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1.
Anticancer Res ; 41(4): 2101-2110, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33813420

RESUMO

BACKGROUND/AIM: To evaluate if topical support therapy during static-intensity modulated radiotherapy (sIMRT) course is able to equal the characteristic minimum risk for radiation proctitis of Image-guided volumetric modulated arc therapy (IG-VMAT) treatment among localized prostate cancer patients. PATIENTS AND METHODS: Rectal toxicity data of the above patients were retrospectively collected throughout three different clinical periods at our Radiotherapy Deparment: from October 2011 to December 2012, prostate cancer patients were treated with sIMRT and in advance supported by means of daily topical corticosteroids; from January 2013 to November 2016, topical corticosteroids were replaced by daily hyaluronic acid enemas; from December 2016 to May 2018 eligible patients were treated with newly introduced IG-VMAT supported by only on-demand topical corticosteroids. RESULTS: Among 359 eligible patients, IG-VMAT was proven generally more effective than sIMRT supported by topical medications in terms of proctitis reduction, although without clinical and practical relevance. CONCLUSION: Topical medications might have a role in radiation proctitis prevention.


Assuntos
Anti-Inflamatórios/administração & dosagem , Proctite/prevenção & controle , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/radioterapia , Radioterapia de Intensidade Modulada , Administração Tópica , Idoso , Idoso de 80 Anos ou mais , Beclometasona/administração & dosagem , Enema/métodos , Humanos , Ácido Hialurônico/administração & dosagem , Itália , Masculino , Pessoa de Meia-Idade , Tratamentos com Preservação do Órgão/métodos , Proctite/etiologia , Neoplasias da Próstata/patologia , Hipofracionamento da Dose de Radiação , Lesões por Radiação/prevenção & controle , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/efeitos adversos , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos
2.
Int. j. med. surg. sci. (Print) ; 8(1): 1-9, mar. 2021. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1151572

RESUMO

El tratamiento con radioterapia, consiste en irradiar de forma homogénea el tumor, evitando irradiar los órganos cercanos. El desarrollo de la tecnología en el campo de la medicina, ha permitido que se cumpla este principio, con buenos resultados de respuesta objetiva, que se traduce en el control de la enfermedad de los pacientes con cáncer. La Tomografía axial computarizada por emisión de positrones (PET-CT) consigue una mayor precisión en el delineado del volumen blanco o tumoral. El propósito de este estudio fue analizar la influencia del uso del PET-CT en el delineado de volúmenes a tratar en la planificación del tratamiento con radiaciones.Se diseñó un estudio piloto con dos pacientes preparados para radioterapia por neoplasias malignas, a los cuáles se les realizó un TAC simple y un PET-CT y observadores independientes realizaron la delimitación del tumor. Se examinó la consistencia entre los observadores y las mediciones en las imágenes.El uso del PET-CT favoreció la delimitación del volumen a irradiar lo que disminuye el riesgo para los órganos vecinos.


The treatment with radiotherapy consists on irradiating in a homogeneous way the tumor, avoiding to irradiate the near organs. The development of the technology in the field of the medicine, it has allowed that this principle is completed, with good results of objective answer what allows the control of the illness of the patients with cancer. The computerized axial tomography by positrons emission (PET-CT) it gets a bigger precision in the one delineated of the white volume or tumoral. The purpose of this study was to analyze the influence of the use of the PET-CT in the one delineated of volumes to try in the planning of the treatment with radiations.A study pilot was designed with two prepared patients for radiotherapy for malignant diseases, to those which they were carried out a simple TAC and a PET-CT and independent observers carried out the delimitation of the tumor. The consistency was examined between the observers and the mensuration in the images.The use of the PET-CT favors the delimitation of the volume to irradiate what diminishes the risk for the neighboring organs.


Assuntos
Humanos , Masculino , Radioterapia/métodos , Radioterapia Guiada por Imagem/métodos , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Radioterapia (Especialidade)/métodos , Neoplasias/radioterapia , Neoplasias/diagnóstico por imagem
3.
Br J Radiol ; 94(1120): 20201014, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33733813

