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1.
Cancer Radiother ; 23(6-7): 581-591, 2019 Oct.
Artigo em Francês | MEDLINE | ID: mdl-31473088

RESUMO

Intensity modulated radiotherapy combined with image guided radiotherapy has led to increase the precision of external beam radiotherapy. However, intra or inter-fraction anatomical variations are frequent during the treatment course and can cause under-dosing of the target volume and/or over-dosing of the organs at risk. Several adaptive radiotherapy (ART) strategies can be defined to compensate these anatomical variations. The purpose of this article is to provide an overview of available ART strategies: offline, online, hybrid (library of treatment plans) or in real-time, while considering the arrival of MR-Linac devices in radiotherapy departments. The tools required to these ART strategies such as auto-segmentation, deformable image registration, calculation of the daily dose or dose accumulation, are also described. Implementing an ART strategy requires a rigorous quality assurance process, at each stage and on the entire workflow, as well as prior organization and training from of all the trades. A strong multidisciplinary involvement is finally required in order to ensure ART treatments.


Assuntos
Órgãos em Risco/efeitos da radiação , Garantia da Qualidade dos Cuidados de Saúde , Lesões por Radiação/prevenção & controle , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Neoplasias/radioterapia , Dosagem Radioterapêutica , Radioterapia de Alta Energia , Radioterapia Guiada por Imagem/instrumentação , Radioterapia de Intensidade Modulada/instrumentação
2.
Cancer Radiother ; 23(5): 416-422, 2019 Sep.
Artigo em Francês | MEDLINE | ID: mdl-31421998

RESUMO

This article provides a proposal for the selection and delineation of clinical target volumes for the treatment with radiation of submandibular glands tumours. This article does not deal with external radiotherapy indications but specifies the volumes to be treated if radiotherapy is chosen. High-risk and low-risk peritumoral clinical target volumes are described based on the probability of local tumoral spread. High-risk and low-risk clinical target volumes are illustrated on CT-scan slices. A proposal for the selection of nodal clinical target volumeis also proposed.


Assuntos
Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias da Glândula Submandibular/radioterapia , Humanos , Irradiação Linfática/métodos , Imagem por Ressonância Magnética , Invasividade Neoplásica , Tamanho do Órgão , Dosagem Radioterapêutica , Risco , Neoplasias da Glândula Submandibular/diagnóstico por imagem , Neoplasias da Glândula Submandibular/patologia , Tomografia Computadorizada por Raios X , Carga Tumoral
3.
Anticancer Res ; 39(8): 4351-4356, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366529

RESUMO

BACKGROUND/AIM: To evaluate the effectiveness of diaphragm matching (DM) for carbon-ion radiotherapy (CIRT) of pancreatic cancer patients and develop a simple method to estimate tumour position. PATIENTS AND METHODS: Treatment planning CTs from 27 pancreatic cancer patients treated with CIRT in our facility were used in this study, and 32 other CT image datasets taken on different days were used for measuring tumour and diaphragm displacements. A correction method (SI-correction) was developed using the coefficient x of the regression line formula for the displacements between the diaphragm and tumour in the superior-inferior direction. The tumour positioning errors of bone matching (BM), DM, and SI-correction were measured. RESULTS: Mean (±standard deviation) absolute errors of BM, DM, and SI-correction were 5.10±3.31, 7.48±4.04, and 4.13±2.51 mm, respectively. DM showed significant differences compared to the other correction methods. CONCLUSION: DM was subject to larger errors than BM. Our correction method improved positional errors.


Assuntos
Diafragma/diagnóstico por imagem , Radioterapia com Íons Pesados/métodos , Neoplasias Pancreáticas/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Idoso , Tomografia Computadorizada de Feixe Cônico , Diafragma/efeitos da radiação , Feminino , Humanos , Masculino , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Posicionamento do Paciente , Radioterapia Guiada por Imagem , Tomografia Computadorizada por Raios X
4.
Cancer Radiother ; 23(6-7): 592-608, 2019 Oct.
Artigo em Francês | MEDLINE | ID: mdl-31427077

