx, human-Dx, KBP (2-tailed paired t test, Bonferroni-corrected P < .05 significance threshold). To evaluate the aggregated effect of KBP on planning performance, we examined post-KBP dosimetric parameters against 183 plans generated just before KBP implementation (2-tailed unpaired t test, Bonferroni-corrected P < .05). RESULTS: Across all disease sites, the KBP success rate (physician preferred + equivalent) was noninferior compared with human-driven planning (83 of 145 = 57.2%; range, 49.2%-65.3%) but did not cross the threshold for superiority. The KBP success rate in respective disease sites was superior with head and neck ([22 + 2]/36 = 66.7%; 95% CI, 51%-82%) and noninferior for lung stereotactic body radiation therapy ([21 + 2]/36 = 63.9%; 95% CI, 48%-80%) but did not meet noninferiority criteria with prostate ([16 + 3]/41 = 46.3%; 95% CI, 31%-62%) or prostatic fossa ([17 + 0]/32 = 53.1%; 95% CI, 36%-70%). Prostate, prostatic fossa, and head and neck showed significant differences in KBP-selected plans versus human-selected plans, with KBP generally exhibiting greater organ-at-risk sparing and human plans exhibiting better target homogeneity. Analysis of plan quality pre- and post-KBP showed some reductions in organ doses and quality metric variability in prostate and head and neck. CONCLUSIONS: Fully automated KBP was noninferior to human-driven plan optimization across multiple disease sites. Dosimetric analysis of treatment plans before and after KBP implementation showed a systematic shift to higher plan quality and lower variability with the introduction of KBP.


Assuntos
Protocolos Clínicos , Neoplasias de Cabeça e Pescoço/radioterapia , Gestão do Conhecimento , Neoplasias Pulmonares/radioterapia , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Bases de Conhecimento , Neoplasias Pulmonares/patologia , Masculino , Tratamentos com Preservação do Órgão/métodos , Órgãos em Risco , Neoplasias da Próstata/patologia , Garantia da Qualidade dos Cuidados de Saúde , Radiometria , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/normas , Equipolência Terapêutica
3.
Br J Radiol ; 93(1107): 20190669, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31799859

RESUMO

OBJECTIVE: This study is part of ongoing efforts aiming to transit from measurement-based to combined patient-specific quality assurance (PSQA) in intensity-modulated proton therapy (IMPT). A Monte Carlo (MC) dose-calculation algorithm is used to improve the independent dose calculation and to reveal the beam modeling deficiency of the analytical pencil beam (PB) algorithm. METHODS: A set of representative clinical IMPT plans with suboptimal PSQA results were reviewed. Verification plans were recalculated using an MC algorithm developed in-house. Agreements of PB and MC calculations with measurements that quantified by the γ passing rate were compared. RESULTS: The percentage of dose planes that met the clinical criteria for PSQA (>90% γ passing rate using 3%/3 mm criteria) increased from 71.40% in the original PB calculation to 95.14% in the MC recalculation. For fields without beam modifiers, nearly 100% of the dose planes exceeded the 95% γ passing rate threshold using the MC algorithm. The model deficiencies of the PB algorithm were found in the proximal and distal regions of the SOBP, where MC recalculation improved the γ passing rate by 11.27% (p < 0.001) and 16.80% (p < 0.001), respectively. CONCLUSIONS: The MC algorithm substantially improved the γ passing rate for IMPT PSQA. Improved modeling of beam modifiers would enable the use of the MC algorithm for independent dose calculation, completely replacing additional depth measurements in IMPT PSQA program. For current users of the PB algorithm, further improving the long-tail modeling or using MC simulation to generate the dose correction factor is necessary. ADVANCES IN KNOWLEDGE: We justified a change in clinical practice to achieve efficient combined PSQA in IMPT by using the MC algorithm that was experimentally validated in almost all the clinical scenarios in our center. Deficiencies in beam modeling of the current PB algorithm were identified and solutions to improve its dose-calculation accuracy were provided.


