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1.
Int. j. morphol ; 38(2): 252-258, abr. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1056431

RESUMO

The aim of this study was to evaluate the effects of mandibular advancement appliance and low level laser therapy (LLLT) with different doses on cellular hypertrophic changes in the mandibular condyle of rats. Forty-eight 8-week-old male Wistar albino rats weighing between 260 and 280 g were randomly divided into four experimental and control groups. Group I was the control group; group II was the mandibular advancement appliance group; group III was the 8 J/cm2 (0.25 W, 20 s) laser irradiation with mandibular advancement appliance group; and group IV was the 10 J/cm2 (0.25 W, 25 s) laser irradiation with mandibular advancement appliance group. Mandibular condyle cartilage and subchondral bone changes with different LLLT dose and mandibular advancement appliance were evaluated by histomorphometrical analysis. Subchondral bone fraction results showed that there were no significant differences between groups (p<0.05). The statistically significant differences found between control group and experimental groups in anterior and posterior cartilage layers thickness (p<0.05) and (p<0.01). Posterior and anterior condylar cartilage layers of rats react differentially to LLLT and mandibular advancement application. Maximum changes in condylar cartilage layers were found in 8 J/cm2 laser irradiation with mandibular appliance group.


El objetivo de este estudio fue evaluar los efectos del aparato de avance mandibular y la terapia con láser de bajo nivel (TLBN) con diferentes dosis sobre los cambios hipertróficos celulares, en el cóndilo mandibular de ratas. Cuarenta y ocho ratas albinas macho Wistar de 8 semanas de edad con un peso de 260 y 280 g se dividieron aleatoriamente en cuatro grupos experimentales y control. El grupo I control; grupo II, dispositivos de avance mandibular; grupo III de irradiación con láser de 8 J / cm2 (0.25 W, 20 s) con el grupo dispositivos de avance mandibular; y grupo IV con irradiación láser de 10 J / cm2 (0,25 W, 25 s) con el grupo de dispositivos de avance mandibular. El cartílago del cóndilo mandibular y los cambios en el hueso subcondral con diferentes dosis de TLBN y dispositivo de avance mandibular, se evaluaron mediante análisis histomorfométrico. Los resultados de la fracción ósea subcondral indicaron que no hubo diferencias significativas entre los grupos (p <0,05). Las diferencias estadísticamente significativas encontradas entre el grupo control y los grupos experimentales, en el grosor del cartílago anterior y posterior (p<0,05) y (p<0,01). Las capas de cartílago condilar posterior y anterior de las ratas reaccionan de manera diferencial a la aplicación de TLBN y avance mandibular. Se encontraron cambios significativos en las capas de cartílago condilar con irradiación láser de 8 J /cm2 con el grupo de dispositivos mandibulares.


Assuntos
Animais , Masculino , Ratos , Osso e Ossos/efeitos da radiação , Cartilagem Articular/efeitos da radiação , Avanço Mandibular/métodos , Terapia com Luz de Baixa Intensidade/métodos , Osso e Ossos/cirurgia , Cartilagem Articular/cirurgia , Ratos Wistar
2.
DNA Cell Biol ; 39(5): 790-800, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32176536

RESUMO

Interleukin-1 beta (IL1B) is a key inducer of inflammation and an important factor in the regulation of hematopoietic stem cells and mesenchymal stromal progenitors. Irradiation of mice with ionizing radiation has been shown to induce a lasting increase in IL1B concentration in peripheral blood. One of the possible mechanisms may be demethylation of CpG cytosines in the Il1b promoter, which has not been characterized in detail for the mouse. In this study, the methylation level of CpGs located in a region between -3562 and -208 bp upstream of the start of transcription is studied in muscles, bones, liver, thymus, spleen, bone marrow, lymph nodes, lungs, and brain. The methylation level is compared to Il1b expression. Tissue-specific features of CpG methylation are established. It is demonstrated that the region between -2420 and -2406 bp is likely a part of the mouse Il1b promoter/enhancer and may determine the base level of Il1b expression in various tissues. Irradiation at a dose of 6 Gy does not change the methylation profile of most studied CpGs, and therefore, the cause of the stably increased IL1B level after irradiation is unlikely to be a change in the methylation of the studied CpGs in investigated tissues.