RESUMO

Adaptive radiotherapy (ART) is a complexe image-guided radiotherapy modality that comprises multiple planning to account for anatomical variations occurring during irradiation. Schematically, two strategies of RTA can be distinguished and combined according to tumor locations. One or more replanning can be proposed to correct systematic variations such as tumor shrinkage. A library of treatment plans with day-to-day plan selection from cone-beam CT imaging can also be proposed to correct random variations such as uterine motion or bladder/rectum volume changes. Because of strong anatomical variations occurring during irradiation, RTA appears therefore particularly justified in head and neck, lung, bladder, cervical and rectum and pancreas tumors, and to a lesser extent for prostate tumors and other digestive tumors. For these tumor locations, ART provides a fairly clear dosimetric benefit but a clinical benefit not yet formally demonstrated. ART cannot be proposed in a routine practice but must be evaluated medico-economically in the context of prospective trials. A rigorous quality control must be associated.


Assuntos
Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/métodos , Feminino , Neoplasias Gastrointestinais/radioterapia , Humanos , Neoplasias Pulmonares/radioterapia , Masculino , Neoplasias Otorrinolaringológicas/radioterapia , Neoplasias da Próstata/radioterapia , Neoplasias da Bexiga Urinária/radioterapia , Neoplasias do Colo do Útero/radioterapia
5.
Cancer Radiother ; 23(6-7): 753-760, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31427076

RESUMO

Imaging provides the basis for radiotherapy. Multi-modality images are used for target delineation (primary tumor and nodes, boost volume) and organs at risk, treatment guidance, outcome prediction, and treatment assessment. Next to anatomical information, more and more functional imaging is being used. The current paper provides a brief overview of the different applications of imaging techniques used in the radiotherapy process, focusing on uncertainties and QA. The paper mainly focuses on PET and MRI, but also provides a short discussion on DCE-CT. A close collaboration between radiology, nuclear medicine and radiotherapy departments provides the key to improve the quality of radiotherapy. Jointly developed imaging protocols (RT position setup, immobilization tools, lasers, flat table…), and QA programs are mandatory. For PET, suitable windowing in consultation with a Nuclear Medicine Physician is crucial (differentiation benign/malignant lesions, artifacts…). A basic knowledge of MRI sequences is required, in such a way that geometrical distortions are easily recognized by all members the RT and RT physics team. If this is not the case, then the radiologist should be introduced systematically in the delineation process and multidisciplinary meetings need to be organized regularly. For each image modality and each image registration process, the associated uncertainties need to be determined and integrated in the PTV margin. When using functional information for dose painting, response assessment or outcome prediction, collaboration between the different departments is even more important. Limitations of imaging based biomarkers (specificity, sensitivity) should be known.


Assuntos
Imagem por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Garantia da Qualidade dos Cuidados de Saúde , Planejamento da Radioterapia Assistida por Computador/métodos , Incerteza , Artefatos , Humanos , Imagem por Ressonância Magnética/normas , Imagem Multimodal/normas , Estadiamento de Neoplasias , Neoplasias/patologia , Imagens de Fantasmas , Tomografia por Emissão de Pósitrons/métodos , Tomografia por Emissão de Pósitrons/normas , Tomografia Computadorizada por Raios X/métodos
6.
Cancer Radiother ; 23(6-7): 745-752, 2019 Oct.
Artigo em Francês | MEDLINE | ID: mdl-31439430

RESUMO

PET/CT has become a standard examination in oncology but is probably still underused for radiotherapy planning. However, except for the clinical research data that shows the interest of this examination in considering personalized and adaptive radiotherapy, it is also important in defining target volumes. However, before using it in clinical practice, a few prerequisites are required to know the acquisition and segmentation methods. Ideally, PET/CT should become a standard examination for radiotherapy departments in the same way as planning CT and tomorrow as MRI.


Assuntos
Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Radio-Oncologistas , Planejamento da Radioterapia Assistida por Computador/métodos , Humanos , Seleção de Pacientes , Medicina de Precisão , Resultado do Tratamento
7.
Cancer Radiother ; 23(6-7): 636-650, 2019 Oct.
Artigo em Francês | MEDLINE | ID: mdl-31444078

RESUMO

Liver stereotactic body radiotherapy is a developing technique for the treatment of primary tumours and metastases. Its implementation is complex because of the particularities of the treated organ and the comorbidities of the patients. However, this technique is a treatment opportunity for patients otherwise in therapeutic impasse. The scientific evidence of liver stereotactic body radiotherapy has been considered by the French health authority as insufficient for its widespread use outside specialized and experienced centers, despite a growing and important number of retrospective and prospective studies, but few comparative data. This article focuses on the specific features of stereotactic body radiotherapy for liver treatments and the results of published studies of liver stereotactic body radiotherapy performed with classic linear accelerators and dedicated radiosurgery units.


