RESUMEN
BACKGROUND: To evaluate potential synergistic effect of pembrolizumab with radiotherapy (RT) compared with a standard-of-care (SOC) cetuximab-RT in patients with locally advanced-squamous cell carcinoma of head and neck (LA-SCCHN). PATIENTS AND METHODS: Patients with nonoperated stage III-IV SCC of oral cavity, oropharynx, hypopharynx, and larynx and unfit for receiving high-dose cisplatin were enrolled. Patients received once-daily RT up to 69.96 Gy in 33 fractions with weekly cetuximab (cetuximab-RT arm) or 200 mg Q3W pembrolizumab during RT (pembrolizumab-RT arm). The primary endpoint was locoregional control (LRC) rate 15 months after RT. To detect a difference between arms of 60%-80% in 15-month LRC, inclusion of 66 patients per arm was required to achieve a power of at least 0.85 at two-sided significance level of 0.20. RESULTS: Between May 2016 and October 2017, 133 patients were randomized to cetuximab-RT (n = 66) and pembrolizumab-RT (n = 67). Two patients (one in each arm) were not included in the analysis (a consent withdrawal and a progression before treatment start). The median age was 65 years (interquartile range 60-70 years), 92% were smokers, 60% were oropharynx (46% of oropharynx with p16+) and 75% were stage IV. Median follow-up was 25 months in both arms. The 15-month LRC rate was 59% with cetuximab-RT and 60% with pembrolizumab-RT ]odds ratio 1.05, 95% confidence interval (CI) 0.43-2.59; P = 0.91]. There was no significant difference between arms for progression-free survival (hazard ratio 0.85, 95% CI 0.55-1.32; P = 0.47) and for overall survival (hazard ratio 0.83, 95% CI 0.49-1.40; P = 0.49). Toxicity was lower in the pembrolizumab-RT arm than in the cetuximab-RT arm: 74% versus 92% patients with at least one grade ≥3 adverse events (P = 0.006), mainly due to mucositis, radiodermatitis, and rash. CONCLUSION: Compared with the SOC cetuximab-RT, pembrolizumab concomitant with RT did not improve the tumor control and survival but appeared less toxic in unfit patients with LA-SCCHN.
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Quimioradioterapia , Neoplasias de Cabeza y Cuello , Carcinoma de Células Escamosas de Cabeza y Cuello , Anciano , Humanos , Persona de Mediana Edad , Cetuximab/uso terapéutico , Quimioradioterapia/efectos adversos , Cisplatino/uso terapéutico , Neoplasias de Cabeza y Cuello/terapia , Carcinoma de Células Escamosas de Cabeza y Cuello/terapiaRESUMEN
BACKGROUND: Targeting the programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) axis has demonstrated clinical benefit in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC). Combining immunotherapies targeting PD-L1 and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) has shown evidence of additive activity in several tumor types. This phase III study evaluated the efficacy of durvalumab (an anti-PD-L1 monoclonal antibody) or durvalumab plus tremelimumab (an anti-CTLA-4 monoclonal antibody) versus standard of care (SoC) in R/M HNSCC patients. PATIENTS AND METHODS: Patients were randomly assigned to receive 1 : 1 : 1 durvalumab (10 mg/kg every 2 weeks [q2w]), durvalumab plus tremelimumab (durvalumab 20 mg/kg q4w plus tremelimumab 1 mg/kg q4w × 4, then durvalumab 10 mg/kg q2w), or SoC (cetuximab, a taxane, methotrexate, or a fluoropyrimidine). The primary end points were overall survival (OS) for durvalumab versus SoC, and OS for durvalumab plus tremelimumab versus SoC. Secondary end points included progression-free survival (PFS), objective response rate, and duration of response. RESULTS: Patients were randomly assigned to receive durvalumab (n = 240), durvalumab plus tremelimumab (n = 247), or SoC (n = 249). No statistically significant improvements in OS were observed for durvalumab versus SoC [hazard ratio (HR): 0.88; 95% confidence interval (CI): 0.72-1.08; P = 0.20] or durvalumab plus tremelimumab versus SoC (HR: 1.04; 95% CI: 0.85-1.26; P = 0.76). The 12-month survival rates (95% CI) were 37.0% (30.9-43.1), 30.4% (24.7-36.3), and 30.5% (24.7-36.4) for durvalumab, durvalumab plus tremelimumab, and SoC, respectively. Treatment-related adverse events (trAEs) were consistent with previous reports. The most common trAEs (any grade) were hypothyroidism for durvalumab and durvalumab plus tremelimumab (11.4% and 12.2%, respectively), and anemia (17.5%) for SoC. Grade ≥3 trAE rates were 10.1%, 16.3%, and 24.2% for durvalumab, durvalumab plus tremelimumab, and SoC, respectively. CONCLUSION: There were no statistically significant differences in OS for durvalumab or durvalumab plus tremelimumab versus SoC. However, higher survival rates at 12 to 24 months and response rates demonstrate clinical activity for durvalumab. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02369874.