Assuntos
Raios gama , Interleucina-1beta/genética , Regiões Promotoras Genéticas/genética , Animais , Osso e Ossos/metabolismo , Osso e Ossos/efeitos da radiação , Ilhas de CpG/genética , Metilação de DNA/efeitos da radiação , Feminino , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Camundongos , Regiões Promotoras Genéticas/efeitos da radiação , Fatores de Transcrição/metabolismo
3.
Br J Radiol ; 93(1107): 20190919, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32003576

RESUMO

OBJECTIVE: Monte Carlo (MC) simulations substantially improve the accuracy of predicted doses. This study aims to determine and quantify the uncertainties of setting up such a MC system. METHODS: Doses simulated with two Geant4-based MC calculation codes, but independently tuned to the same beam data, have been compared. Different methods of MC modelling of a pre-absorber have been employed, either modifying the beam source parameters (descriptive) or adding the pre-absorber as a physical component (physical). RESULTS: After the independent beam modelling of both systems in water (resulting in excellent range agreement) range differences of up to 3.6/4.8 mm (1.5% of total range) in bone/brain-like tissues were found, which resulted from the use of different mean water ionisation potentials during the energy tuning process. When repeating using a common definition of water, ranges in bone/brain agreed within 0.1 mm and gamma-analysis (global 1%,1mm) showed excellent agreement (>93%) for all patient fields. However, due to a lack of modelling of proton fluence loss in the descriptive pre-absorber, differences of 7% in absolute dose between the pre-absorber definitions were found. CONCLUSION: This study quantifies the influence of using different water ionisation potentials during the MC beam modelling process. Furthermore, when using a descriptive pre-absorber model, additional Faraday cup or ionisation chamber measurements with pre-absorber are necessary. ADVANCES IN KNOWLEDGE: This is the first study quantifying the uncertainties caused by the MC beam modelling process for proton pencil beam scanning, and a more detailed beam modelling process for MC simulations is proposed to minimise the influence of critical parameters.


Assuntos
Método de Monte Carlo , Terapia com Prótons/métodos , Incerteza , Absorção de Radiação , Ar , Osso e Ossos/efeitos da radiação , Encéfalo/efeitos da radiação , Humanos , Hipofracionamento da Dose de Radiação , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Água
4.
Appl Radiat Isot ; 154: 108899, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31577979

RESUMO

The present work explores the luminescence behavior of animal bones and more specifically, chicken bones, using OSL in order to investigate whether they can be used for the dose assessment in the case of an accident or as dosimeters at the post-sterilization dosimetry of foods. Results indicate that the OSL sensitivity is rather low and the lower detection limit is ~18 Gy eliminating the possibility of using bones as emergency dosimeter. However, the OSL dose response is linear for doses up to ~1.0 kGy, while response over the entire dose range, up to several kGy, can be fitted with an exponential saturation curve. When bones are kept in dark, half of the initial OSL signal is lost seven days after irradiation, with no further loss for longer time periods up to two months post-irradiation. Since bones are heat-sensitive and exhibit sensitization, a dose recovery test was also conducted using the SARHS protocol in order to investigate if the protocol is capable of calculating the sterilization/accidental dose of irradiated chicken/poultry. The "unknown" doses were successfully recovered even when fading was considered. Considering the fact that bones are not directly exposed to light (protected by the skin and the flesh) or to high temperatures, it seems that they could be used at retrospective dosimetry and the identification of irradiated food products containing bone (food post-sterilization dosimetry).


Assuntos
Osso e Ossos/efeitos da radiação , Irradiação de Alimentos/métodos , Dosimetria por Luminescência Estimulada Opticamente/métodos , Animais , Osso e Ossos/química , Galinhas , Humanos , Técnicas In Vitro , Limite de Detecção , Doses de Radiação , Liberação Nociva de Radioativos , Estudos Retrospectivos
5.
Int J Mol Med ; 44(6): 2265-2275, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31638191

RESUMO

Radiotherapy, one of the clinical treatments of cancer, is accompanied by a high risk of damage to healthy tissues, such as bone loss and increased risk of fractures. The aim of the present study was to establish a rat model of local and systemic bone injury by focal irradiation, in order to study the etiological mechanism and intervention. The proximal metaphyseal region of the left hindlimb of male Sprague­Dawley rats were exposed to a single 2 Gy or three 8 Gy doses delivered on days 1, 3 and 5 using a small animal irradiator, the changes in bone volume and microarchitecture were evaluated, and the mineral apposition rate (MAR) was assessed. Furthermore, bone marrow­derived macrophages (BMMs) were isolated and induced to osteoclasts. It has been demonstrated that a single dose of 2 Gy may result in a significant loss of lumbar bone density at 3 days post­irradiation, however this is restored at 30 days post­irradiation. In the 3x8 Gy irradiation rat model, there was a rapid decrease in the aBMD of lumbar spine at 3 days and at 7 days post­irradiation, and the aBMD decline persisted even at 60 days post­irradiation. In addition, microCT analysis revealed a persistent decline in bone volume and damage in microarchitecture in the 3x8 Gy irradiation model, accompanied by a decrease in MAR, index of the decline in bone­forming ability. In the cellular mechanism, a single 2 Gy local irradiation mainly manifested as an enhancement of the BMMs osteoclastogenesis potential, which was different from the osteoclastogenesis inhibition after high­dose focal irradiation (3x8 Gy). In summary, the irradiation with simulated clinical focal fractionated radiotherapy exerts short­ and long­term systemic injury on bone tissue, characterized by different osteoclastogenesis potential between the high dose mode and a single 2 Gy focal irradiation. Physicians must consider the irreversibility of bone damage in clinical radiotherapy.