Assuntos
Carcinoma Hepatocelular/radioterapia , Neoplasias Hepáticas/radioterapia , Radiocirurgia/instrumentação , Carcinoma Hepatocelular/diagnóstico por imagem , Humanos , Fígado/efeitos da radiação , Cirrose Hepática/complicações , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Movimentos dos Órgãos , Aceleradores de Partículas , Guias de Prática Clínica como Assunto , Tolerância a Radiação , Radiocirurgia/métodos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Respiração , Resultado do Tratamento
8.
Br J Radiol ; 92(1103): 20190180, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31437023

RESUMO

The aim of this article is to propose meaningful guidance covering the practical and technical issues involved when planning or conducting clinical trials involving positron emission tomography (PET)-guided radiotherapy. The complexity of imaging requirements will depend on the study aims, design and PET methods used. Where PET is used to adapt radiotherapy, a high level of accuracy and reproducibility is required to ensure effective and safe treatment delivery. The guidance in this document is intended to assist researchers designing clinical trials involving PET-guided radiotherapy to provide sufficient information about the appropriate methods to complete PET-CT imaging to a consistent standard at participating centres. The guidance is divided into six categories: application of PET in radiotherapy, resource requirements, quality assurance, imaging protocol design, data management and image processing. Each section provides an overview of the recent literature to support the specific recommendations. This guidance builds on previous recommendations from the National Cancer Research Institute PET Research Network and has been produced in collaboration with the National Radiotherapy Trials Quality Assurance Group.


Assuntos
Ensaios Clínicos como Assunto/métodos , Neoplasias/radioterapia , Tomografia por Emissão de Pósitrons/métodos , Protocolos Clínicos , Ensaios Clínicos como Assunto/normas , Fluordesoxiglucose F18 , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/normas , Garantia da Qualidade dos Cuidados de Saúde , Compostos Radiofarmacêuticos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Carga Tumoral
9.
Medicine (Baltimore) ; 98(30): e16536, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31348271

RESUMO

This study aimed to analyze the influence of the radiation field size on the passing rate of the treatment planning system using MatriXX if the field irradiated the circuit.Two sets of static fields which were 10 cm and 30 cm in the left-right direction (X), and was 31 cm to 40 cm in gun-target direction (Y) were designed. In these fields, the gantry was 0 and the monitor units were 200 MU. Two plans from an esophagus carcinoma patient with a planning target volume of 86.4 cm and a cervical carcinoma patient with a planning target volume (PTV) of 2094.1 cm were chosen. The passing rates of these plans were gained without and with protecting the circuit area from lead alloys. The gamma analysis was used and the standard was set to 3%/3 mm.The verification passing rate decreased from 95.0% to 69.2% when X was 10 cm while Y increased from 31 cm to 40 cm. With the protection from low melting point lead alloys, the passing rate was from 96.2% to 89.6%. The results of the second set of plans without lead alloys were similar but the passing rate decreased more sharply. The passing rates of the 2 patients were 99.5% and 57.1%. With the protection of the lead alloys, their passing rates were 99.8% and 72.1%, respectively.The results showed that with the increase of the radiation field size in the Y direction, more areas were irradiated in the circuit, and the passing rate gradually decreases and dropped sharply at a certain threshold. After putting lead alloys above the circuit, the passing rate was much better in the static field but was still less than 90% in the second patient volumetric modulated arc therapy (VMAT) because the circuit was irradiate in other directions. In daily QA, we should pay attention to these patients with long size tumor.