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Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias de Cabeza y Cuello , Anticuerpos Monoclonales , Anticuerpos Monoclonales Humanizados/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Humanos , Recurrencia Local de Neoplasia/tratamiento farmacológico , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológicoRESUMEN
BACKGROUND AND PURPOSE: During head-and-neck (H&N) radiotherapy, the parotid glands (PGs) may be overdosed; thus, a tool is required to monitor the delivered dose. This study aimed to assess the dose accuracy of a patient-specific density assignment method (DAM) for dose calculation to monitor the dose to PGs during treatment. PATIENTS AND METHODS: Forty patients with H&N cancer received an intensity modulated radiation therapy (IMRT), among whom 15 had weekly CTs. Dose distributions were calculated either on the CTs (CTref), on one-class CTs (1C-CT, water), or on three-class CTs (3C-CT, water-air-bone). The inter- and intra-patient DAM uncertainties were evaluated by the difference between doses calculated on CTref and 1C-CTs or 3C-CTs. PG mean dose (Dmean) and spinal cord maximum dose (D2%) were considered. The cumulated dose to the PGs was estimated by the mean Dmean of the weekly CTs. RESULTS: The mean (maximum) inter-patient DAM dose uncertainties for the PGs (in cGy) were 23 (75) using 1C-CTs and 12 (50) using 3C-CTs (pâ¯≤ 0.001). For the spinal cord, these uncertainties were 118 (245) and 15 (67; pâ¯≤ 0.001). The mean (maximum) DAM dose uncertainty between cumulated doses calculated on CTs and 3C-CTs was 7 cGy (45 cGy) for the PGs. Considering the difference between the planned and cumulated doses, 53% of the ipsilateral and 80% of the contralateral PGs were overdosed by +3.6â¯Gy (up to 8.2â¯Gy) and +1.9â¯Gy (up to 5.2â¯Gy), respectively. CONCLUSION: The uncertainty of the three-class DAM appears to be clinically non-significant (<0.5â¯Gy) compared with the PG overdose (up to 8.2â¯Gy). This DAM could therefore be used to monitor PG doses and trigger replanning.