Assuntos
Densidade Óssea/efeitos da radiação , Reabsorção Óssea/genética , Osso e Ossos/metabolismo , Osteoclastos/efeitos da radiação , Animais , Densidade Óssea/genética , Reabsorção Óssea/patologia , Osso e Ossos/lesões , Osso e Ossos/efeitos da radiação , Relação Dose-Resposta à Radiação , Humanos , Exposição à Radiação , Ratos , Ratos Sprague-Dawley , Microtomografia por Raio-X
6.
Bone Joint J ; 101-B(9): 1151-1159, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31474143

RESUMO

AIMS: We analyzed the long-term outcomes of patients observed over ten years after resection en bloc and reconstruction with extracorporeal irradiated autografts. PATIENTS AND METHODS: This retrospective study included 27 patients who underwent resection en bloc and reimplantation of an extracorporeal irradiated autograft. The mean patient age and follow-up period were 31.7 years (9 to 59) and 16.6 years (10.3 to 24.3), respectively. The most common diagnosis was osteosarcoma (n = 10), followed by chondrosarcoma (n = 6). The femur (n = 13) was the most frequently involved site, followed by the tibia (n = 7). There were inlay grafts in five patients, intercalary grafts in 15 patients, and osteoarticular grafts in seven patients. Functional outcome was evaluated with the Musculoskeletal Tumor Society (MSTS) scoring system. RESULTS: There were no recurrences in the irradiated autograft and the autograft survived in 24 patients (88.9%). Major complications included nonunion (n = 9), subchondral bone collapse (n = 4), and deep infection (n = 4). Although 34 revision procedures were performed, 25 (73.5%) and four (11.8%) of these were performed less than five years and ten years after the initial surgery, respectively. The mean MSTS score at the last follow-up was 84.3% (33% to 100%). CONCLUSION: Considering long-term outcomes, extracorporeal irradiated autograft is an effective method of reconstruction for malignant musculoskeletal tumours Cite this article: Bone Joint J 2019;101-B:1151-1159.


Assuntos
Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/cirurgia , Osso e Ossos/cirurgia , Salvamento de Membro/métodos , Reimplante , Transplante Autólogo/métodos , Adolescente , Adulto , Autoenxertos/efeitos da radiação , Osso e Ossos/efeitos da radiação , Criança , Seguimentos , Sobrevivência de Enxerto , Humanos , Pessoa de Meia-Idade , Radioterapia/métodos , Procedimentos Cirúrgicos Reconstrutivos/métodos , Recuperação de Função Fisiológica , Estudos Retrospectivos , Transplante Autólogo/efeitos adversos , Adulto Jovem
7.
Electromagn Biol Med ; 38(3): 210-217, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31155966

RESUMO

There is a basic consensus on the biological effects of pulsed electromagnetic fields (PEMFs) on bone formation and bone reconstruction. PEMFs have been widely used in clinical treatment of osteoporosis, bone nonunion and delayed fracture healing. PEMFs is an intervention method of physiotherapy in vitro. In order to optimize the effect of PEMFs intervention, this study combined with the orthopedics clinic to construct a static magnetic intramedullary implant using NdFeB magnets as components. At the same time, it combines external-pulsed electromagnetic field to achieve locally targeted magnetic microenvironment. Rabbits were randomly divided into a combined magnetic field group (Implantation of static magnetic intramedullary implant in vivo combined with external-pulsed electromagnetic field), pulsed electromagnetic field group and control group. Micro CT and histopathology were used to estimate the effect of each group on bone formation and reconstruction in the early stage (5 weeks) of bone defect repair. Our data showed that the combined magnetic field group had relatively better new bone volume and trabecular structure in the bone defect area. The results showed that the combined magnetic field intervention method was feasible and had relatively preferably osteogenesis promoting effect. This study provides a new idea of magnetic field intervention, and also preliminarily verifies the feasibility of adding magnetic field to traditional orthopedic implant materials. However, the magnetic field strength of implanted materials still needs to be further refined.