RESUMO

OBJECTIVES: In real-time portal dosimetry, thresholds are set for several measures of difference between predicted and measured images, and signals larger than those thresholds signify an error. The aim of this work is to investigate the use of an additional composite difference metric (CDM) for earlier detection of errors. METHODS: Portal images were predicted for the volumetric modulated arc therapy plans of six prostate patients. Errors in monitor units, aperture opening, aperture position and path length were deliberately introduced into all 180 segments of the treatment plans, and these plans were delivered to a water-equivalent phantom. Four different metrics, consisting of central axis signal, mean image value and two image difference measures, were used to identify errors, and a CDM was added, consisting of a weighted power sum of the individual metrics. To optimise the weights of the CDM and to evaluate the resulting timeliness of error detection, a leave-pair-out strategy was used. For each combination of four patients, the weights of the CDM were determined by an exhaustive search, and the result was evaluated on the remaining two patients. RESULTS: The median segment index at which the errors were identified was 87 (range 40-130) when using all of the individual metrics separately. Using a CDM as well as multiple separate metrics reduced this to 73 (35-95). The median weighting factors of the four metrics constituting the composite were (0.15, 0.10, 0.15, 0.00). Due to selection of suitable threshold levels, there was only one false positive result in the six patients. CONCLUSION: This study shows that, in conjunction with appropriate error thresholds, use of a CDM is able to identify increased image differences around 20% earlier than the separate measures. ADVANCES IN KNOWLEDGE: This study shows the value of combining difference metrics to allow earlier detection of errors during real-time portal dosimetry for volumetric modulated arc therapy treatment.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/métodos , Humanos , Masculino , Imagens de Fantasmas , Próstata/diagnóstico por imagem , Radiometria , Dosagem Radioterapêutica , Estudos Retrospectivos
4.
Anticancer Res ; 41(3): 1587-1592, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33788753

RESUMO

BACKGROUND/AIM: Modern intensity-modulated radiotherapy (IMRT) is frequently applied to treat patients with nasal cavity and paranasal sinus (NC/PNS) malignancies. PATIENTS AND METHODS: One hundred and four patients who underwent radiotherapy (RT) between 1994 and 2020 were recognized. This analysis compared conventional-radiotherapy (CRT) and image-guided IMRT outcomes for NC/PNS malignancies. RESULTS: The median follow-up was 69 months. Eighty-eight patients (85%) were managed with image-guided IMRT. The median initial radiation dose was 65 Gy, with 68 Gy applied for patients treated with primary RT versus 63 Gy applied for adjuvant therapy (p=0.1). The 5-year locoregional control (LRC) was 85%. The locoregional recurrence rate was 18% following IMRT versus 31% in the 2D/3D-conventional RT group (p=0.09). Moreover, IMRT was associated with a lower inner-ear toxicity rate (8% vs. 20%, respectively; p=0.045). CONCLUSION: IMRT appears to be linked with higher LRC and lower inner-ear acute toxicities compared to conventional RT.


Assuntos
Cavidade Nasal , Neoplasias Nasais/radioterapia , Neoplasias dos Seios Paranasais/radioterapia , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/epidemiologia , Dosagem Radioterapêutica , Radioterapia Guiada por Imagem/efeitos adversos , Radioterapia de Intensidade Modulada/efeitos adversos
5.
Cancer Radiother ; 25(2): 119-125, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33676829

RESUMO

PURPOSE: To evaluate the safety and efficacy of Cyberknife® (CK) for the treatment of primary or recurring thymic tumours. MATERIALS AND METHODS: We retrospectively reviewed 12 patients (16 tumour lesions) with primary or recurring thymic tumours who were treated with CK between March 2008 and October 2017. Their data was stored in prospectively collected database. Kaplan-Meier method was used to calculate survival curves. RESULTS: Five patients (41.7%), who had inoperable disease or refused surgery, were treated with CK initially, and 7 patients (58.3%) were treated with CK when they had recurrence diseases. The disease sites treated with CK were primary tumour site (5), regional lymph nodes (4), tumour bed (3), chest wall (2), pleura (1), and bone (1). The median target volume was 43.8 cm3 (range, 13.1-302.5cm3) for the 16 tumour lesions. The median follow-up time was 69.3 months (range, 9.7-124.8 months). The median survival time was 48.2 months, and the 5-year and 10-year OS rates were 68.2% and 45.5%, respectively. A high response rate for the tumour lesions irradiated with CK was obtained. Only one patient (8%) experienced in-field recurrence, and the 5-year local recurrence free survival was 90.9%. A case indicated that CK may induce the abscopal effect, which provides the potential to combine CK and immunotherapy. No severe radiation related toxicities were observed, and no treatment related death occurred. CONCLUSION: CK treatment resulted in good outcomes, particularly local control, with minimal side effects, in highly selected patients with primary and recurring thymic tumours. More studies with larger sample are needed.