Assuntos
Carcinoma/radioterapia , Neoplasias Esofágicas/radioterapia , Raios gama/uso terapêutico , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias do Colo do Útero/radioterapia , Feminino , Humanos , Masculino , Radiometria , Dosagem Radioterapêutica
10.
Cancer Radiother ; 23(5): 395-400, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31331842

RESUMO

PURPOSE: Lung and some digestive tumours move during a respiratory cycle. Four-dimensional scanography (4D-CT) is commonly used in treatment planning to account for respiratory motion. Although many French radiotherapy centres are now equipped, there are no guidelines on this subject to date. We wanted to draw up a description of the use of the 4D-CT for the treatment planning in France. METHODS AND MATERIAL: We conducted a survey in all French radiotherapy centres between March and April 2017. RESULTS: One hundred and seventy-two were contacted. The participation rate was 88.37%. The use of the 4D-CT seems to be common and concerned planning for 15.28% of kidney and adrenal cancers, 19.72% of pancreatic cancers, 27.78% of oesophageal cancers and 73.24% of lung cancers in case of normofractionated treatments. The use of the 4D-CT was also widespread in the case of stereotactic body radiation therapy: with 61.11% in the case of pulmonary irradiation and 34.72% in the case of hepatic irradiation. Many centres declared they carried out several 4D-CT for treatment planning (29, 55% in case of stereotactic body radiation therapy for lung tumours and 20% for liver tumours). Private centres tend to repeat 4D-CT more. CONCLUSION: Although the use of the 4D-CT appears to be developing, it remains very heterogeneous. To date, the repetition of the 4D-CT has been very poorly studied and could be the subject of clinical studies, allowing to define in which indications and for which populations there is a real benefit.


Assuntos
Tomografia Computadorizada Quadridimensional , Planejamento da Radioterapia Assistida por Computador/métodos , Artefatos , Institutos de Câncer/estatística & dados numéricos , França , Pesquisas sobre Serviços de Saúde , Hospitais Privados/estatística & dados numéricos , Hospitais Públicos/estatística & dados numéricos , Hospitais Universitários/estatística & dados numéricos , Humanos , Imagem Tridimensional/estatística & dados numéricos , Movimento (Física) , Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Utilização de Procedimentos e Técnicas , Serviço Hospitalar de Radiologia/estatística & dados numéricos , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/estatística & dados numéricos , Planejamento da Radioterapia Assistida por Computador/tendências , Respiração
11.
Clin Nucl Med ; 44(9): e510-e516, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31283600

RESUMO

To assess the role of Gallium-labeled-prostate-specific membrane antigen PET/CT (Ga-PSMA-PET/CT) in risk group definition and radiotherapy planning in the initially planned definitive radiotherapy (RT) for prostate cancer patients. METHODS: The clinical data of 191 prostate cancer patients treated with definitive intensity-modulated RT were retrospectively analyzed. All patients were initially staged with thoracoabdominal CT and bone scintigraphy, and the second staging was performed using Ga-PSMA-PET/CT. Both stages were evaluated for the decision making of RT and any change in RT target volumes. RESULTS: After staging with Ga-PSMA-PET/CT, 26 patients (13.6%) had risk group changes, 16 patients (8.4%) had an increase in risk group, and 10 patients (5.2%) had a decrease in risk group. Down-staging occurred in 22 patients (11.5%), and upstaging was observed in 30 patients (15.7%). A total of 26 patients (13.6%) had nodal stage changes. After the Ga-PSMA-PET/CT scans, the number of metastatic patient increased to 17 (8.9%), with 4 of them moving from oligo- to polymetastatic disease. An additional irradiation of pelvic lymphatics and metastatic site was performed in 13 patients (6.8%) and 6 patients (3.2%), respectively. The RT was aborted in 4 patients (2.1%) because of parenchymal or distant site metastasis observed in the Ga-PSMA-PET/CT. CONCLUSIONS: We found that Ga-PSMA-PET/CT causes considerable migration in stage, risk group, and RT field arrangements, especially in high-risk patients regardless of the GS and baseline prostate-specific antigen values alone. Ga-PSMA-PET/CT seems to have a great influence on RT decision making in prostate cancer patients.