Assuntos
Algoritmos , Método de Monte Carlo , Terapia com Prótons/normas , Garantia da Qualidade dos Cuidados de Saúde , Radioterapia de Intensidade Modulada/normas , Análise de Dados , Humanos , Terapia com Prótons/instrumentação , Terapia com Prótons/métodos , Controle de Qualidade , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Planejamento da Radioterapia Assistida por Computador/estatística & dados numéricos , Radioterapia de Intensidade Modulada/instrumentação , Radioterapia de Intensidade Modulada/métodos , Reprodutibilidade dos Testes , Síncrotrons
5.
J Appl Clin Med Phys ; 20(9): 61-68, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31478615

RESUMO

PURPOSE: The purpose of the study was to investigate if surface guided radiotherapy (SGRT) can decrease setup deviations for tangential and locoregional breast cancer patients compared to conventional laser-based setup (LBS). MATERIALS AND METHODS: Both tangential (63 patients) and locoregional (76 patients) breast cancer patients were enrolled in this study. For LBS, the patients were positioned by aligning skin markers to the room lasers. For the surface based setup (SBS), an optical surface scanning system was used for daily setup using both single and three camera systems. To compare the two setup methods, the patient position was evaluated using verification imaging (field images or orthogonal images). RESULTS: For both tangential and locoregional treatments, SBS decreased the setup deviation significantly compared to LBS (P < 0.01). For patients receiving tangential treatment, 95% of the treatment sessions were within the clinical tolerance of ≤ 4 mm in any direction (lateral, longitudinal or vertical) using SBS, compared to 84% for LBS. Corresponding values for patients receiving locoregional treatment were 70% and 54% for SBS and LBS, respectively. No significant difference was observed comparing the setup result using a single camera system or a three camera system. CONCLUSIONS: Conventional laser-based setup can with advantage be replaced by surface based setup. Daily SGRT improves patient setup without additional imaging dose to breast cancer patients regardless if a single or three camera system was used.


Assuntos
Braquiterapia/normas , Neoplasias da Mama/radioterapia , Posicionamento do Paciente , Planejamento da Radioterapia Assistida por Computador/normas , Erros de Configuração em Radioterapia/prevenção & controle , Radioterapia Guiada por Imagem/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/diagnóstico por imagem , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Pessoa de Meia-Idade , Órgãos em Risco/efeitos da radiação , Prognóstico , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
6.
Technol Cancer Res Treat ; 18: 1533033819873922, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31495281

RESUMO

Treatment planning is an essential step of the radiotherapy workflow. It has become more sophisticated over the past couple of decades with the help of computer science, enabling planners to design highly complex radiotherapy plans to minimize the normal tissue damage while persevering sufficient tumor control. As a result, treatment planning has become more labor intensive, requiring hours or even days of planner effort to optimize an individual patient case in a trial-and-error fashion. More recently, artificial intelligence has been utilized to automate and improve various aspects of medical science. For radiotherapy treatment planning, many algorithms have been developed to better support planners. These algorithms focus on automating the planning process and/or optimizing dosimetric trade-offs, and they have already made great impact on improving treatment planning efficiency and plan quality consistency. In this review, the smart planning tools in current clinical use are summarized in 3 main categories: automated rule implementation and reasoning, modeling of prior knowledge in clinical practice, and multicriteria optimization. Novel artificial intelligence-based treatment planning applications, such as deep learning-based algorithms and emerging research directions, are also reviewed. Finally, the challenges of artificial intelligence-based treatment planning are discussed for future works.


Assuntos
Inteligência Artificial , Neoplasias/radioterapia , Planejamento da Radioterapia Assistida por Computador , Algoritmos , Humanos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Fluxo de Trabalho
7.
J Appl Clin Med Phys ; 20(9): 163-165, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31536666

RESUMO

PURPOSE: Compliance with TG-263 nomenclature standards can be challenging. We introduce an open source solution to this problem and evaluate its impact on compliance within our institution. MATERIALS/METHODS: The TG-236 nomenclature standards were implemented in our clinic in two phases. In phase 1, we deployed TG-263 compliant templates for each disease site. In phase 2, we developed and deployed a script for evaluating compliance which presented errors to the user. After each phase the compliance was recorded. RESULTS: Mean compliance errors prior to phase 1 was 31.8% ± 17.4%. Error rates dropped to 8.1% ± 12.2% across phase 1 and dropped further to 2.2% ± 6.9% during the automation system deployed in phase 2. CONCLUSION: Both structure templates and automation scripts are very useful for increasing compliance with structure naming standards. Our software solution is made available on GitHub for other institutions to implement.


Assuntos
Neoplasias/classificação , Neoplasias/radioterapia , Garantia da Qualidade dos Cuidados de Saúde/normas , Radioterapia (Especialidade) , Planejamento da Radioterapia Assistida por Computador/normas , Terminologia como Assunto , Humanos , Dosagem Radioterapêutica
8.
J Appl Clin Med Phys ; 20(9): 69-77, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31538720