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Neoplasias Orofaríngeas/radioterapia , Glándula Parótida/efectos de la radiación , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Orofaríngeas/diagnóstico por imagen , Neoplasias Orofaríngeas/patología , Glándula Parótida/diagnóstico por imagen , Radiometría , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos , IncertidumbreRESUMEN
INTRODUCTION: Large anatomical variations can be observed during the treatment course intensity-modulated radiotherapy (IMRT) for head and neck cancer (HNC), leading to potential dose variations. Adaptive radiotherapy (ART) uses one or several replanning sessions to correct these variations and thus optimize the delivered dose distribution to the daily anatomy of the patient. This review, which is focused on ART in the HNC, aims to identify the various strategies of ART and to estimate the dosimetric and clinical benefits of these strategies. MATERIAL AND METHODS: We performed an electronic search of articles published in PubMed/MEDLINE and Science Direct from January 2005 to December 2016. Among a total of 134 articles assessed for eligibility, 29 articles were ultimately retained for the review. Eighteen studies evaluated dosimetric variations without ART, and 11 studies reported the benefits of ART. RESULTS: Eight in silico studies tested a number of replanning sessions, ranging from 1 to 6, aiming primarily to reduce the dose to the parotid glands. The optimal timing for replanning appears to be early during the first two weeks of treatment. Compared to standard IMRT, ART decreases the mean dose to the parotid gland from 0.6 to 6 Gy and the maximum dose to the spinal cord from 0.1 to 4 Gy while improving target coverage and homogeneity in most studies. Only five studies reported the clinical results of ART, and three of those studies included a non-randomized comparison with standard IMRT. These studies suggest a benefit of ART in regard to decreasing xerostomia, increasing quality of life, and increasing local control. Patients with the largest early anatomical and dose variations are the best candidates for ART. CONCLUSION: ART may decrease toxicity and improve local control for locally advanced HNC. However, randomized trials are necessary to demonstrate the benefit of ART before using the technique in routine practice.
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Neoplasias de Cabeza y Cuello/radioterapia , Planificación de la Radioterapia Asistida por Computador/métodos , Neoplasias de Cabeza y Cuello/mortalidad , Humanos , Órganos en Riesgo , Glándula Parótida/efectos de la radiación , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada , Médula Espinal/efectos de la radiaciónRESUMEN
BACKGROUND: In 2008, a study of the characteristics of hospitalised patients led to the development of a prognostic tool that distinguished three populations with significantly different 2-month survival rates. The goal of our study aimed at validating prospectively this prognostic tool in outpatients treated for cancer in terminal stage, based on four factors: performance status (ECOG) (PS), number of metastatic sites, serum albumin and lactate dehydrogenase. PATIENTS AND METHODS: PRONOPALL is a multicentre study of current care. About 302 adult patients who met one or more of the following criteria: life expectancy under 6 months, performance status ≥ 2 and disease progression during the previous chemotherapy regimen were included across 16 institutions between October 2009 and October 2010. Afterwards, in order to validate the prognostic tool, the score was ciphered and correlated to patient survival. RESULTS: Totally 262 patients (87%) were evaluable (27 patients excluded and 13 unknown score). Median age was 66 years [37-88], and women accounted for 59%. ECOG PS 0-1 (46%), PS 2 (37%) and PS 3-4 (17%). The primary tumours were: breast (29%), colorectal (28%), lung (13%), pancreas (12%), ovary (11%) and other (8%). About 32% of patients presented one metastatic site, 35% had two and 31% had more than two. The median lactate dehydrogenase level was 398 IU/l [118-4314]; median serum albumin was 35 g/l [13-54]. According to the PRONOPALL prognostic tool, the 2-month survival rate was 92% and the median survival rate was 301 days [209-348] for the 130 patients in population C, 66% and 79 days [71-114] for the 111 patients in population B, and 24% and 35 days for [14-56] the 21 patients in population A. These three populations survival were statistically different (P <0.0001). CONCLUSION: PRONOPALL study confirms the three prognostic profiles defined by the combination of four factors. This PRONOPALL score is a useful decision-making tool in daily practice.
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Atención Ambulatoria , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Técnicas de Apoyo para la Decisión , Neoplasias/tratamiento farmacológico , Cuidados Paliativos , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/sangre , Progresión de la Enfermedad , Femenino , Francia , Humanos , Estimación de Kaplan-Meier , L-Lactato Deshidrogenasa/sangre , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Neoplasias/sangre , Neoplasias/mortalidad , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Reproducibilidad de los Resultados , Factores de Riesgo , Albúmina Sérica Humana/análisis , Factores de Tiempo , Resultado del TratamientoRESUMEN
Obstructive sleep apnea (OSA) is characterised by repetitive cessation or reduction of airflow due to upper airway obstructions. These respiratory events lead to chronic sleep fragmentation and intermittent hypoxemia. Several studies have shown that OSA is associated with daytime sleepiness and cognitive dysfunctions, characterized by impairments of attention, episodic memory, working memory, and executive functions. This paper reviews the cognitive profile of adults with OSA and discusses the relative role of altered sleep and hypoxemia in the aetiology of these cognitive deficits. Markers of cognitive dysfunctions such as those measured with waking electroencephalography and neuroimaging are also presented. The effects of continuous positive airway pressure (CPAP) on cognitive functioning and the possibility of permanent brain damage associated with OSA are also discussed. Finally, this paper reviews the evidence suggesting that OSA is a risk factor for developing mild cognitive impairment and dementia in the aging population and stresses the importance of its early diagnosis and treatment.