Assuntos
Recidiva Local de Neoplasia/radioterapia , Radiocirurgia/métodos , Radioterapia Guiada por Imagem/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Timoma/radioterapia , Neoplasias do Timo/radioterapia , Adulto , Idoso , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/secundário , Irradiação Linfática , Masculino , Neoplasias do Mediastino/radioterapia , Neoplasias do Mediastino/secundário , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Radiocirurgia/efeitos adversos , Radioterapia Guiada por Imagem/efeitos adversos , Estudos Retrospectivos , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Segurança , Taxa de Sobrevida , Timoma/mortalidade , Timoma/patologia , Timoma/secundário , Neoplasias do Timo/mortalidade , Neoplasias do Timo/patologia , Fatores de Tempo
6.
Cancer Radiother ; 25(2): 135-140, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33422419

RESUMO

PURPOSE: To investigate the Gross Tumor Volumes (GTV) and its dosimetric impact of magnetic resonance imaging (MRI) assisted contouring for non-spinal metastasis treated with stereotactic ablative body radiotherapy (SABR). MATERIAL AND METHODS: Five observer contours on CT (GTVCT) and CT+MR (GTVCT+MR) were evaluated against expert team contours (GTVEC) for 14 selected cases. Dice Similarity Index (DSC) and Geographical Miss Index (GMI) quantify observer variation. We also analyze the maximum dose (Dmax) and dose received by 0.35cc (D0.35cc) of the spinal cord (SC) for GTVCT and GTVCT+MR, where optimization parameters and priorities were unchanged. Percent rank function is also evaluated for SC doses. RESULTS: The mean DSC and GMI scores for the CT-only dataset are 0.6974 and 0.2851 and for CT+MR dataset is 0.7764 and 0.1907 respectively. Statistically, significant results were found for mean GTV volumes between GTVEC versus GTVCT and GTVCT versus GTVCT+MR (P<0.001). Dosimetric analysis of Dmax and D0.35cc exceeded 84.2% and 88.5% of times its respective threshold doses for CT-only dataset, whereas for the CT+MR dataset, it exceeded only by 18% and 15.7% times. 'Percent rank' function analysis for SC doses also indicates the same. CONCLUSION: This study supports MRI fusion for GTV and OAR delineation for non-spinal metastasis. Our study showed that the dosimetric analysis is vital for observer variation studies and the addition of the MR data set is significant to improve the confidence of Stereotactic treatments.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/radioterapia , Imagem por Ressonância Magnética/métodos , Órgãos em Risco/diagnóstico por imagem , Radiocirurgia/métodos , Carga Tumoral , Algoritmos , Neoplasias Ósseas/patologia , Conjuntos de Dados como Assunto , Fracionamento da Dose de Radiação , Feminino , Humanos , Masculino , Variações Dependentes do Observador , Radioterapia Guiada por Imagem/métodos , Estudos Retrospectivos , Coluna Vertebral , Tomografia Computadorizada por Raios X/métodos
7.
Br J Radiol ; 94(1119): 20200239, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33353402

RESUMO

OBJECTIVE: This study aimed to assess the dosimetric effect of intestinal gas of stereotactic magnetic resonance (MR)-guided adaptive radiation therapy (SMART) on target and critical organs for pancreatic cancer without online electron density correction (EDC). METHODS: Thirty pancreatic cancer patients who underwent online SMART were selected for this study. The treatment time of each stage and the total treatment time were recorded and analyzed. The concerned dose-volume parameters of target and organs-at-risk (OAR) were compared with and without an intestinal gas EDC using the Wilcoxon-signed rank test. Analysis items with p value < 0.05 were considered statistically significant. The relationships between dosimetric differences and intestinal gas volume variations were investigated using the Spearman test. RESULTS: The average treatment time was 82 min, and the average EDC time was 8 min, which accounted for 10% of the overall treatment time. There were no significant differences in CTV (GTV), PTV, bowel, stomach, duodenum, and skin (p > 0.05) with respect to dose volume parameters. For the Dmax of gastrointestinal organs (p = 0.03), the mean dose of the liver (p = 0.002) and kidneys (p = 0.03 and p = 0.04 for the left and right kidneys, respectively), there may be a risk of slight overestimation compared with EDC, and for the Dmax of the spinal cord (p = 0.02), there may be a risk of slight underestimation compared with EDC. A weak correlation for D95 in the PTV and D0.5 cc in the duodenum was observed. CONCLUSION: For patients with similar inter-fractional intestinal gas distribution, EDC had little dosimetric effects on the D0.5 cc of all GI organs and dose volume parameters of target in most plans. ADVANCES IN KNOWLEDGE: By omitting the EDC of intestinal gas, the online SMART treatment time can be shortened.