RESUMO

PURPOSE: To quantify the effects of combining layer-based repainting and respiratory gating as a strategy to mitigate the dosimetric degradation caused by the interplay effect between a moving target and dynamic spot-scanning proton delivery. METHODS: An analytic routine modeled three-dimensional dose distributions of pencil-beam proton plans delivered to a moving target. Spot positions and weights were established for a single field to deliver 100 cGy to a static, 15-cm deep, 3-cm radius spherical clinical target volume with a 1-cm isotropic internal target volume expansion. The interplay effect was studied by modeling proton delivery from a clinical synchrotron-based spot scanning system and respiratory target motion, patterned from surrogate patient breathing traces. Motion both parallel and orthogonal to the beam scanning direction was investigated. Repainting was modeled using a layer-based technique. For each of 13 patient breathing traces, the dose from 20 distinct delivery schemes (combinations of four gate window amplitudes and five repainting techniques) was computed. Delivery strategies were inter-compared based on target coverage, dose homogeneity, high dose spillage, and delivery time. RESULTS: Notable degradation and variability in plan quality were observed for ungated delivery. Decreasing the gate window reduced this variability and improved plan quality at the expense of longer delivery times. Dose deviations were substantially greater for motion orthogonal to the scan direction when compared with parallel motion. Repainting coupled with gating was effective at partially restoring dosimetric coverage at only a fraction of the delivery time increase associated with very small gate windows alone. Trends for orthogonal motion were similar, but more complicated, due to the increased severity of the interplay. CONCLUSIONS: Layer-based repainting helps suppress the interplay effect from intra-gate motion, with only a modest penalty in delivery time. The magnitude of the improvement in target coverage is strongly influenced by individual patient breathing patterns and the tumor motion trajectory.


Assuntos
Movimento , Neoplasias/radioterapia , Imagens de Fantasmas , Terapia com Prótons/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Síncrotrons/instrumentação , Tomografia Computadorizada Quadridimensional , Humanos , Órgãos em Risco/efeitos da radiação , Radiometria/métodos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos
9.
Cancer Radiother ; 23(6-7): 630-635, 2019 Oct.
Artigo em Francês | MEDLINE | ID: mdl-31447339

RESUMO

The use of stereotactic body radiotherapy (SBRT) has increased rapidly over the past decade. Optimal preservation of normal tissues is a major issue because of their high sensitivity to high doses per session. Extreme hypofractionation can convert random errors into systematic errors. Optimal preservation of organs at risk requires first of all a rigorous implementation of this technique according to published guidelines. The robustness of the imaging modalities used for planning, and training medical and paramedical staff are an integral part of these guidelines too. The choice of SBRT indications, dose fractionation, dose heterogeneity, ballistics, are also means of optimizing the protection of normal tissues. Non-coplanarity and tracking of moving targets allow dosimetric improvement in some clinical settings. Automatic planning could also improve normal tissue protection. Adaptive SBRT, with new image guided radiotherapy modalities such as MRI, could further reduce the risk of toxicity.


Assuntos
Órgãos em Risco/efeitos da radiação , Lesões por Radiação/prevenção & controle , Radiocirurgia/métodos , Radioterapia Guiada por Imagem/métodos , Fracionamento da Dose de Radiação , Humanos , Imagem por Ressonância Magnética Intervencionista/métodos , Erros Médicos/prevenção & controle , Hipofracionamento da Dose de Radiação , Radiocirurgia/educação , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/normas
10.
Int J Radiat Oncol Biol Phys ; 105(4): 893-902, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31377162

RESUMO

PURPOSE: To assess the accuracy of machine learning to predict and classify quality assurance (QA) results for volumetric modulated arc therapy (VMAT) plans. METHODS AND MATERIALS: Three hundred three VMAT plans, including 176 gynecologic cancer and 127 head and neck cancer plans, were chosen in this study. Fifty-four complexity metrics were extracted from the QA plans and considered as inputs. Patient-specific QA was performed, and gamma passing rates (GPRs) were used as outputs. One Poisson lasso (PL) regression model was developed, aiming to predict individual GPR, and 1 random forest (RF) classification model was developed to classify QA results as "pass" or "fail." Both technical validation (TV) and clinical validation (CV) were used to evaluate the model reliability. GPR prediction accuracy of PL and classification performance of PL and RF were evaluated. RESULTS: In TV, the mean prediction error of PL was 1.81%, 2.39%, and 4.18% at 3%/3 mm, 3%/2 mm, and 2%/2 mm, respectively. No significant differences in prediction errors between TV and CV were observed. In QA results classification, PL had a higher specificity (accurately identifying plans that can pass QA), whereas RF had a higher sensitivity (accurately identifying plans that may fail QA). By using 90% as the action limit at a 3%/2 mm criterion, the specificity of PL and RF was 97.5% and 87.7% in TV and 100% and 71.4% in CV, respectively. The sensitivity of PL and RF was 31.6% and 100% in TV and 33.3% and 100% in CV, respectively. With 100% sensitivity, the QA workload of 81.2% of plans in TV and 62.5% of plans in CV could be reduced by RF. CONCLUSIONS: The PL model could accurately predict GPR for most VMAT plans. The RF model with 100% sensitivity was preferred for QA results classification. Machine learning can be a useful tool to assist VMAT QA and reduce QA workload.