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Trastornos del Conocimiento/etiología , Apnea Obstructiva del Sueño/psicología , Adulto , Anciano , Atención/fisiología , Daño Encefálico Crónico/etiología , Daño Encefálico Crónico/fisiopatología , Daño Encefálico Crónico/prevención & control , Trastornos del Conocimiento/fisiopatología , Trastornos del Conocimiento/prevención & control , Comorbilidad , Presión de las Vías Aéreas Positiva Contínua , Demencia/etiología , Demencia/fisiopatología , Demencia/prevención & control , Trastornos de Somnolencia Excesiva/etiología , Trastornos de Somnolencia Excesiva/prevención & control , Electroencefalografía , Potenciales Evocados , Función Ejecutiva/fisiología , Femenino , Humanos , Hipoxia/etiología , Hipoxia/prevención & control , Masculino , Trastornos de la Memoria/etiología , Trastornos de la Memoria/fisiopatología , Trastornos de la Memoria/prevención & control , Persona de Mediana Edad , Neuroimagen , Desempeño Psicomotor/fisiología , Factores de Riesgo , Apnea Obstructiva del Sueño/complicaciones , Apnea Obstructiva del Sueño/diagnóstico , Apnea Obstructiva del Sueño/epidemiología , Apnea Obstructiva del Sueño/fisiopatología , Apnea Obstructiva del Sueño/terapia , Privación de Sueño/etiología , Privación de Sueño/psicología , Ronquido/etiologíaRESUMEN
PURPOSE: The increased risk of second cancer after prostate radiotherapy is a debated clinical concern. The objective of the study was to assess the risk of occurrence of second cancers after prostate radiation therapy based on the analysis the literature, and to identify potential factors explaining the discrepancies in results between studies. MATERIALS AND METHODS: A review of the literature was carried out, comparing the occurrence of second cancers in patients all presenting with prostate cancer, treated or not by radiation. RESULTS: This review included 30 studies reporting the occurrence of second cancers in 2,112,000 patients treated or monitored for localized prostate cancer, including 1,111,000 by external radiation therapy and 103,000 by brachytherapy. Regarding external radiation therapy, the average follow-up was 7.3years. The majority of studies (80%) involving external radiation therapy, compared to no external radiation therapy, showed an increased risk of second cancers with a hazard ratio ranging from 1.13 to 4.9, depending on the duration of the follow-up. The median time to the occurrence of these second cancers after external radiotherapy ranged from 4 to 6years. An increased risk of second rectal and bladder cancer was observed in 52% and 85% of the studies, respectively. Considering a censoring period of more than 10 years after irradiation, 57% and 100% of the studies found an increased risk of rectal and bladder cancer, without any impact in overall survival. Studies of brachytherapy did not show an increased risk of second cancer. However, these comparative studies, most often old and retrospective, had many methodological biases. CONCLUSION: Despite numerous methodological biases, prostate external radiation therapy appears associated with a moderate increase in the risk of second pelvic cancer, in particular bladder cancer, without impacting survival. Brachytherapy does not increase the risk of a second cancer.