Assuntos
Osso e Ossos/efeitos da radiação , Campos Eletromagnéticos , Imãs , Próteses e Implantes , Animais , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Osso e Ossos/fisiopatologia , Osteogênese/efeitos da radiação , Coelhos , Microtomografia por Raio-X
8.
Health Phys ; 117(2): 202-210, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31219902

RESUMO

The skeleton is one of the major retention sites for internally deposited actinides. Thus, an accurate estimation of the total skeleton content of these elements is important for biokinetic modeling and internal radiation dose assessment. Data from 18 whole-body donations to the US Transuranium and Uranium Registries with known plutonium intakes were used to develop a simple and reliable method for estimation of plutonium and Am activity in the total skeleton from single-bone analysis. A coefficient of deposition Kdep, defined as the ratio of actinide content in the patella to that in the skeleton, was calculated for Pu, Pu, and Am. No statistical difference was found in Kdep values among these radionuclides. Variability in Kdep values was investigated with relation to skeleton pathology (osteoporosis). The average Kdep of 0.0051 ± 0.0009 for the osteoporotic group was statistically different from Kdep of 0.0032 ± 0.0010 for nonosteoporotic individuals. The use of Kdep allows for rapid estimation of the total skeletal content of plutonium and Am with up to 35% uncertainty. To improve accuracy and precision of total skeleton activity estimates, regression analysis with power function was applied to the data. Strong correlation (r > 0.9) was found between Pu, Pu, and Am activities measured in the patella bone and total skeleton activity. The results of this study are specifically important for the optimization of bone sample collection for US Transuranium and Uranium Registries partial-body donations.


Assuntos
Amerício/análise , Osso e Ossos/metabolismo , Doenças Profissionais/metabolismo , Exposição Ocupacional/análise , Osteoporose/metabolismo , Plutônio/análise , Idoso , Idoso de 80 Anos ou mais , Amerício/envenenamento , Osso e Ossos/efeitos da radiação , Estudos de Casos e Controles , Humanos , Masculino , Doenças Profissionais/etiologia , Doenças Profissionais/patologia , Exposição Ocupacional/efeitos adversos , Osteoporose/etiologia , Osteoporose/patologia , Plutônio/envenenamento , Doadores de Tecidos
9.
Semin Nucl Med ; 49(4): 313-325, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31227054

RESUMO

The current mainstay of treatment in metastatic prostate cancer is based on hormonal manipulations. Standard androgen deprivation therapy and novel androgen axis drugs are commonly well tolerable and can stabilize metastatic hormone-sensitive prostate cancers for years. However, metastatic castration-resistant prostate cancer is still challenging to treat. Except taxanes, prostate cancer presents intrinsic resistance against conventional chemotherapies. The typically elderly patient population excludes more aggressive treatment regimens. First clinical trials evaluating immunotherapy or tyrosine-kinase-inhibitors against prostate cancer failed. In contrast, prostate cancer can be radiosensitive and external beam radiotherapy is effective in localized prostate cancer, thus providing a good rationale for the use of systemic radiopharmaceuticals in the metastatic setting. Beta-particle emitting "bone-seekers" have a long history and are effective as analgesics but do not improve survival because they are limited by red-marrow dose. Alpha emitting 223Radium can be used in a dose that prolongs survival but is restricted to bone-confined patients. Currently radiolabeled high-affinity ligands to the prostate-specific membrane antigen are in clinical evaluation. While radioimmunotherapy approaches were limited by the long circulation time and slow tumor-accumulation of antibodies, low molecular weight PSMA-specific ligands offer an approx. ten-fold improved tumor to red-marrow ratio in comparison to the unspecific bone-seekers. Early clinical studies demonstrate that regarding surrogate markers, such as >50% PSA reduction (60%) and radiologic response (80%), PSMA-therapy exceeds the antitumor activity of all approved or other recently tested compounds; for example, PSA-response was only observed in approx. a total of 10% of patients treated with ipilimumab, sunitinib, cabozantinib, or xofigo, respectively and in approx. 30, 40, 50% of patients treated with abiraterone, cabazitaxel, or enzalutamide. Also progression free and overall survivals of these single-arm studies appear promising when compared to historical controls. Consecutively, the first PSMA-RLT recently advanced into phase-3 (177Lu-PSMA-617; VISION-trial). Future developments aim to avoid off-target radiation by ligand-optimization and to outperform the antitumor activity of beta-emitter PSMA-RLT by labeling with highly focused, high energy transferring alpha-nuclides; however the latter potentially also increasing the risk of side-effects and additional early phase studies are needed to improve treatment protocols. Academically clinical research is developing prognostic tools to improve treatment benefit by selecting the most appropriate patients in advance.


Assuntos
Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia , Antígenos de Superfície/metabolismo , Osso e Ossos/efeitos da radiação , Glutamato Carboxipeptidase II/metabolismo , Humanos , Masculino , Metástase Neoplásica , Prognóstico , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/metabolismo
10.
PLoS One ; 14(5): e0216934, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31136607