Assuntos
Neoplasias dos Genitais Femininos/radioterapia , Neoplasias de Cabeça e Pescoço/radioterapia , Aprendizado de Máquina/normas , Garantia da Qualidade dos Cuidados de Saúde/normas , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia de Intensidade Modulada/normas , Confiabilidade dos Dados , Feminino , Humanos , Distribuição de Poisson , Garantia da Qualidade dos Cuidados de Saúde/classificação , Análise de Regressão , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Carga de Trabalho
11.
Technol Cancer Res Treat ; 18: 1533033819871621, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31451059

RESUMO

PURPOSE: To compare plan quality and delivery efficiency of noncoplanar volumetric modulated arc therapy with coplanar volumetric modulated arc therapy, intensity-modulated radiation therapy, and CyberKnife for multiple brain metastases. METHODS: For 15 patients with multiple brain metastases, noncoplanar volumetric modulated arc therapy, coplanar volumetric modulated arc therapy, intensity-modulated radiation therapy, and CyberKnife plans with a prescription dose of 30 Gy in 3 fractions were generated. Noncoplanar volumetric modulated arc therapy and coplanar volumetric modulated arc therapy plans consisted of 4 noncoplanar arcs and 2 full coplanar arcs, respectively. Intensity-modulated radiation therapy plans consisted of 7 coplanar fields. CyberKnife plans used skull tracking to ensure accurate position. All plans were generated to cover 95% target volume with prescription dose. Gradient index, conformity index, normal brain tissue volume (V 3Gy - V 24Gy), monitor units, and beam on time were evaluated. RESULTS: Gradient index was the lowest for CyberKnife (3.49 ± 0.65), followed by noncoplanar volumetric modulated arc therapy (4.21 ± 1.38), coplanar volumetric modulated arc therapy (4.87 ± 1.35), and intensity-modulated radiation therapy (5.36 ± 1.98). Conformity index was the largest for noncoplanar volumetric modulated arc therapy (0.87 ± 0.03), followed by coplanar volumetric modulated arc therapy (0.86 ± 0.04), CyberKnife (0.86 ± 0.07), and intensity-modulated radiation therapy (0.85 ± 0.05). Normal brain tissue volume at high-to-moderate dose spreads (V 24Gy - V 9Gy) was significantly reduced in noncoplanar volumetric modulated arc therapy over that of intensity-modulated radiation therapy and coplanar volumetric modulated arc therapy. Normal brain tissue volume for noncoplanar volumetric modulated arc therapy was comparable with noncoplanar volumetric modulated arc therapy at high-dose level (V 24Gy - V 15Gy) and larger than CyberKnife at moderate-to-low dose level (V 12Gy - V 3Gy). Monitor units was highest for CyberKnife (28 733.59 ± 7197.85), followed by intensity-modulated radiation therapy (4128.40 ± 1185.38), noncoplanar volumetric modulated arc therapy (3105.20 ± 371.23), and coplanar volumetric modulated arc therapy (2997.27 ± 446.84). Beam on time was longest for CyberKnife (30.25 ± 7.32 minutes), followed by intensity-modulated radiation therapy (2.95 ± 0.85 minutes), noncoplanar volumetric modulated arc therapy (2.61 ± 0.07 minutes), and coplanar volumetric modulated arc therapy (2.30 ± 0.23 minutes). CONCLUSION: For brain metastases far away from organs-at-risk, noncoplanar volumetric modulated arc therapy generated more rapid dose falloff and higher conformity compared to intensity-modulated radiation therapy and coplanar volumetric modulated arc therapy. Noncoplanar volumetric modulated arc therapy provided a comparable dose falloff with CyberKnife at high-dose level and a slower dose falloff than CyberKnife at moderate-to-low dose level. Noncoplanar volumetric modulated arc therapy plans had less monitor units and shorter beam on time than CyberKnife plans.