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Braquiterapia , Neoplasias Inducidas por Radiación , Neoplasias Primarias Secundarias , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/radioterapia , Neoplasias Primarias Secundarias/etiología , Neoplasias Primarias Secundarias/epidemiología , Neoplasias Inducidas por Radiación/etiología , Neoplasias Inducidas por Radiación/epidemiología , Braquiterapia/efectos adversos , Braquiterapia/métodos , Neoplasias de la Vejiga Urinaria/radioterapia , Neoplasias de la Vejiga Urinaria/etiología , Neoplasias del Recto/radioterapia , Neoplasias del Recto/etiologíaAsunto(s)
Neoplasias de Cabeza y Cuello/radioterapia , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia Guiada por Imagen/métodos , Radioterapia de Intensidad Modulada/métodos , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/radioterapia , Relación Dosis-Respuesta en la Radiación , Neoplasias de Cabeza y Cuello/patología , Humanos , Neoplasias Orofaríngeas/patología , Neoplasias Orofaríngeas/radioterapia , Medicina de Precisión/métodos , Dosificación Radioterapéutica , Carga Tumoral/efectos de la radiaciónRESUMEN
We present the updated recommendations of the French society for oncological radiotherapy on image-guided radiotherapy (IGRT). The objective of the IGRT is to take into account the anatomical variations of the target volume occurring between or during the irradiation fractions, such as displacements and/or deformations, so that the delivered dose corresponds to the planned dose. This article presents the different IGRT devices, their use and quality control, and quantify the possible additional dose generated by each of them. The practical implementation of IGRT in various tumour locations is summarised, from the different "RecoRad™" guideline articles. Adaptive radiotherapy is then detailed, due to its complexity and its probable development in the next years. The place of radiation technologist in the practice of IGRT is then specified. Finally, a brief update is proposed on the delicate question of the additional dose linked to the in-room imaging, which must be estimated and documented at a minimum, as long as it is difficult to integrate it into the calculation of the dose distribution.
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Neoplasias/radioterapia , Posicionamiento del Paciente , Radioterapia Guiada por Imagen/normas , Francia , Humanos , Neoplasias/diagnóstico por imagen , Traumatismos por Radiación/prevención & control , Oncología por Radiación , Dosificación Radioterapéutica , Radioterapia Guiada por Imagen/instrumentación , Radioterapia Guiada por Imagen/métodos , Sociedades MédicasRESUMEN
Primary vaginal cancers are rare tumours, for which external beam radiotherapy and brachytherapy are major treatment tools. Given the complexity of brachytherapy techniques, the treatment should be performed in specialised centres. We present the recommendations of the French society for radiation oncology on the indications and techniques for external beam radiotherapy and brachytherapy for primary vaginal cancer.
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Carcinoma de Células Escamosas/radioterapia , Neoplasias Vaginales/radioterapia , Braquiterapia/métodos , Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/patología , Femenino , Francia , Humanos , Oncología por Radiación , Enfermedades Raras/diagnóstico por imagen , Enfermedades Raras/patología , Enfermedades Raras/radioterapia , Estudios Retrospectivos , Neoplasias Vaginales/diagnóstico por imagen , Neoplasias Vaginales/patologíaRESUMEN
External beam radiotherapy and brachytherapy are major treatments in the management of cervical cancer. For early-stage tumours with local risk factors, brachytherapy is a preoperative option. Postoperative radiotherapy is indicated according to histopathological criteria. For advanced local tumours, chemoradiation is the standard treatment, followed by brachytherapy boost, which is not optional. We present the update of the recommendations of the French Society of Oncological Radiotherapy on the indications and techniques for external beam radiotherapy and brachytherapy for cervical cancer.
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Neoplasias del Cuello Uterino/radioterapia , Braquiterapia/métodos , Quimioradioterapia , Quimioterapia Adyuvante , Femenino , Francia , Humanos , Estadificación de Neoplasias/clasificación , Órganos en Riesgo/diagnóstico por imagen , Posicionamiento del Paciente , Cuidados Posoperatorios , Cuidados Preoperatorios/métodos , Oncología por Radiación , Terapia Recuperativa , Carga Tumoral , Neoplasias del Cuello Uterino/diagnóstico por imagen , Neoplasias del Cuello Uterino/patología , Neoplasias del Cuello Uterino/terapiaRESUMEN
The first intent upfront treatment of endometrial cancer is surgery. External radiotherapy and brachytherapy; however, are important tools in adjuvant setting, according to histopathological risk factors for locoregional recurrence or in the event of an inoperable tumor. We present the update of the recommendations of the French society of oncological radiotherapy on the indications and technical methods of performing radiotherapy and brachytherapy for endometrial cancer.