Assuntos
Imagem por Ressonância Magnética Intervencionista/métodos , Órgãos em Risco/efeitos da radiação , Neoplasias Pancreáticas/radioterapia , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Elétrons , Feminino , Humanos , Intestinos/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica
9.
Technol Cancer Res Treat ; 19: 1533033820974021, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33327884

RESUMO

PURPOSE: With the widespread prevalence of Corona Virus Disease 2019 (COVID-19), cancer patients are suggested to wear a surgical mask during radiation treatment. In this study, cone beam CT (CBCT) was used to investigate the effect of surgical mask on setup errors in head and neck radiotherapy. METHODS: A total of 91 patients with head and neck tumors were selected. CBCT was performed to localize target volume after patient set up. The images obtained by CBCT before treatment were automatically registered with CT images and manually fine-tuned. The setup errors of patients in 6 directions of Vrt, Lng, Lat, Pitch, Roll and Rotation were recorded. The patients were divided into groups according to whether they wore the surgical mask, the type of immobilization mask used and the location of the isocenter. The setup errors of patients were calculated. A t-test was performed to detect whether it was statistically significant. RESULTS: In the 4 groups, the standard deviation in the directions of Lng and Pitch of the with surgical mask group were all higher than that in the without surgical mask group. In the head-neck-shoulder mask group, the mean in the Lng direction of the with surgical mask group was larger than that of the without surgical mask group. In the lateral isocenter group, the mean in the Lng and Pitch directions of the with surgical mask group were larger than that of the without surgical mask group. The t-test results showed that there was significant difference in the setup error between the 2 groups (p = 0.043 and p = 0.013, respectively) only in the Lng and Pitch directions of the head-neck-shoulder mask group. In addition, the setup error of 6 patients with immobilization open masks exhibited no distinguished difference from that of the patients with regular immobilization masks. CONCLUSION: In the head and neck radiotherapy patients, the setup error was affected by wearing surgical mask. It is recommended that the immobilization open mask should be used when the patient cannot finish the whole treatment with a surgical mask.


Assuntos
/prevenção & controle , Neoplasias de Cabeça e Pescoço/radioterapia , Máscaras , Erros de Configuração em Radioterapia/estatística & dados numéricos , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Tomografia Computadorizada de Feixe Cônico/métodos , Feminino , Neoplasias de Cabeça e Pescoço/epidemiologia , Humanos , Imobilização/instrumentação , Imobilização/métodos , Imobilização/estatística & dados numéricos , Masculino , Máscaras/efeitos adversos , Máscaras/estatística & dados numéricos , Pessoa de Meia-Idade , Pandemias , Radioterapia (Especialidade)/métodos , Radioterapia (Especialidade)/normas , Planejamento da Radioterapia Assistida por Computador/efeitos adversos , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/estatística & dados numéricos , Radioterapia Guiada por Imagem/efeitos adversos , Radioterapia Guiada por Imagem/métodos , Radioterapia Guiada por Imagem/estatística & dados numéricos , Radioterapia de Intensidade Modulada/métodos , Ombro , Adulto Jovem
10.
Anticancer Res ; 40(11): 6499-6503, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33109589

RESUMO

BACKGROUND/AIM: Late toxicity and long-term outcomes of a phase I-II trial on patients with prostate cancer treated with an integrated boost to the dominant intraprostatic lesion (DIL) are reported. PATIENTS AND METHODS: Patients were treated using intensity-modulated radiotherapy, with a simultaneous integrated boost to the DIL, defined on staging magnetic resonance imaging, delivering 72 Gy in 1.8 Gy/fraction to prostate/seminal vesicles and 80 Gy in 2 Gy/fraction to the DIL. The primary endpoint was acute toxicity and secondary endpoints were late toxicity and biochemical disease-free survival. RESULTS: Forty-four patients were enrolled. The median follow-up was 120 (range=25-150) months. Five-year rates of grade 3 late gastrointestinal and genitourinary toxicity were 2.3% and 4.5%, respectively; only one grade 4 late genitourinary toxicity was recorded. Five-year biochemical relapse-free and overall survival rates were 95.3% and 95.5%, respectively. CONCLUSION: The treatment was well tolerated and achieved excellent results in terms of outcome in patients with low-intermediate Gleason's score and low risk of nodal metastasis.