RESUMO

BACKGROUND: Radium-223 is a targeted alpha-particle therapy that improves survival in men with metastatic castration resistant prostate cancer (mCRPC), particularly in men with elevated serum levels of bone alkaline phosphatase (B-ALP). We hypothesized that osteomimicry, a form of epithelial plasticity leading to an osteoblastic phenotype, may contribute to intralesional deposition of radium-223 and subsequent irradiation of the tumor microenvironment. METHODS: We conducted a pharmacodynamic study (NCT02204943) of radium-223 in men with bone mCRPC. Prior to and three and six months after radium-223 treatment initiation, we collected CTCs and metastatic biopsies for phenotypic characterization and CTC genomic analysis. The primary objective was to describe the impact of radium-223 on the prevalence of CTC B-ALP over time. We measured radium-223 decay products in tumor and surrounding normal bone during treatment. We validated genomic findings in a separate independent study of men with bone metastatic mCRPC (n = 45) and publicly accessible data of metastatic CRPC tissues. RESULTS: We enrolled 20 men with symptomatic bone predominant mCRPC and treated with radium-223. We observed greater radium-223 radioactivity levels in metastatic bone tumor containing biopsies compared with adjacent normal bone. We found evidence of persistent Cellsearch CTCs and B-ALP (+) CTCs in the majority of men over time during radium-223 therapy despite serum B-ALP normalization. We identified genomic gains in osteoblast mimicry genes including gains of ALPL, osteopontin, SPARC, OB-cadherin and loss of RUNX2, and validated genomic alterations or increased expression at the DNA and RNA level in an independent cohort of 45 men with bone-metastatic CRPC and in 150 metastatic biopsies from men with mCRPC. CONCLUSIONS: Osteomimicry may contribute in part to the uptake of radium-223 within bone metastases and may thereby enhance the therapeutic benefit of this bone targeting radiotherapy.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Ósseas/radioterapia , Terapia de Alvo Molecular/métodos , Neoplasias de Próstata Resistentes à Castração/radioterapia , Rádio (Elemento)/uso terapêutico , Idoso , Fosfatase Alcalina/sangue , Fosfatase Alcalina/genética , Biomarcadores Tumorais/metabolismo , Biópsia , Neoplasias Ósseas/genética , Neoplasias Ósseas/mortalidade , Neoplasias Ósseas/secundário , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Osso e Ossos/efeitos da radiação , Caderinas/genética , Caderinas/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Progressão da Doença , Expressão Gênica , Humanos , Masculino , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Células Neoplásicas Circulantes/efeitos da radiação , Osteonectina/genética , Osteonectina/metabolismo , Osteopontina/genética , Osteopontina/metabolismo , Próstata/metabolismo , Próstata/patologia , Próstata/efeitos da radiação , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/mortalidade , Neoplasias de Próstata Resistentes à Castração/patologia , Rádio (Elemento)/sangue , Rádio (Elemento)/farmacocinética , Análise de Sobrevida , Microambiente Tumoral/genética , Microambiente Tumoral/efeitos da radiação
11.
Anticancer Res ; 39(5): 2607-2614, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31092459

RESUMO

BACKGROUND/AIM: To evaluate our initial experience with radium-223 chloride (Ra-223). MATERIALS AND METHODS: A total of 26 castration-resistant prostate cancer (CRPC) patients with bone metastases, treated with Ra-223 at our hospital were evaluated. This study aimed to observe adverse events (AEs) and changes in serum markers, and Bone Scan Index (BSI). Additionally, the relationship between these values and OS was investigated. RESULTS: The observed AEs mainly included fatigue and nausea. Alkaline phosphatase (ALP) and bone-type alkaline phosphatase (BAP) levels decreased following the treatment; however, those of PSA and 1-CTP tended to increase, regardless of Ra-223 administration. Overall survival (OS) was significantly improved in cases with a baseline BSI value of <2 compared with those with a baseline BSI value of ≥2. Moreover, the decrease in BSI after administration of Ra-223 was an independent factor, significantly prolonging OS. CONCLUSION: ALP and BAP levels and BSI values are suitable evaluation markers during treatment with Ra-223. Also, baseline BSI values and the decrease in BSI following treatment are independent factors predicting OS.


Assuntos
Neoplasias Ósseas/radioterapia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Neoplasias de Próstata Resistentes à Castração/radioterapia , Rádio (Elemento)/administração & dosagem , Idoso , Fosfatase Alcalina/sangue , Neoplasias Ósseas/sangue , Neoplasias Ósseas/patologia , Neoplasias Ósseas/secundário , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/efeitos da radiação , Intervalo Livre de Doença , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/sangue , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Humanos , Masculino , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/patologia , Resultado do Tratamento
12.
Radiother Oncol ; 137: 77-82, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31078014