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Neoplasias Endometriales/radioterapia , Braquiterapia/métodos , Neoplasias Endometriales/patología , Femenino , Francia , Humanos , Estadificación de Neoplasias , Cuidados Posoperatorios , Oncología por Radiación , Radioterapia Adyuvante/métodos , Carga TumoralRESUMEN
Primary vulvar carcinomas are rare gynaecological cancers, for which surgery is the mainstay of treatment. There is however a major place for external beam radiotherapy in the situation of inoperable locally advanced tumours and/or as adjuvant therapy, when there are risk factors for locoregional relapse. We present the recommendations of the French society for radiation oncology on the indications and techniques for radiotherapy in the treatment of primary vulvar cancer.
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Carcinoma de Células Escamosas/radioterapia , Neoplasias de la Vulva/radioterapia , Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/cirugía , Femenino , Francia , Humanos , Escisión del Ganglio Linfático , Irradiación Linfática , Márgenes de Escisión , Posicionamiento del Paciente/métodos , Oncología por Radiación , Dosificación Radioterapéutica , Radioterapia Adyuvante/métodos , Enfermedades Raras/diagnóstico por imagen , Enfermedades Raras/patología , Enfermedades Raras/radioterapia , Enfermedades Raras/cirugía , Carga Tumoral , Vulva/cirugía , Neoplasias de la Vulva/diagnóstico por imagen , Neoplasias de la Vulva/cirugía , Neoplasias de la Vulva/terapiaRESUMEN
PURPOSE: The first aim was to generate and compare synthetic-CT (sCT) images using a conditional generative adversarial network (cGAN) method (Pix2Pix) for MRI-only prostate radiotherapy planning by testing several generators, loss functions, and hyper-parameters. The second aim was to compare the optimized Pix2Pix model with five other architectures (bulk-density, atlas-based, patch-based, U-Net, and GAN). METHODS: For 39 patients treated by VMAT for prostate cancer, T2-weighted MRI images were acquired in addition to CT images for treatment planning. sCT images were generated using the Pix2Pix model. The generator, loss function, and hyper-parameters were tuned to improve sCT image generation (in terms of imaging endpoints). The final evaluation was performed by 3-fold cross-validation. This method was compared to five other methods using the following imaging endpoints: the mean absolute error (MAE) and mean error (ME) between sCT and reference CT images (rCT) of the whole pelvis, bones, prostate, bladder, and rectum. For dose planning analysis, the dose-volume histogram metric differences and 3D gamma analysis (local, 1 %/1 mm) were calculated using the sCT and reference CT images. RESULTS: Compared with the other architectures, Pix2Pix with Perceptual loss function and generator ResNet 9 blocks showed the lowest MAE (29.5, 107.7, 16.0, 13.4, and 49.1 HU for the whole pelvis, bones, prostate, bladder, and rectum, respectively) and the highest gamma passing rates (99.4 %, using the 1 %/1mm and 10 % dose threshold criterion). Concerning the DVH points, the mean errors were -0.2% for the planning target volume V95%, 0.1 % for the rectum V70Gy, and -0.1 % for the bladder V50Gy. CONCLUSION: The sCT images generated from MRI data with the Pix2Pix architecture had the lowest image errors and similar dose uncertainties (in term of gamma pass-rate and dose-volume histogram metric differences) than other deep learning methods.