Assuntos
Ácido Edético/análogos & derivados , Oligopeptídeos , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasias da Próstata/patologia , Radioterapia de Intensidade Modulada , Estudos Retrospectivos
12.
Br J Radiol ; 92(1100): 20190113, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31264474

RESUMO

OBJECTIVES: Re-irradiation of recurrent intracranial meningiomas represents a major challenge due to dose limits of critical structures and the necessity of sufficient dose coverage of the recurrent tumor for local control. The aim of this study was to investigate dosimetric differences between pencil beam scanning protons (PBS) and volumetric modulated arc therapy (VMAT) photons for intracranial re-irradiation of meningiomas. METHODS: Nine patients who received an initial dose >50 Gy for intracranial meningioma and who were re-irradiated for recurrence were selected for plan comparison. A volumetric modulated arc therapy photon and a pencil beam scanning proton plan were generated (prescription dose: 15 × 3 Gy) based on the targets used in the re-irradiation treatment. RESULTS: In all cases, where the cumulative dose exceeded 100 or 90 Gy, these high dose volumes were larger for the proton plans. The integral doses were significantly higher in all photon plans (reduction with protons: 48.6%, p < 0.01). In two cases (22.2%), organ at risk (OAR) sparing was superior with the proton plan. In one case (11.1%), the photon plan showed a dosimetric advantage. In the remaining six cases (66.7%), we found no clinically relevant differences in dose to the OARs. CONCLUSIONS: The dosimetric results of the accumulated dose for a re-irradiation with protons and with photons were very similar. The photon plans had a steeper dose falloff directly outside the target and were superior in minimizing the high dose volumes. The proton plans achieved a lower integral dose. Clinically relevant OAR sparing was extremely case specific. The optimal treatment modality should be assessed individually. ADVANCES IN KNOWLEDGE: Dose sparing in re-irradiation of intracranial meningiomas with protons or photons is highly case specific and the optimal treatment modality needs to be assessed on an individual basis.


Assuntos
Neoplasias Meníngeas/radioterapia , Meningioma/radioterapia , Recidiva Local de Neoplasia/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Reirradiação/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fótons , Terapia com Prótons , Prótons , Dosagem Radioterapêutica , Resultado do Tratamento
13.
Br J Radiol ; 92(1101): 20190150, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31265316

RESUMO

OBJECTIVE: To evaluate dose to organs at risk, target coverage and treatment compliance in left-sided breast cancer patients (LSBCP) treated with deep inspiration breath-hold (DIBH) and intensity modulated radiation therapy (IMRT) technique in a contest of daily clinical practice. METHODS: A total of 280 consecutive LSBCP referred for adjuvant radiotherapy were systematically screened for suitability of DIBH technique. 239 were able to comply with the requirement for DIBH. Whole breast or chest wall were irradiated in DIBH, monitored by Varian RPM™ Respiratory Gating System, and two tangential inverse-planned beams with dynamic dose delivery. Dose prescription was 42.4 Gy/16 fractions in 205 patients and 50 Gy/25 fractions in 34. 23 patients received local and nodal treatment. Boost to tumor bed, of 10 Gy/5 fractions was used in 135 patients. Relevant dose metrics for heart, left anterior descending (LAD) coronary artery, lungs, contralateral breast and planning target volume were retrospectively analyzed. RESULTS: The average mean heart dose (MHD) for all patients was 0.94 Gy and mean maximum LAD dose was 13.82 Gy. MHD and LAD maximum dose were significantly higher in patients treated with conventional fractionation whether expressed in absolute dose (1.44 vs 0.85 Gy, p < 0.0005 and 20.78 vs 12.45 Gy, p < 0.0005 respectively) or in equivalent doses of 2 Gy fractionation (0.88 vs 0.52 Gy, p =< 0.0005 and 17.68 vs 10.63 Gy, p = 0.0002 respectively). In 57 patients (23.8%) the maximum LAD dose was >20 Gy. Mean V20 ipsilateral lung dose was 8.5%. Mean doses of contralateral breast and lung were 0.13 Gy and 0.09 Gy respectively. Mean planning target volume V95% coverage was 96.1%. Compliance rate of DIBH technique was 84.5% (239/280). CONCLUSION: DIBH and IMRT in daily clinical practice are feasible in high percentage of unselected patients and allows low levels of irradiation of organs at risk without compromising target coverage. However, despite low MHD a significant proportion of patients receives a maximum LAD dose superior to 20 Gy. ADVANCES IN KNOWLEDGE: The value of MHD used exclusively is not able to describe entirely the risk of late heart toxicity, which can be better evaluated with the joint analysis of the maximum dose to LAD region. The vast majority of LSBCP referred to adjuvant radiotherapy in the setting of routine practice are able to comply with the requirement of DIBH.