Assuntos
Próstata/efeitos da radiação , Neoplasias da Próstata/radioterapia , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Próstata/diagnóstico por imagem , Próstata/patologia , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Radioterapia de Intensidade Modulada/efeitos adversos
11.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 39(5): 327-336, sept.-oct. 2020. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-198297

RESUMO

La detección de nódulos pulmonares se ha incrementado en las últimas décadas debido a la introducción de los programas de cribado del cáncer de pulmón y al aumento de las exploraciones rutinarias de tomografía computarizada en los pacientes con neoplasias. La biopsia percutánea de estos nódulos no siempre permite caracterizarlos, por lo que en ocasiones es necesaria la biopsia quirúrgica, que a menudo requiere de localización prequirúrgica. La resección radioguiada de lesiones ocultas (ROLL) descrita para las lesiones mamarias se aplicó por primera vez en la resección de nódulos pulmonares en el año 2000, siendo en la actualidad una alternativa a otras técnicas de localización prequirúrgica como la resección guiada por arpón. La técnica aporta elevada tasa de detección con mínima morbimortalidad, potenciando el trabajo multidisciplinar entre los especialistas en Medicina Nuclear y los especialistas de radiodiagnóstico y cirugía torácica. En este trabajo, se describen las diferentes técnicas de localización prequirúrgica disponibles, los procesos metodológicos de la técnica ROLL y los resultados acumulados en 20 años de experiencia


The detection of pulmonary nodules has increased in recent decades due to the introduction of lung cancer screening programs and the massively use of routine chest computed tomography in patients with malignant neoplasms. Percutaneous biopsy of these nodules does not always characterize them, so sometimes a surgical biopsy is necessary, which often requires a presurgical localization. The radioguided occult lesion localization (ROLL) described for breast lesions was first applied in the resection of pulmonary nodules in 2000, becoming an alternative to other presurgical localization techniques such as hook-wire. The technique provides high detection rate with minimal morbidity, enhancing multidisciplinary work with specialists in Radiology and Chest Surgery. The present paper describes the different pre-surgical localization techniques currently available, the methodological procedure of the ROLL technique and the collected results in 20 years of experience


Assuntos
Humanos , Nódulos Pulmonares Múltiplos/diagnóstico por imagem , Radiocirurgia/métodos , Nódulo Pulmonar Solitário/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Nódulos Pulmonares Múltiplos/cirurgia , Radioterapia Guiada por Imagem/métodos , Nódulo Pulmonar Solitário/cirurgia , Neoplasias Primárias Desconhecidas/diagnóstico por imagem , Neoplasias Pulmonares/cirurgia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos
12.
Br J Radiol ; 93(1114): 20200028, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783629

RESUMO

OBJECTIVE: To determine the toxicity reduction required to justify the added costs of MRI-guided radiotherapy (MR-IGRT) over CT-based image guided radiotherapy (CT-IGRT) for the treatment of localized prostate cancer. METHODS: The costs of delivering prostate cancer radiotherapy with MR-IGRT and CT-IGRT in conventional 39 fractions and stereotactic body radiotherapy (SBRT) 5 fractions schedules were determined using literature values and cost accounting from two institutions. Gastrointestinal and genitourinary toxicity rates associated with CT-IGRT were summarized from 20 studies. Toxicity-related costs and utilities were obtained from literature values and cost databases. Markov modeling was used to determine the savings per patient for every 1% relative reduction in acute and chronic toxicities by MR-IGRT over 15 years. The costs and quality adjusted life years (QALYs) saved with toxicity reduction were juxtaposed with the cost increase of MR-IGRT to determine toxicity reduction thresholds for cost-effectiveness. One way sensitivity analyses were performed. Standard $100,000 and $50,000 per QALY ratios were used. RESULTS: The added cost of MR-IGRT was $1,459 per course of SBRT and $10,129 per course of conventionally fractionated radiotherapy. Relative toxicity reductions of 7 and 14% are required for SBRT to be cost-effective using $100,000 and $50,000 per QALY, respectively. Conventional radiotherapy requires relative toxicity reductions of 50 and 94% to be cost-effective. CONCLUSION: From a healthcare perspective, MR-IGRT can reasonably be expected to be cost-effective. Hypofractionated schedules, such a five fraction SBRT, are most likely to be cost-effective as they require only slight reductions in toxicity (7-14%). ADVANCES IN KNOWLEDGE: This is the first detailed economic assessment of MR-IGRT, and it suggests that MR-IGRT can be cost-effective for prostate cancer treatment through toxicity reduction alone.