RESUMO

BACKGROUND AND PURPOSE: To determine whether bone matching (BM) or marker matching (MM) is the better positioning technique for carbon ion radiotherapy (CIRT) of primary hepatocellular carcinoma (HCC), we prospectively evaluated accumulated dose distributions with respect to intra- and inter-fractional anatomical changes. MATERIALS AND METHODS: The accumulated doses in ten patients with HCC were evaluated, with the doses being calculated with respect to inter-fractional changes (InterDose) on treatment-room CT images on day 1 or day 2 of therapy (RefCT). This was accomplished by warping 3-day CT dose distributions to the RefCT through deformable registration. The accumulated doses were also calculated with respect to intra-fractional change (IntraDose) calculated by warping dose distributions for three 4DCT phases to the RefCT. Each dose was evaluated using dose-volume parameters for the clinical target volume (CTV) percentages receiving greater than 95% of the prescription dose (V95). RESULTS: The InterDose CTV V95 values (mean [range]) were BM: 98.74% (95.62-100%), MM: 99.79% (98.55-100%), and the IntraDose values were BM: 99.46% (98.10-100%), MM: 99.74% (98.91-100%). Although all cases were acceptable with either matching method, MM provided better values than BM. CONCLUSION: MM is a better positioning technique than BM for ensuring the target dose during and between fractions of CIRT. However, further analysis is required as our study included only a low number of cases.


Assuntos
Osso e Ossos/efeitos da radiação , Carcinoma Hepatocelular/radioterapia , Radioterapia com Íons Pesados/métodos , Neoplasias Hepáticas/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Idoso , Idoso de 80 Anos ou mais , Osso e Ossos/diagnóstico por imagem , Carcinoma Hepatocelular/diagnóstico por imagem , Feminino , Marcadores Fiduciais , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica
13.
Nucl Med Commun ; 40(6): 588-596, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30908340

RESUMO

OBJECTIVES: This work aims to assess whether the biochemical response of radium-223-dichloride treatment can be predicted based on the pretherapy bone scan, and consequently if bone scan index (BSI) and maximum lesion intensity have a place as alternatives or as complements to extent of bone disease (EOBD) scoring in predicting biochemical response to treatment. Many cases of advanced prostate cancer have evidence of bone metastasis. Accurate EOBD quantification could help predict the response to radium-223-dichloride therapy. Current EOBD score is simple to use but does not consider size, intensity or localisation of lesion BSI might be more suitable for stratification of bone metastases. PATIENTS AND METHODS: Bone scans (n=20) preceding radium-223-dichloride treatment for prostate cancer were assessed retrospectively using automated BSI software (EXINI) and by assessing maximum counts per lesion. Results were then compared to total alkaline phosphatase (ALP) as a measure of biochemical response to therapy using linear regressions and to their EOBD scores using box plot analysis. RESULTS: Moderate correlation was found between ALP response and maximum lesion intensity (R=0.41) and BSI (R=0.46). Strong correlation (R=0.71) was found between baseline ALP and BSI and between lesion number and BSI (R=0.60). Visual assessment of EOBD score was found to correlate well with baseline ALP and maximum ALP response. CONCLUSION: BSI is a useful asset in stratification of patients with metastatic bone disease. It may also have a place in prediction of biochemical response.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/radioterapia , Osso e Ossos/diagnóstico por imagem , Rádio (Elemento)/uso terapêutico , Fosfatase Alcalina/metabolismo , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/secundário , Osso e Ossos/efeitos da radiação , Humanos , Masculino , Neoplasias da Próstata/patologia , Radioisótopos/uso terapêutico , Estudos Retrospectivos , Resultado do Tratamento
14.
Radiat Res ; 191(5): 413-427, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30870097

RESUMO

Total-body irradiation (TBI) followed by transfer of bone marrow cells from donors is routinely performed in immunology research and can be used to manipulate differentiation and/or function of bone cells. However, exposure to high-dose radiation can result in irreversible osteopenia, and transfer of heterogeneous cell populations can complicate interpretation of results. The goal of this research was to establish an approach for reconstituting bone marrow using small numbers of purified donor-derived hematopoietic stem cells (HSCs) without negatively affecting bone metabolism. Gamma-irradiated (9 Gy) WBB6F1 mice were engrafted with bone marrow cells (5 × 106 cells) or purified HSCs (3,000 cells) obtained from GFP transgenic mice. In vivo analysis and in vitro differentiation assays performed two months later established that both methods were effective in reconstituting the hematopoietic compartment with donor-derived cells. We confirmed these findings by engrafting C57Bl/6 (B6) mice with bone marrow cells or purified HSCs from CD45.1 B6 congenic mice. We next performed adoptive transfer of purified HSCs (750 cells) into WBB6F1 and radiosensitive KitW/W-v mice and evaluated the skeleton two months later. Minimal differences were observed between controls and WBB6F1-engrafted mice that received fractionated doses of 2 × 5 Gy. Kitw/wv mice lost weight and became osteopenic after 2 × 5 Gy irradiations but these abnormalities were negligible after 5 Gy irradiation. Importantly, adoptive transfer of wild-type cells into Kitw/wv mice restored normal Kit expression in bone marrow. Together, these findings provide strong evidence for efficient engraftment with purified HSCs after lethal TBI with minimal collateral damage to bone. This approach will be useful for investigating mechanisms by which hematopoietic lineage cells regulate bone metabolism.