Assuntos
Neoplasias da Mama/radioterapia , Suspensão da Respiração , Órgãos em Risco/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Adulto , Idoso , Mama/efeitos da radiação , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Estudos Retrospectivos
14.
Br J Radiol ; 92(1101): 20190184, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31287737

RESUMO

OBJECTIVES: In non-small cell lung cancer (NSCLC) patients, to establish whether the fractional volumes of irradiated anatomic or perfused lung differed between those with and without deteriorating lung function or radiation associated lung injury (RALI). METHODS: 48 patients undergoing radical radiotherapy for NSCLC had a radiotherapy-planning CT scan and single photon emission CT lung perfusion imaging (99mTc-labelled macroaggregate albumin). CT defined the anatomic and the single photon emission CT scan (co-registered with CT) identified the perfused (threshold 20 % of maximum) lung volumes. Fractional volumes of anatomic and perfused lung receiving more than 5, 10, 13, 20, 30, 40, 50 Gy were compared between patients with deteriorating (>median decline) vs stable (30, 40, 50 Gy). Fractional volumes of anatomic and perfused lung receiving > 10 Gy best predicted decline in FEV1 (Area under receiver operating characteristic curve (Az = 0.77 and 0.76 respectively); sensitivity/specificity 75%/81 and 80%/71%) for a 32.7% anatomic and 33.5% perfused volume cut-off. Irradiating an anatomic fractional volume of 4.7% to > 50 Gy had a sensitivity/specificity of 83%/89 % for indicating RALI (Az = 0.83). CONCLUSION: A 10-20 Gy radiation dose to anatomic or perfused lung results in decline in FEV1. A fractional anatomic volume of >5% receiving >50 Gy influences development of RALI. ADVANCES IN KNOWLEDGE: Extent of low-dose radiation to normal lung influences functional respiratory decline.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Lesões por Radiação/diagnóstico por imagem , Planejamento da Radioterapia Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Feminino , Humanos , Pulmão/diagnóstico por imagem , Pulmão/efeitos da radiação , Neoplasias Pulmonares/radioterapia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Dosagem Radioterapêutica , Tomografia Computadorizada de Emissão de Fóton Único/métodos
15.
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
16.
Br J Radiol ; 92(1102): 20190317, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31295011

RESUMO

OBJECTIVE: In this study, we used the concept of organ-equivalent dose (OED) to evaluate the excess absolute risk (EAR) for secondary cancer in various organs after radiation treatment for breast cancer. METHODS: Using CT data set of 12 patients, we generated three different whole-breast radiation treatment plans using 50 Gy in 2 Gy fractions: three-dimensional conformal radiotherapy with a field-in-field (FinF) technique, intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). The OEDs were calculated from differential dose-volume histograms on the basis of the "linear-exponential," "plateau," and "full mechanistic" dose-response models. Secondary cancer risks of the contralateral breast (CB), contralateral lung (CL), and ipsilateral lung (IL) were estimated and compared. RESULTS: The lowest EARs for the CB, CL, and IL were achieved with FinF, which reduced the EARs by 77%, 88%, and 56% relative to those with IMRT, and by 77%, 84%, and 58% relative to those with VMAT, respectively. The secondary cancer risk for FinF was significantly lower than those of IMRT and VMAT. OED-based secondary cancer risks for CB and IL were similar when IMRT and VMAT were used, but the risk for CL was statistically lower when VMAT was used. CONCLUSION: The overall estimation of EAR indicated that the radiation-induced cancer risk of breast radiation therapy was lower with FinF than with IMRT and VMAT. Therefore, when secondary cancer risk is a major concern, FinF is considered to be the preferred treatment option in irradiation of whole-breast. ADVANCES IN KNOWLEDGE: Secondary malignancy estimation after breast radiotherapy is becoming an important subject for comparative treatment planning.When secondary cancer risk a major concern, FinF technique is considered the preferred treatment option in whole breast patients.