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Aprendizaje Profundo , Próstata , Masculino , Humanos , Tomografía Computarizada por Rayos X/métodos , Imagen por Resonancia Magnética/métodos , Pelvis , Planificación de la Radioterapia Asistida por Computador/métodos , Dosificación RadioterapéuticaRESUMEN
PURPOSE: In radiotherapy, MRI is used for target volume and organs-at-risk delineation for its superior soft-tissue contrast as compared to CT imaging. However, MRI does not provide the electron density of tissue necessary for dose calculation. Several methods of synthetic-CT (sCT) generation from MRI data have been developed for radiotherapy dose calculation. This work reviewed deep learning (DL) sCT generation methods and their associated image and dose evaluation, in the context of MRI-based dose calculation. METHODS: We searched the PubMed and ScienceDirect electronic databases from January 2010 to March 2021. For each paper, several items were screened and compiled in figures and tables. RESULTS: This review included 57 studies. The DL methods were either generator-only based (45% of the reviewed studies), or generative adversarial network (GAN) architecture and its variants (55% of the reviewed studies). The brain and pelvis were the most commonly investigated anatomical localizations (39% and 28% of the reviewed studies, respectively), and more rarely, the head-and-neck (H&N) (15%), abdomen (10%), liver (5%) or breast (3%). All the studies performed an image evaluation of sCTs with a diversity of metrics, with only 36 studies performing dosimetric evaluations of sCT. CONCLUSIONS: The median mean absolute errors were around 76 HU for the brain and H&N sCTs and 40 HU for the pelvis sCTs. For the brain, the mean dose difference between the sCT and the reference CT was <2%. For the H&N and pelvis, the mean dose difference was below 1% in most of the studies. Recent GAN architectures have advantages compared to generator-only, but no superiority was found in term of image or dose sCT uncertainties. Key challenges of DL-based sCT generation methods from MRI in radiotherapy is the management of movement for abdominal and thoracic localizations, the standardization of sCT evaluation, and the investigation of multicenter impacts.
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Aprendizaje Profundo , Imagen por Resonancia Magnética , Estudios Multicéntricos como Asunto , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: The internal target volume (ITV) approach and the mid-ventilation (MidV) concept are the two main respiratory motion-management strategies under free breathing. The purpose of this work was to compare the actual in-treatment target coverage during volumetric modulated arctherapy (VMAT) delivered through both ITV-based and MidV-based planning target volume (PTV) and to provide knowledge in choosing the optimal PTV for stereotactic body radiotherapy (SBRT) for lung lesions. METHODS AND MATERIALS: Thirty-two lung cancer patients treated by a VMAT technique were included in the study. For each fraction, the mean time-weighted position of the target was localized by using a 4-dimensional cone-beam CT (4D-CBCT)-based image guidance procedure. The respiratory-correlated location of the gross tumor volume (GTV) during treatment delivery was determined for each fraction by using in-treatment 4D-CBCT images acquired concurrently with VMAT delivery (4D-CBCTin-treat). The GTV was delineated from each of the ten respiratory phase-sorted 4D-CBCTin-treat datasets for each fraction. We defined target coverage as the average percentage of the GTV included within the PTV during the patient's breathing cycle averaged over the treatment course. Target coverage and PTVs were reported for a MidV-based PTV (PTVMidV) using dose-probabilistic margins and three ITV-based PTVs using isotropic margins of 5 mm (PTVITV + 5mm), 4 mm (PTVITV + 4mm) and 3 mm (PTVITV + 3mm). The in-treatment baseline displacements and target motion amplitudes were reported to evaluate the impact of both parameters on target coverage. RESULTS: Overall, 100 4D-CBCTin-treat images were analyzed. The mean target coverage was 98.6, 99.6, 98.9 and 97.2% for PTVMidV, PTVITV + 5mm, PTVITV + 4mm and PTVITV + 3mm, respectively. All the PTV margins led to a target coverage per treatment higher than 95% in at least 90% of the evaluated cases. Compared to PTVITV + 5mm, PTVMidV, PTVITV + 4mm and PTVITV + 3mm had mean PTV reductions of 16, 19 and 33%, respectively. CONCLUSION: When implementing VMAT with 4D-CBCT-based image guidance, an ITV-based approach with a tighter margin than the commonly used 5 mm margin remains an alternative to the MidV-based approach for reducing healthy tissue exposure in lung SBRT. Compared to PTVMidV, PTVITV + 3mm significantly reduced the PTV while still maintaining an adequate in-treatment target coverage.
Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Tomografía Computarizada Cuatridimensional/métodos , Neoplasias Pulmonares/radioterapia , Radiocirugia/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Humanos , Neoplasias Pulmonares/patologíaRESUMEN
eCHORD is an alternative method for orientation mapping in Scanning Electron Microscopy that involves channeling contrast observed in BSE images. The sample tilt being small (10°), eCHORD could be a promising method for large scale maps as it limits the image deformation sometimes observed with EBSD maps. However, when the magnification is low, the scan deflection of the beam becomes important, which may modify the channeling conditions of analyzed grains, leading to orientation errors. A correction method for the resulting orientations is proposed and a resulting map on a Si single crystal is presented with an experimental misorientation of 0.12° across a field of view of 2.3 × 1.7 mm2.
RESUMEN
Efficient communication between professionals is of upmost importance in improving treatment safety in a radiotherapy department, and is also necessary to enhance the quality of work life. Taking as example the organizations in industry, a self-managed team centred on patients with head and neck cancers treated with radiation has been implemented in 2018 in centre Jean-Bernard (Le Mans, France). After over a year's experience, a real benefice has been found and validates the plan to extend this model to other departments.
Asunto(s)
Comunicación , Neoplasias de Cabeza y Cuello/radioterapia , Departamentos de Hospitales , Relaciones Interprofesionales , Grupo de Atención al Paciente/organización & administración , Oncología por Radiación , Francia , HumanosRESUMEN
PURPOSE: To guide parotid gland (PG) sparing at the dose planning step, a specific model based on overlap between PTV and organ at risk (Moore et al.) was developed and evaluated for VMAT in head-and-neck (H&N) cancer radiotherapy. MATERIALS AND METHODS: One hundred and sixty patients treated for locally advanced H&N cancer were included. A model optimization was first performed (20 patients) before a model evaluation (110 patients). Thirty cases were planned with and without the model to quantify the PG dose sparing. The inter-operator variability was evaluated on one case, planned by 12 operators with and without the model. The endpoints were PG mean dose (Dmean), PTV homogeneity and number of monitor units (MU). RESULTS: The PG Dmean predicted by the model was reached in 89% of cases. Using the model significantly reduced the PG Dmean: -6.1±4.3Gy. Plans with the model showed lower PTV dose homogeneity and more MUs (+10.5% on average). For the inter-operator variability, PG dose volume histograms without the optimized model were significantly different compared to those with the model; the Dmean standard deviation for the ipsilateral PG decreased from 2.2Gy to 1.2Gy. For the contralateral PG, this value decreased from 2.9Gy to 0.8Gy. CONCLUSION: During the H&N inverse planning, the optimized model guides to the lowest PG achievable mean dose, allowing a significant PG mean dose reduction of -6.1Gy. Integrating this method at the treatment-planning step significantly reduced the inter-patient and inter-operator variabilities.
Asunto(s)
Neoplasias de Cabeza y Cuello/radioterapia , Órganos en Riesgo , Glándula Parótida , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada/métodos , Carcinoma de Células Escamosas/radioterapia , Humanos , Glándula Parótida/efectos de la radiación , Planificación de la Radioterapia Asistida por Computador/métodosRESUMEN
Crystalline orientation maps are obtained in a Focused Ion Beam (FIB) microscope using the ion CHanneling ORientation Determination (iCHORD) method, which relies on the channeling phenomenon observed in ion-induced secondary electron images. The current paper focuses on the angular resolution that can be expected from such orientation maps, obtained using a revisited ion channeling model. A specific procedure was developed to evaluate the angular resolution, based on the distribution of orientation errors when evaluating controlled sample disorientation. The main advantage is that no external reference is required. An angular resolution of 1° is obtained on a nickel based sample using standard acquisition conditions. This value fulfills most of the needs in terms of microstructural characterization usually carried out by Electron Back Scattered Diffraction.