Assuntos
Imagem por Ressonância Magnética Intervencionista/economia , Neoplasias da Próstata/radioterapia , Radiografia Intervencionista/economia , Radioterapia Guiada por Imagem/métodos , Tomografia Computadorizada por Raios X/economia , Adulto , Idoso , Análise Custo-Benefício , Humanos , Masculino , Cadeias de Markov , Pessoa de Meia-Idade , Anos de Vida Ajustados por Qualidade de Vida , Planejamento da Radioterapia Assistida por Computador
13.
Br J Radiol ; 93(1115): 20200412, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32822249

RESUMO

OBJECTIVE: To evaluate the performance of low dose cone beam CT (CBCT) acquisition protocols for image-guided radiotherapy of prostate cancer. METHODS: CBCT images of patients undergoing prostate cancer radiotherapy were acquired with the settings currently used in our department and two low dose settings at 50% and 63% lower exposure. Four experienced radiation oncologists and two radiation therapy technologists graded the images on five image quality characteristics. The scores were analysed through Visual Grading Regression, using the acquisition settings and the patient size as covariates. RESULTS: The low dose acquisition settings have no impact on the image quality for patients with body profile length at hip level below 100 cm. CONCLUSIONS: A reduction of about 60% of the dose is feasible for patients with size below 100 cm. The visibility of low contrast features can be compromised if using the low dose acquisition settings for patients with hip size above 100 cm. ADVANCES IN KNOWLEDGE: Low dose CBCT acquisition protocols for the pelvis, based on subjective evaluation of patient images.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Aceleradores de Partículas , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/métodos , Estudos de Viabilidade , Humanos , Masculino , Pelve/diagnóstico por imagem , Doses de Radiação , Radioterapia Guiada por Imagem/instrumentação , Radioterapia de Intensidade Modulada/instrumentação , Análise de Regressão
14.
Cancer Radiother ; 24(6-7): 635-644, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32859466

RESUMO

Adaptive radiotherapy (ART) corresponds to various replanning strategies aiming to correct for anatomical variations occurring during the course of radiotherapy. The goal of the article was to report the rational, feasibility and benefit of using PET and/or MRI to guide this ART strategy in various tumor localizations. The anatomical modifications defined by scanner taking into account tumour mobility and volume variation are not always sufficient to optimise treatment. The contribution of functional imaging by PET or the precision of soft tissue by MRI makes it possible to consider optimized ART. Today, the most important data for both PET and MRI are for lung, head and neck, cervical and prostate cancers. PET and MRI guided ART appears feasible and safe, however in a very limited clinical experience. Phase I/II studies should be therefore performed, before proposing cost-effectiveness comparisons in randomized trials and before using the approach in routine practice.


Assuntos
Imagem por Ressonância Magnética , Neoplasias/radioterapia , Tomografia por Emissão de Pósitrons , Radioterapia Guiada por Imagem/métodos , Estudos de Viabilidade , Feminino , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Neoplasias Pulmonares/radioterapia , Masculino , Neoplasias da Próstata/radioterapia , Neoplasias do Colo do Útero/radioterapia
15.
Br J Radiol ; 93(1112): 20200169, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32543946