Assuntos
Neoplasias da Mama/radioterapia , Neoplasias Induzidas por Radiação/etiologia , Segunda Neoplasia Primária/etiologia , Radioterapia Conformacional/efeitos adversos , Radioterapia de Intensidade Modulada/efeitos adversos , Mama/diagnóstico por imagem , Mama/efeitos da radiação , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Feminino , Coração/diagnóstico por imagem , Coração/efeitos da radiação , Humanos , Pulmão/diagnóstico por imagem , Pulmão/efeitos da radiação , Neoplasias Pulmonares/etiologia , Números Necessários para Tratar , Órgãos em Risco/diagnóstico por imagem , Órgãos em Risco/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos , Medição de Risco/métodos , Tomografia Computadorizada por Raios X , Neoplasias Unilaterais da Mama/etiologia
17.
Medicine (Baltimore) ; 98(24): e15938, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31192929

RESUMO

The aim of this study was to investigate the dose optimization strategy for the sacrum to reduce the risk of pelvic insufficiency fracture (PIF).Using a retrospective study design, we analyzed data from 28 patients with cervical cancer who underwent postoperative adjuvant radiotherapy in our department from June 2017 to January 2018. Among these patients, 20 (71.4%) underwent external beam radiation therapy in the pelvic lymphatic drainage area (node-negative patients). Overall, 8 patients (28.6%) underwent radiotherapy in the pelvic lymphatic drainage area with a simultaneous integrated boost (node-positive patients). Furthermore, 20 patients were assigned to 2 groups of plans according to the prescribed doses of 5000 and 4500 cGy/25. Each group had 3 plans according to 3 different dose limit conditions: "pelvic bones and sacrum unlimited," "pelvic bones limited," and "pelvic bones + sacrum limited." The irradiation dose of the sacrum and pelvis was analyzed in three limited optimization models.The planning target volume conformity index and homogeneity index, based on different optimization modes in the 4500 and 5000 cGy plans, showed no significant differences. The D50% and Dmean of the pelvis + sacrum limited mode were significantly lower than those of the pelvic limited mode (P < .001). The dose of the sacrum and pelvis in the 4500 cGy plan in the lymphatic drainage area was significantly lower than that of the 5000 cGy plan (P < .001). In the lymph node boost group, the irradiation dose of the sacrum and pelvis was significantly increased (P ≤ .001).Increasing the limitation of the sacrum, on the basis of pelvic bone limitation, in cervical cancer intensity-modulated radiation therapy can significantly reduce the dose to the sacrum. Compared with the dose of 5000 cGy to the lymphatic drainage area, the dose of 4500 cGy was the largest influencing factor to reduce the dose to the sacrum.


Assuntos
Pelve/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Sacro/efeitos da radiação , Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pessoa de Meia-Idade , Doses de Radiação , Dosagem Radioterapêutica , Radioterapia Adjuvante , Estudos Retrospectivos , Resultado do Tratamento
18.
Anticancer Res ; 39(6): 3015-3024, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31177143

RESUMO

AIM: To compare the advantage of image-guided brachytherapy (IGBT) over conventional two-dimensional brachytherapy (2DBT) in patients with advanced cervical squamous cell carcinoma. PATIENTS AND METHODS: This study included 253 patients with stage IB2-IVA diseases treated with two schemes of brachytherapy. One hundred and thirty-six patients received 2DBT, whereas 117 patients received IGBT. Tumor stage, age, and tumor diameter were matched between the two groups. Local relapse-free survival, overall survival, and cumulative incidences of gastrointestinal and genitourinary complications were compared between the two groups. RESULTS: The overall and local relapse-free survival rates were similar between the two groups. The cumulative rate of grade 2 and higher gastrointestinal complication was 21.3% for the 2DBT group, and 8.5% for the IGBT group (p=0.007), whereas that of grade 2 and higher genitourinary injury was 11.8% for the 2DBT group, and 1.7% for the IGBT group (p=0.002). CONCLUSION: In patients with advanced cervical squamous cell carcinoma, IGBT achieves a higher therapeutic ratio compared to 2DBT technique by minimizing the late toxicities.