Assuntos
Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Radiocirurgia , Radioterapia de Intensidade Modulada , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Órgãos em Risco , Garantia da Qualidade dos Cuidados de Saúde , Radiometria , Radiocirurgia/métodos , Radiocirurgia/normas , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia Guiada por Imagem/métodos , Radioterapia Guiada por Imagem/normas , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Resultado do Tratamento , Carga Tumoral
12.
J Appl Clin Med Phys ; 20(8): 56-64, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31423729

RESUMO

PURPOSE: To develop and implement an automated plan check (APC) tool using a Six Sigma methodology with the aim of improving safety and efficiency in external beam radiotherapy. METHODS: The Six Sigma define-measure-analyze-improve-control (DMAIC) framework was used by measuring defects stemming from treatment planning that were reported to the departmental incidence learning system (ILS). The common error pathways observed in the reported data were combined with our departmental physics plan check list, and AAPM TG-275 identified items. Prioritized by risk priority number (RPN) and severity values, the check items were added to the APC tool developed using Varian Eclipse Scripting Application Programming Interface (ESAPI). At 9 months post-APC implementation, the tool encompassed 89 check items, and its effectiveness was evaluated by comparing RPN values and rates of reported errors. To test the efficiency gains, physics plan check time and reported error rate were prospectively compared for 20 treatment plans. RESULTS: The APC tool was successfully implemented for external beam plan checking. FMEA RPN ranking re-evaluation at 9 months post-APC demonstrated a statistically significant average decrease in RPN values from 129.2 to 83.7 (P < .05). After the introduction of APC, the average frequency of reported treatment-planning errors was reduced from 16.1% to 4.1%. For high-severity errors, the reduction was 82.7% for prescription/plan mismatches and 84.4% for incorrect shift note. The process shifted from 4σ to 5σ quality for isocenter-shift errors. The efficiency study showed a statistically significant decrease in plan check time (10.1 ± 7.3 min, P = .005) and decrease in errors propagating to physics plan check (80%). CONCLUSIONS: Incorporation of APC tool has significantly reduced the error rate. The DMAIC framework can provide an iterative and robust workflow to improve the efficiency and quality of treatment planning procedure enabling a safer radiotherapy process.


Assuntos
Automação , Neoplasias/radioterapia , Garantia da Qualidade dos Cuidados de Saúde/normas , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Software , Lista de Checagem , Humanos , Órgãos em Risco/efeitos da radiação , Estudos Prospectivos , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/métodos , Gestão da Qualidade Total
13.
J Appl Clin Med Phys ; 20(8): 29-35, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31313508

RESUMO

Recently, there has been an increased interest in the feasibility and impact of automation within the field of medical dosimetry. While there have been many commercialized solutions for automatic treatment planning, the use of an application programming interface to achieve complete plan generation for specific treatment sites is a process only recently available for certain commercial vendors. Automatic plan generation for 20 prostate patients was achieved via a stand-alone automated planning script that accessed a knowledge-based planning solution. Differences between the auto plans and clinically treated, baseline plans were analyzed and compared. The planning script successfully initialized a treatment plan, accessed the knowledge-based planning model, optimized the plan, assessed for constraint compliance, and normalized the treatment plan for maximal coverage while meeting constraints. Compared to baseline plans, the auto-generated plans showed significantly improved rectal sparing with similar coverage for targets and comparable doses to the remaining organs-at-risk. Utilization of a script, with its associated time saving and integrated process management, can quickly and automatically generate an acceptable clinical treatment plan for prostate cancer with either improved or similar results compared to a manually created plan.


Assuntos
Automação , Planejamento de Assistência ao Paciente/normas , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia de Intensidade Modulada/métodos , Algoritmos , Humanos , Bases de Conhecimento , Masculino , Dosagem Radioterapêutica , Software
14.
PLoS One ; 14(7): e0220039, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31329641

RESUMO

PURPOSE: This study compares the plan quality of magnetic-resonance image (MRI)-based intensity modulated radiation therapy (IMRT) using a linac (MR-linac-IMRT), MRI-based IMRT using tri-Co-60 sources (MR-Co-60-IMRT), and volumetric modulated arc therapy (VMAT) for spine stereotactic ablative radiotherapy (SABR). METHODS: Twenty patients with thoracic spine metastasis were retrospectively selected for this study. For each patient, the MR-linac-IMRT, MR-Co-60-IMRT, and VMAT plans were generated using an identical CT image set and structures, except for the spinal cord and spinal cord planning organ-at-risk volume (PRV). Those two structures were contoured based on CT image sets for VMAT planning while those were contoured based on MR image sets for MR-linac-IMRT and MR-Co-60-IMRT planning. The initial prescription doses were 18 Gy in a single fraction for every plan in this study. If the tolerance level of the spinal cord was not met, the prescription doses were reduced to meet the tolerance level of the spinal cord. Dose-volumetric parameters of each plan were analyzed. RESULTS: The average spinal cord volumes contoured based on the CT and MR images were 3.8±1.6 cm3 and 1.1±1.0 cm3, respectively (p<0.001). For four patients, the prescription doses of VMAT plans were reduced to 16 Gy to satisfy the spinal cord tolerance level. For thirteen patients, the prescription doses of MR-Co-60-IMRT plans were reduced to be less than 16 Gy to meet the spinal cord tolerance level. However, for every MR-linac-IMRT plan, the initial prescription doses of 18 Gy could be delivered to the target volume while satisfying the spinal cord tolerance. The average values of D10%, V10Gy, and V14Gy of the spinal cord PRV consistently indicated that the doses to the spinal cord PRV in the MR-linac-IMRT plans were the lowest among three types of plans in this study (all with p≤0.003). CONCLUSION: MR-linac-IMRT appears promising for spine SABR.