RESUMO

OBJECTIVES: The aim of this study was to assess the consistency of therapy radiographers performing image registration using cone beam computed tomography (CBCT)-CT, magnetic resonance (MR)-CT, and MR-MR image guidance for cervix cancer radiotherapy and to assess that MR-based image guidance is not inferior to CBCT standard practice. METHODS: 10 patients receiving cervix radiation therapy underwent daily CBCT guidance and magnetic resonance (MR) imaging weekly during treatment. Offline registration of each MR image, and corresponding CBCT, to planning CT was performed by five radiographers. MR images were also registered to the earliest MR interobserver variation was assessed using modified Bland-Altman analysis with clinically acceptable 95% limits of agreement (LoA) defined as ±5.0 mm. RESULTS: 30 CBCT-CT, 30 MR-CT and 20 MR-MR registrations were performed by each observer. Registration variations between CBCT-CT and MR-CT were minor and both strategies resulted in 95% LoA over the clinical threshold in the anteroposterior direction (CBCT-CT ±5.8 mm, MR-CT ±5.4 mm). MR-MR registrations achieved a significantly improved 95% LoA in the anteroposterior direction (±4.3 mm). All strategies demonstrated similar results in lateral and longitudinal directions. CONCLUSION: The magnitude of interobserver variations between CBCT-CT and MR-CT were similar, confirming that MR-CT radiotherapy workflows are comparable to CBCT-CT image-guided radiotherapy. Our results suggest MR-MR radiotherapy workflows may be a superior registration strategy. ADVANCES IN KNOWLEDGE: This is the first publication quantifying interobserver registration of multimodality image registration strategies for cervix radical radiotherapy patients.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Imagem por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Variações Dependentes do Observador , Radioterapia Guiada por Imagem/métodos , Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Colo do Útero/diagnóstico por imagem , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/diagnóstico por imagem
16.
Cancer Radiother ; 24(5): 411-417, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32517893

RESUMO

Improved computer resources in radiation oncology department have greatly facilitated the integration of multimodal imaging into the workflow of radiation therapy. Nowadays, physicians have highly informative imaging modalities of the anatomical region to be treated. These images contribute to the targeting accuracy with the current treatment device, impacting both segmentation or patient's positioning. Additionally, in a constant effort to deliver personalized care, many teams seek to confirm the benefits of adaptive radiotherapy. The published works highlight the importance of registration algorithms, particularly those of elastic or deformable registration necessary to take into account the anatomical evolutions of the patients during the course of their therapy. These algorithms, often considered as "black boxes", tend to be better controlled and understood by physicists and physicians thanks to the generalization of evaluation and validation methods. Given the still significant development of medical imaging techniques, it is foreseeable that multimodal registration needs require more efficient algorithms well integrated within the flow of data.


Assuntos
Algoritmos , Imagem Multimodal/métodos , Posicionamento do Paciente/métodos , Radioterapia Guiada por Imagem/métodos , Fracionamento da Dose de Radiação , Feminino , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Imagem por Ressonância Magnética , Imagem Multimodal/normas , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/radioterapia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Controle de Qualidade , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Radioterapia Guiada por Imagem/normas , Tomografia Computadorizada por Raios X , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/radioterapia
17.
Phys Med Biol ; 65(18): 185001, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32485687

RESUMO

Positron emission tomography (PET) has been used for in vivo treatment verification, mainly for range verification, in proton therapy. Evaluating the direct dose from PET measurements remains challenging; however, it is highly desirable from a clinical perspective. In this study, a method for estimating the dose distribution from the positron emitter distributions was developed using the maximum likelihood expectation maximization algorithm. The 1D spatial relationship between positron emitter distributions and a dose distribution in an inhomogeneous target was inputted into the system matrix based on a filter framework. In contrast, spatial resolution of the PET system and total variation regularization (as prior knowledge for dose distribution) were considered in the 3D image-space. The dose estimation was demonstrated using Monte Carlo simulated PET activity distributions with substantial noise in a head and neck phantom. This mimicked the single field irradiation of the spread-out Bragg peak beams at clinical dose levels. Besides the simple implementation of the algorithm, this strategy achieved a high-speed calculation (30 s for a 3D dose estimation) and accurate dose and range estimations (less than 10% and 2 mm errors at 1-σ values, respectively). The proposed method could be key for using PET for in vivo dose monitoring.


Assuntos
Algoritmos , Tomografia por Emissão de Pósitrons , Terapia com Prótons/métodos , Doses de Radiação , Radioterapia Guiada por Imagem/métodos , Humanos , Funções Verossimilhança , Método de Monte Carlo , Imagens de Fantasmas , Dosagem Radioterapêutica
18.
J Cancer Res Ther ; 16(2): 372-378, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32474526