Assuntos
Braquiterapia/métodos , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Tomografia Computadorizada por Raios X , Neoplasias do Colo do Útero/terapia , Adulto , Idoso , Antineoplásicos/administração & dosagem , Braquiterapia/efeitos adversos , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Quimiorradioterapia/efeitos adversos , Cisplatino/administração & dosagem , Fracionamento da Dose de Radiação , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Intervalo Livre de Progressão , Estudos Retrospectivos , Fatores de Tempo , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/patologia
19.
Br J Radiol ; 92(1100): 20190067, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31192695

RESUMO

OBJECTIVE: The purpose of this work is to develop and validate a learning-based method to derive electron density from routine anatomical MRI for potential MRI-based SBRT treatment planning. METHODS: We proposed to integrate dense block into cycle generative adversarial network (GAN) to effectively capture the relationship between the CT and MRI for CT synthesis. A cohort of 21 patients with co-registered CT and MR pairs were used to evaluate our proposed method by the leave-one-out cross-validation. Mean absolute error, peak signal-to-noise ratio and normalized cross-correlation were used to quantify the imaging differences between the synthetic CT (sCT) and CT. The accuracy of Hounsfield unit (HU) values in sCT for dose calculation was evaluated by comparing the dose distribution in sCT-based and CT-based treatment planning. Clinically relevant dose-volume histogram metrics were then extracted from the sCT-based and CT-based plans for quantitative comparison. RESULTS: The mean absolute error, peak signal-to-noise ratio and normalized cross-correlation of the sCT were 72.87 ± 18.16 HU, 22.65 ± 3.63 dB and 0.92 ± 0.04, respectively. No significant differences were observed in the majority of the planning target volume and organ at risk dose-volume histogram metrics ( p > 0.05). The average pass rate of γ analysis was over 99% with 1%/1 mm acceptance criteria on the coronal plane that intersects with isocenter. CONCLUSION: The image similarity and dosimetric agreement between sCT and original CT warrant further development of an MRI-only workflow for liver stereotactic body radiation therapy. ADVANCES IN KNOWLEDGE: This work is the first deep-learning-based approach to generating abdominal sCT through dense-cycle-GAN. This method can successfully generate the small bony structures such as the rib bones and is able to predict the HU values for dose calculation with comparable accuracy to reference CT images.


Assuntos
Carcinoma Hepatocelular/radioterapia , Neoplasias Hepáticas/radioterapia , Imagem por Ressonância Magnética/métodos , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Carcinoma Hepatocelular/diagnóstico por imagem , Aprendizado Profundo , Humanos , Fígado/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Radioterapia de Intensidade Modulada/métodos
20.
Br J Radiol ; 92(1100): 20190004, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31188018

RESUMO

OBJECTIVE: To evaluate and compare the dosimetric plan quality for noncoplanar volumetric arc therapy of single and multiple brain metastases using the linear accelerator-based radiosurgery system HyperArc and a robotic radiosurgery system. METHODS: 31 tumors from 24 patients were treated by stereotactic radiosurgery using the CyberKnife system. CT images, structure sets, and dose files were transferred to the Eclipse treatment planning system for the HyperArc system. Dosimetric parameters for both plans were compared. The beam-on time was calculated from the total monitor unit and dose rate. RESULTS: For normal brain tissue, the received volume doses were significantly lower for HyperArc than for CyberKnife_G4 and strongly correlated with the planning target volume (PTV) for cases of single brain metastasis. In addition, the difference in volume dose between CyberKnife_G4 and HyperArc was proportional to the PTV. For multiple brain metastases, no significant difference was observed between the two stereotactic radiosurgery systems, except for high-dose region in the normal tissue. In low dose for brain minus PTV, when the maximum distance among each target was above 8.0 cm, HyperArc delivered higher dose than CyberKnife_G4. The mean ± SDs for the beam-on time were 15.8 ± 5.3 and 5.6 ± 0.8 min for CyberKnife_G4 and HyperArc, respectively (p < .01). CONCLUSION: HyperArc is best suited for larger targets in single brain metastasis and for smaller inter tumor tumor distances in multiple brain metastases. ADVANCES IN KNOWLEDGE: The performance of HyperArc in comparison with CyberKnife_G4 was depended on defined margin and tumor distances.


Assuntos
Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Encéfalo/efeitos da radiação , Encéfalo/cirurgia , Feminino , Humanos , Masculino , Radiometria , Dosagem Radioterapêutica , Resultado do Tratamento
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