Assuntos
Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Neoplasias da Coluna Vertebral/radioterapia , Humanos , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/normas , Aceleradores de Partículas , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia de Intensidade Modulada/instrumentação , Radioterapia de Intensidade Modulada/normas , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/normas
15.
Int J Radiat Oncol Biol Phys ; 105(2): 329-337, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31299242

RESUMO

PURPOSE: The ongoing phase 2/3 PRODIGE 26/CONCORDE trial compares chemoradiation therapy with and without dose escalation in patients with locally advanced or unresectable esophageal cancer. The results of a benchmark case procedure are reported here to evaluate the protocol compliance of participating centers as part of quality assurance for radiation therapy. METHODS AND MATERIALS: Volume delineation, target coverage, and dose constraints to the organs at risk (OARs) were assessed on treatment plans of a common benchmark case performed by each participating center. The centers were classified in 3 categories: per protocol, minor acceptable deviation (MiD), or major unacceptable deviation (MaD). A plan was rejected if ≥4 MiDs or 1 MaD were found. RESULTS: Thirty-5 centers submitted 43 plans. Among them, 14 (32.6%) were per protocol, 19 (44.2%) presented at least 1 MiD, 2 (4.6%) presented at least 1 MaD, and 8 (18.6%) presented both MiD and MaD. Overall, 11 (25.6%) plans were rejected. Only 1 plan was rejected because gross tumor volume was not correctly delineated. The OAR delineation was respected in all cases. Dose constraints to the OARs were respected in the majority of cases except for the heart, where one-third of the plans presented a deviation. As for the target volume, 3 plans (5.8%) had a major underdosage and 1 plan (1.9%) had a major overdosage. Overall, 58% of all treatments were planned with intensity modulated radiation therapy, whereas 42% were planned with 3-dimensional chemoradiation therapy. Significantly more plans in the intensity modulated radiation therapy group were accepted compared with the 3-dimensional chemoradiation therapy group (P = .03). CONCLUSION: The high frequency of protocol deviations underlines the importance of a quality assurance program in clinical trials. Further work should assess the impact of quality assurance for radiation therapy on patient outcomes.


Assuntos
Carcinoma de Células Escamosas/diagnóstico por imagem , Quimiorradioterapia/normas , Neoplasias Esofágicas/diagnóstico por imagem , Órgãos em Risco/diagnóstico por imagem , Garantia da Qualidade dos Cuidados de Saúde , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia de Intensidade Modulada/normas , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Benchmarking , Institutos de Câncer/classificação , Institutos de Câncer/normas , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia/métodos , Cisplatino/administração & dosagem , Esquema de Medicação , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/terapia , Fluoruracila/administração & dosagem , França , Fidelidade a Diretrizes/classificação , Fidelidade a Diretrizes/normas , Fidelidade a Diretrizes/estatística & dados numéricos , Coração/efeitos da radiação , Humanos , Rim/diagnóstico por imagem , Leucovorina/administração & dosagem , Fígado/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Irradiação Linfática/métodos , Irradiação Linfática/normas , Masculino , Compostos Organoplatínicos/administração & dosagem , Órgãos em Risco/efeitos da radiação , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/classificação , Planejamento da Radioterapia Assistida por Computador/estatística & dados numéricos , Radioterapia Conformacional/normas , Medula Espinal/diagnóstico por imagem , Carga Tumoral
16.
Acta Oncol ; 58(9): 1275-1282, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31257960