Assuntos
Osso e Ossos/patologia , Osso e Ossos/efeitos da radiação , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Animais , Osso e Ossos/metabolismo , Contagem de Células , Feminino , Regulação da Expressão Gênica/efeitos da radiação , Camundongos , Camundongos Endogâmicos C57BL , Tamanho do Órgão/efeitos da radiação , Osteocalcina/sangue
15.
Radiographics ; 39(2): 344-366, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30844346

RESUMO

Radiation therapy is one of the cornerstones for the treatment of thoracic malignancies. Although advances in radiation therapy technology have improved the delivery of radiation considerably, adverse effects are still common. Postirradiation changes affect the organ or tissue treated and the neighboring structures. Advances in external-beam radiation delivery techniques and how these techniques affect the expected thoracic radiation-induced changes are described. In addition, how to distinguish these expected changes from complications such as infection and radiation-induced malignancy, and identify treatment failure, that is, local tumor recurrence, is reviewed. ©RSNA, 2019.


Assuntos
Mama/efeitos da radiação , Coração/efeitos da radiação , Pulmão/efeitos dos fármacos , Neoplasias Induzidas por Radiação/diagnóstico por imagem , Lesões por Radiação/diagnóstico por imagem , Radiografia/métodos , Radioterapia/efeitos adversos , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/efeitos da radiação , Mama/diagnóstico por imagem , Feminino , Coração/diagnóstico por imagem , Humanos , Pulmão/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Linfonodos/efeitos da radiação , Masculino , Doses de Radiação , Lesões por Radiação/etiologia , Radioterapia/métodos , Tomografia Computadorizada por Raios X
16.
Health Phys ; 116(5): 590-598, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30624351

RESUMO

Portable x-ray fluorescence devices have grown in popularity for possible metal exposure assessment using in vivo measurements of bone and toenail. These measurements are accompanied by a small radiation dose, which is typically assessed by radiation safety committees to be minimal. However, an understanding of precise dose under different instrument conditions is still needed. This study set out to do a thorough investigation of the exact dose measurements using optically stimulated dosimeters, thermoluminescent dosimeters, and simulation with a Monte Carlo N-Particle transport code to assess the skin and total-body effective dose typical of portable x-ray fluorescence devices. We showed normal linear relationships between measurement time, x-ray tube current, and radiation dose with the device, and we showed a second order polynomial relationship with increasing voltage and radiation dose. Dose was quantified using thermoluminescent dosimeters, optically stimulated dosimeters, and simulations, which gave similar dose estimations. Skin dose for a standard 50-kV, 40-µA measurement for bone and toenail in vivo was 48.5 and 28.7 mSv, respectively, according to simulation results. Total-body effective dose was shown as 3.4 and 2.0 µSv for in vivo bone and toenail measurements, respectively, for adults using the portable x-ray fluorescence device.


Assuntos
Osso e Ossos/efeitos da radiação , Fluorescência , Metais/análise , Unhas/efeitos da radiação , Imagens de Fantasmas , Radiometria/métodos , Dosimetria Termoluminescente/métodos , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Método de Monte Carlo , Doses de Radiação , Pele/efeitos da radiação
17.
Radiat Oncol ; 14(1): 15, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30670063

RESUMO

BACKGROUND: The aim of this study was to evaluate the ionizing radiation (IR) effects on rat bone 30 and 60 days after irradiation. METHODS: Wistar rats were submitted to IR (30 Gy) on the left leg and were euthanized after 30 and 60 days. The legs were divided into four groups according to the treatment and euthanization time: C30 and C60 (right leg-without IR), IR30 and IR60 (left leg-with IR). RESULTS: CT analysis showed more radiodensity in C60 compared with other groups, and IR60 showed more radiodensity than IR30. In histomorphometric analysis, C30 showed lower bone matrix values compared with IR30 and C60. Lacunarity analyses showed more homogeneous bone channel distribution in C30 than IR30. ATR-FTIR showed decrease in ratio of mature and immature crosslinks in IR30 compared with C30. Crystallinity Index was decrease in IR60 compared with C60. The Amide III + Collagen/HA ratio was increased in C60 compared with C30; however this ratio decreased in IR60 compared with IR30. Biomechanical analysis showed lower values in IR groups in both time. CONCLUSIONS: IR damaged bone quality and decreased stiffness. Moreover, the results suggested that the deleterious effects of IR increased in the late time points.