RESUMO

Aims: The aim was to evaluate the feasibility and clinical value of computed tomography (CT)-guided125 I brachytherapy for pain palliation in patients with retroperitoneal lymph node metastases. Materials and Methods: A total of 23 patients with retroperitoneal lymph node metastases and those who had moderate-to-severe pain from January 2014 to December 2018 were enrolled in the study. The primary tumors included pancreatic (n = 12), gastric (n = 4), hepatocellular (n = 4), colorectal (n = 2), and esophageal carcinomas (n= 1). Patients were treated with CT-guided percutaneous125 I brachytherapy during the study. The Brief Pain Inventory-Short Form was used to record and compare pain intensity and interference by pain. Treatment-related complications were also evaluated according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Criteria. Statistical analysis was performed using SPSS software version 22.0. Results: The primary success rate of125 I seed implantation was 95.7% (22 of the 23 patients). As pain evolved, the patients achieved obvious pain palliation ratings for "worst pain" and "average pain" at 72 h and 4 weeks after brachytherapy, respectively, whereas "pain right now" at 12 weeks was significantly relieved after brachytherapy. No serious complications developed during the perioperative period. Conclusions: In the treatment of intractable carcinomatous pain in patients with retroperitoneal lymph node metastases, CT-guided125 I brachytherapy is a feasible and effective modality for pain palliation.


Assuntos
Braquiterapia/métodos , Radioisótopos do Iodo/uso terapêutico , Linfonodos/patologia , Neoplasias/radioterapia , Manejo da Dor/métodos , Radioterapia Guiada por Imagem/métodos , Neoplasias Retroperitoneais/radioterapia , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias/patologia , Neoplasias Retroperitoneais/secundário , Estudos Retrospectivos , Resultado do Tratamento
19.
Indian J Cancer ; 57(2): 182-186, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32445322

RESUMO

Introduction: Pelvic radiotherapy is generally performed with the use of an immobilization and positioning device. Aim and objective: The objective of the study was to ascertain and compare setup errors between the two positioning devices. Materials and methods: A total of 35 patients of stage II and III cervical cancers were enrolled in the study and divided into two groups, one using knee wedge and the other using thermoplastic pelvic mask as an immobilization device. Radiation was planned by four field box conformal technique. The random and systematic setup errors were then calculated for each patient in both the groups in the mediolateral (ML), superoinferior (SI), and anteroposterior (AP) directions. Results: The translational mean setup variation in the lateral, longitudinal, and vertical direction is 0.17 ± 0.24, -0.12 ± 0.48, and -0.18 ± 0.27 cm for thermoplastic pelvic mask and -0.03 ± 0.26, -0.04 ± 0.48, and -0.09 ± 0.37 cm for knee wedge, respectively. The systematic setup error and random errors were 0.24, 0.48, 0.27 cm and 0.31, 0.60, and 0.40 cm for thermoplastic mask and 0.26, 0.48, and 0.37 cm and 0.38, 0.37, and 0.45 cm for knee wedge in ML, SI, and AP axis, respectively. The one way analysis of variance test was applied to compare the setup errors in between the three axes for both the immobilization devices. To compare the positioning accuracy of thermoplastic mask and knee wedge, Student's t-test was applied. Both the tests were found to be insignificant (P value > 0.05). Conclusion: Thermoplastic mask and knee wedge are equally effective as immobilization devices for treating cervical cancers with conformal techniques.


Assuntos
Imobilização/instrumentação , Radioterapia Guiada por Imagem/métodos , Neoplasias do Colo do Útero/radioterapia , Tomografia Computadorizada de Feixe Cônico/instrumentação , Tomografia Computadorizada de Feixe Cônico/métodos , Feminino , Humanos , Imobilização/métodos , Joelho , Máscaras , Posicionamento do Paciente , Pelve/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/instrumentação
20.
Cancer Radiother ; 24(4): 345-353, 2020 Jul.
Artigo em Francês | MEDLINE | ID: mdl-32360094

RESUMO

Preoperative radiotherapy boosted by chemotherapy is a recommended treatment in locally advanced rectal cancers. This treatment is delivered by three dimensional conformal irradiation, which is usually well tolerated but can induce potential toxicity such as rectitis, cystitis and hematologic adverse effects. Intensity-modulated radiotherapy, widely available nowadays, allows optimization of volume covering and sparing of organs at risk such as bladder and bone marrow. This review presents relevant clinical situations and requirements for a beneficial and safe preoperative irradiation of rectal cancers by intensity-modulated technique. This technique is compared to three-dimensional conformal radiotherapy.


Assuntos
Quimiorradioterapia/métodos , Radioterapia de Intensidade Modulada/métodos , Neoplasias Retais/terapia , Humanos , Órgãos em Risco/efeitos da radiação , Cuidados Pré-Operatórios/métodos , Lesões por Radiação/prevenção & controle , Radioterapia Conformacional/efeitos adversos , Radioterapia Guiada por Imagem/métodos , Neoplasias Retais/cirurgia
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