RESUMO

Introduction: Stereotactic radiosurgery (SRS) is a promising treatment option for patients with multiple brain metastases (BM). Recent technical advances have made LINAC based SRS a patient friendly technique, allowing for accurate patient positioning and a short treatment time. Since SRS is increasingly being used for patients with multiple BM, it remains essential that SRS be performed with the highest achievable quality in order to prevent unnecessary complications such as radionecrosis. The purpose of this article is to provide guidance for high-quality LINAC based SRS for patients with BM, with a focus on single isocenter non-coplanar volumetric modulated arc therapy (VMAT). Methods: The article is based on a consensus statement by the study coordinators and medical physicists of four trials which investigated whether patients with multiple BM are better palliated with SRS instead of whole brain radiotherapy (WBRT): A European trial (NCT02353000), two American trials and a Canadian CCTG lead intergroup trial (CE.7). This manuscript summarizes the quality assurance measures concerning imaging, planning and delivery. Results: To optimize the treatment, the interval between the planning-MRI (gadolinium contrast-enhanced, maximum slice thickness of 1.5 mm) and treatment should be kept as short as possible (< two weeks). The BM are contoured based on the planning-MRI, fused with the planning-CT. GTV-PTV margins are minimized or even avoided when possible. To maximize efficiency, the preferable technique is single isocenter (non-)coplanar VMAT, which delivers high doses to the target with maximal sparing of the organs at risk. The use of flattening filter free photon beams ensures a lower peripheral dose and shortens the treatment time. To bench mark SRS treatment plan quality, it is advisable to compare treatment plans between hospitals. Conclusion: This paper provides guidance for quality assurance and optimization of treatment delivery for LINAC-based radiosurgery for patients with multiple BM.


Assuntos
Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Radiocirurgia/métodos , Radioterapia de Intensidade Modulada/métodos , Neoplasias Encefálicas/diagnóstico por imagem , Ensaios Clínicos como Assunto , Consenso , Meios de Contraste , Gadolínio , Humanos , Imagem por Ressonância Magnética/métodos , Imagem Multimodal , Posicionamento do Paciente , Seleção de Pacientes , Garantia da Qualidade dos Cuidados de Saúde , Radiocirurgia/normas , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia de Intensidade Modulada/normas , Tomografia Computadorizada por Raios X
17.
J Appl Clin Med Phys ; 20(7): 193-200, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31282112

RESUMO

PURPOSE: In this work we have developed a novel method of dose distribution comparison, the inverse gamma (IG) evaluation, by modifying the commonly used gamma evaluation method. METHODS: The IG evaluation calculates the gamma criteria (dose difference criterion, ΔD, or distance-to-agreement criterion, Δd) that are needed to achieve a predefined pass rate or gamma agreement index (GAI). In-house code for evaluating IG with a fixed ΔD of 3% was developed using Python (v3.5.2) and investigated using treatment plans and measurement data from 25 retrospective patient specific quality assurance tests (53 individual arcs). RESULTS: It was found that when the desired GAI was set to 95%, approximately three quarters of the arcs tested were able to achieve Δd within 1 mm (mean Δd: 0.7 ± 0.5 mm). The mean Δd required in order for all points to pass the gamma evaluation (i.e., GAI = 100%) was 4.5 ± 3.1 mm. The possibility of evaluating IG by fixing the Δd or ΔD/Δd, instead of fixing the ΔD at 3%, was also investigated. CONCLUSION: The IG method and its indices have the potential to be implemented clinically to quantify the minimum dose and distance criteria based on a specified GAI. This method provides additional information to augment standard gamma evaluation results during patient specific quality assurance testing of individual treatment plans. The IG method also has the potential to be used in retrospective audits to determine an appropriate set of local gamma criteria and action levels based on a cohort of patient specific quality assurance plans.


Assuntos
Algoritmos , Raios gama , Neoplasias/radioterapia , Garantia da Qualidade dos Cuidados de Saúde/normas , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia de Intensidade Modulada/normas , Humanos , Controle de Qualidade , Dosagem Radioterapêutica , Estudos Retrospectivos , Software
18.
Int J Radiat Oncol Biol Phys ; 105(3): 514-524, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31306734

RESUMO

PURPOSE: To benchmark and improve, through means of a targeted intervention, the quality of intensity modulated radiation therapy treatment planning for locally advanced head and neck cancer (HNC) in the Netherlands. The short and long-term impact of this intervention was assessed. METHODS AND MATERIALS: A delineated computed tomography-scan of an oropharynx HNC case was sent to all 15 Dutch radiation therapy centers treating HNC. Aims for planning target volume and organ-at-risk (OAR) dosimetry were established by consensus. Each center generated a treatment plan. In a targeted intervention, OAR sparing of all plans was discussed, and centers with the best OAR sparing shared their planning strategies. Impact of the intervention was assessed by (1) short-term (half a year after intervention) replanning of the original case and (2) long-term (1 and 3 years after intervention) planning of new cases. RESULTS: Benchmarking revealed substantial difference in OAR doses. Initial mean doses were 22 Gy (range, 15-31 Gy), 35 Gy (18-49 Gy), and 37 Gy (20-46 Gy) for the contralateral parotid gland, contralateral submandibular gland, and combined swallowing structures, respectively. Replanning after targeted intervention significantly reduced mean doses and variation, but clinically relevant differences still remained: 18 Gy (14-22 Gy), 28 Gy (17-45 Gy), and 29 Gy (18-39 Gy), respectively. One and 3 years later the variation remained stable. CONCLUSIONS: Despite many years of HNC intensity modulated radiation therapy experience, initial treatment plans showed surprisingly large variations. The simple targeted intervention used in this analysis improved OAR sparing, and its impact was durable; however, fairly large dose differences still continue to exist. Additional work is needed to understand these variations and to minimize them. A national radiation oncology platform can be instrumental for developing and maintaining high-quality planning protocols.