Assuntos
Osso e Ossos/efeitos da radiação , Radiação Ionizante , Animais , Fenômenos Biomecânicos , Colágeno/química , Masculino , Ratos , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Tomografia Computadorizada por Raios X
18.
Electromagn Biol Med ; 38(1): 1-20, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30661411

RESUMO

Stem cells are one of the most important sources to develope  a new strategy for repairing bone lesions through tissue engineering. Osteogenic differentiation of stem cells can be affected by various factors such as biological, chemical, physiological, and physical ones. The application of ELF-EMFs has been the subject of many research in bone tissue engineering and evidence suggests that this exogenous physical stimulus can promote osteogenic differentiation in several types of  cells. The purpose of this paper is to review the current knowledge on the effects of EMFs on stem cells in bone tissue engineering studies. We recapitulated and analyzed 39 articles that were focused on the application of EMFs for bone tissue engineering purposes. We tabulated scattered information from these articles for easy use and tried to provide an overview of conducted research and identify the knowledge gaps in the field.


Assuntos
Osso e Ossos/efeitos da radiação , Campos Eletromagnéticos , Medicina Regenerativa/métodos , Animais , Osso e Ossos/citologia , Campos Eletromagnéticos/efeitos adversos , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos da radiação , Engenharia Tecidual
19.
Int J Radiat Oncol Biol Phys ; 103(3): 669-679, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30414451

RESUMO

With the increasing use of advanced radiation techniques such as intensity modulated radiation therapy, stereotactic radiation therapy, and proton therapy, radiation oncologists now have the tools to mitigate radiation-associated toxicities. This is of utmost importance in the treatment of a pediatric patient. To best use these advanced techniques to mitigate radiation-induced growth abnormalities, the radiation oncologist should be equipped with a nuanced understanding of the anatomy of centers of growth. This article aims to enable the radiation oncologist to better understand, predict, and minimize radiation-mediated toxicities on growth. We review the process of bone development and radiation-induced growth abnormalities and provide an atlas for contouring important growth plates to guide radiation treatment planning. A more detailed recognition of important centers of growth may improve future treatment outcomes in children receiving radiation therapy.


Assuntos
Osso e Ossos/efeitos da radiação , Neoplasias/radioterapia , Lesões por Radiação , Compostos Radiofarmacêuticos , Radioterapia/métodos , Encéfalo/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Sobreviventes de Câncer , Criança , Transtornos do Crescimento/etiologia , Humanos , Neoplasias/complicações , Órgãos em Risco , Pediatria , Terapia com Prótons/efeitos adversos , Terapia com Prótons/métodos , Radioterapia (Especialidade)/métodos , Radiocirurgia , Radioterapia/efeitos adversos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Tomografia Computadorizada por Raios X
20.
Clin Oral Investig ; 23(6): 2785-2793, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30368663

RESUMO

OBJECTIVES: This study aimed to evaluate the effects of radiotherapy on biomechanical, histomorphometric, and microstructural characteristics of bone, in diverse periods, compared with intact bone tissue. MATERIALS AND METHODS: Eighteen adult male New Zealand rabbits were treated with a single radiation dose of 30 Gy. The animals were randomly divided into six groups: NoIr, control group, no radiation, and five irradiated groups sacrificed after 24 h (Ir24h), 7 (Ir7d), 14 (Ir14d), 21 (Ir21d), and 28 (Ir28d) days. After these periods, the animals were sacrificed and their tibias (n = 6) evaluated using three-point bending test to calculate the ultimate force, work to failure, and bone stiffness. Dynamic indentation test was used to quantify Vickers hardness and elasticity modulus of bone tissue. Micro-CT was used to analyze the cortical volume (CtV), cortical thickness (CtTh), and porosity (Ct.Po). Histomorphometric assessment was based on the lacunarity of bone tissue. Data were analyzed using one-way ANOVA and Kruskal-Wallis tests followed by Tukey, Dunnet, and Dunn's post-tests (P < 0.05). RESULTS: The ultimate force, work to failure, stiffness, elastic modulus, and Vickers hardness values of irradiated bone were significantly lower that non-irradiated bone. Irradiated bone showed significantly lower CtTh and CtV values and higher CtPo than non-irradiated bone. No significant difference was found for lacunarity between non-irradiated bone and irradiated bone. CONCLUSIONS: Ionizing radiation decreases normal anisotropy on microarchitecture of cortical bone, and increases bone fragility compared with non-irradiated bone. Further, these changes were seen after longer periods (e.g., 14 and 21 days), and not immediately after radiation therapy. CLINICAL RELEVANCE: The radiotherapy reduces bone mechanical properties and the normal structure of organic and inorganic bone matrix. For studying the protocols to protect the radiotherapy effect using rabbit model, the use of the sacrificing period between 14 and 21 days is recommended.


Assuntos
Osso e Ossos/efeitos da radiação , Radiação Ionizante , Radioterapia/efeitos adversos , Animais , Fenômenos Biomecânicos , Osso e Ossos/patologia , Módulo de Elasticidade , Masculino , Coelhos , Distribuição Aleatória , Tíbia , Microtomografia por Raio-X
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