Assuntos
Benchmarking/métodos , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/radioterapia , Tratamentos com Preservação do Órgão/métodos , Órgãos em Risco/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia de Intensidade Modulada/normas , Benchmarking/normas , Pesquisas sobre Serviços de Saúde , Humanos , Países Baixos , Tratamentos com Preservação do Órgão/normas , Órgãos em Risco/diagnóstico por imagem , Glândula Parótida/diagnóstico por imagem , Glândula Parótida/efeitos da radiação , Músculos Faríngeos/diagnóstico por imagem , Músculos Faríngeos/efeitos da radiação , Melhoria de Qualidade , Doses de Radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Glândula Submandibular/diagnóstico por imagem , Glândula Submandibular/efeitos da radiação , Fatores de Tempo , Língua/diagnóstico por imagem , Língua/efeitos da radiação , Neoplasias Tonsilares/diagnóstico por imagem , Neoplasias Tonsilares/radioterapia
19.
Br J Radiol ; 92(1102): 20190270, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31295002

RESUMO

Modulated radiotherapy with multileaf collimators is widely used to improve target conformity and normal tissue sparing. This introduced an additional degree of complexity, studied by multiple teams through different properties. Three categories of complexity metrics were considered in this review: fluence, deliverability and accuracy metrics. The first part of this review is dedicated to the inventory of these complexity metrics. Different applications of these metrics emerged. Influencing the optimizer by integrating complexity metrics into the cost function has been little explored and requires more investigations. In modern treatment planning system, it remains confined to MUs or treatment time limitation. A large majority of studies calculated metrics only for analysis, without plan modification. The main application was to streamline the patient specific quality assurance workload, investigating the capability of complexity metrics to predict patient specific quality assurance results. Additionally complexity metrics were used to analyze behaviour of TPS optimizer, compare TPS, operators and plan properties, and perform multicentre audit. Their potential was also explored in the context of adaptive radiotherapy and automation planning. The second part of the review gives an overview of these studies based on the complexity metrics.


Assuntos
Garantia da Qualidade dos Cuidados de Saúde , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Humanos , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia de Intensidade Modulada/normas
20.
J Appl Clin Med Phys ; 20(8): 105-113, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31355998

RESUMO

PURPOSE: In this study we calculate composite dose delivered to the prostate by using the Calypso tracking -data- stream acquired during patient treatment in our clinic. We evaluate the composite distributions under multiple simulated Calypso tolerance level schemes and then recommend a tolerance level. MATERIALS AND METHODS: Seven Calypso-localized prostate cancer patients treated in our clinic were selected for retrospective analysis. Two different IMRT treatment plans, with prostate PTV margins of 5 and 3 mm respectively, were computed for each patient. A delivered composite dose distribution was computed from Calypso tracking data for each plan. Additionally, we explored the dosimetric implications for "worst case" scenarios by assuming that the prostate position was located at one of the eight extreme corners of a 3 or 5 mm "box." To characterize plan quality under each of the studied scenarios, we recorded the maximum, mean, and minimum doses and volumetric coverage for prostate, PTV, bladder, and rectum. RESULTS AND DISCUSSIONS: Calculated composite dose distributions were very similar to the original plan for all patients. The difference in maximum, mean, and minimum doses as well as volumetric coverage for the prostate, PTV, bladder, and rectum were all < 4.0% of prescription dose. Even for worst scenario cases, the results show acceptable isodose distribution, with the exception for the combination of a 3 mm PTV margin with a 5 mm position tolerance scheme. CONCLUSIONS: Calculated composite dose distributions show that the vast majority of dosimetric metrics agreed well with the planned dose (within 2%). With significant/detrimental deviations from the planned dose only occurring with the combination of a 3 mm PTV margin and 5 mm position tolerance, the 3 mm position tolerance strategy appears reasonable, confirming that further reducing prostate PTV margins to 3 mm is possible when using Calypso with a position tolerance of 3 mm.


Assuntos
Posicionamento do Paciente , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Tomografia Computadorizada por Raios X/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Prognóstico , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos
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