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2.
Telemed J E Health ; 30(4): 963-975, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38052050

RESUMO

Introduction: Remote learners and educators face geographic, professional, and personal barriers that affect their access to quality ultrasound education. The integration of telehealth in ultrasound education enables learners performing ultrasound to receive real-time instruction from an educator at a distant or remote site. However, to date, there has been poor understanding of the efficacy, benefits, shortcomings, and economic impact of telehealth education in comparison to in-person ultrasound training. The aim of this research was to assess current literature on telehealth in ultrasound education and hands-on training, its outcomes and impact, and requirements for future development. Methods: This review examined international literature on telehealth in ultrasound training. The primary author and second investigator were involved in the research and reached consensus on the eligibility criteria, search strategy, included articles, data extraction, and quality assessment. Results: A total of 23 studies were obtained from Medline, Emcare and Scopus. Key themes identified: Most studies saw an equivalent improvement in knowledge and skills through pre and postassessments in both in-person and telehealth sessions. Generally, learners felt comfortable performing ultrasound guided by a remote educator and felt their skills had been advanced across all studies. Educators reported positive feedback, however compared with learners, educators expressed less satisfaction with the telehealth session. Conclusions: This study demonstrated the feasibility of telehealth in ultrasound training for remote learners with little to no experience. Quality studies with comparable outcomes are needed to ascertain the safe and effective application of telehealth in ultrasound training.


Assuntos
Telemedicina , Humanos , Escolaridade , Emoções , Cuidados Paliativos , Competência Clínica
3.
Int J Mol Sci ; 25(4)2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38396904

RESUMO

Accurately characterizing DNA double-stranded breaks (DSBs) and understanding the DNA damage response (DDR) is crucial for assessing cellular genotoxicity, maintaining genomic integrity, and advancing gene editing technologies. Immunofluorescence-based techniques have proven to be invaluable for quantifying and visualizing DSB repair, providing valuable insights into cellular repair processes. However, the selection of appropriate markers for analysis can be challenging due to the intricate nature of DSB repair mechanisms, often leading to ambiguous interpretations. This comprehensively summarizes the significance of immunofluorescence-based techniques, with their capacity for spatiotemporal visualization, in elucidating complex DDR processes. By evaluating the strengths and limitations of different markers, we identify where they are most relevant chronologically from DSB detection to repair, better contextualizing what each assay represents at a molecular level. This is valuable for identifying biases associated with each assay and facilitates accurate data interpretation. This review aims to improve the precision of DSB quantification, deepen the understanding of DDR processes, assay biases, and pathway choices, and provide practical guidance on marker selection. Each assay offers a unique perspective of the underlying processes, underscoring the need to select markers that are best suited to specific research objectives.


Assuntos
Quebras de DNA de Cadeia Dupla , Dano ao DNA , DNA/metabolismo , Reparo do DNA , Reparo do DNA por Junção de Extremidades
4.
BMC Public Health ; 23(1): 2268, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37978505

RESUMO

BACKGROUND: Ultrasound is the primary diagnostic tool in pregnancy, capable of identifying high-risk pregnancies and life-threatening conditions, allowing for appropriate management to prevent maternal and fetal morbidity and mortality. Women and babies from rural and remote Australia and low-resource areas worldwide experience poorer health outcomes and barriers to accessing antenatal care and imaging services. Healthcare clinicians working in these regions face significant challenges practising with limited resources and accessing training opportunities. OBJECTIVE: To perform an exploratory needs-analysis survey investigating the availability, accessibility and use of antenatal ultrasound in rural Australia, exploring rural clinicians' interest in and access to ultrasound training opportunities. METHODS: The survey tool for this cross-sectional study was designed and distributed as an anonymous online questionnaire targeting healthcare clinicians (doctors, nurses, midwives, clinic managers, Aboriginal healthcare workers) providing antenatal care in rural regions. Descriptive analysis was applied to quantitative data and thematic analysis was used to explore qualitative components. RESULTS: A total of 114 valid survey responses were analysed. Overall, 39% (43/111) reported ultrasound was not used when providing antenatal care to patients at their clinic, stating 'Lack of ultrasound equipment (73%,29/40) and inaccessibility of training opportunities (47%,19/40) as the main reasons. For those with ultrasound (61%,68/111), estimating due date (89%,57/64) was the main use, and limited training/skills to operate the equipment (59%,38/64) and inaccessibility/distance of training opportunities (45%,29/64) were the most commonly reported barriers. Clinicians described a lack of childcare options (73%,74/102), long distances to reach ultrasound services (64%,65/102), appointment (59%,60/102) and transport availability/times (46%,47/102) as the main obstacles to patient access. Increased attendance, compliance with care directives, parental bonding and improved lifestyle choices were described by respondents as positive outcomes of antenatal ultrasound use. CONCLUSIONS: Future efforts to combat inequitable service access must adopt a coordinated approach to meet the needs of pregnant women in low-resource settings. Providing portable ultrasound equipment, training in antenatal Point-of-Care ultrasound (PoCUS) with ongoing support/mentoring and accreditation of health professionals could strengthen rural workforce capacity. This, along with addressing the complex economic, environmental and socio-cultural barriers faced by patients, could improve service access and pregnancy outcomes in rural and remote communities.


Assuntos
Serviços de Saúde Rural , Humanos , Feminino , Gravidez , Austrália , Estudos Transversais , Inquéritos e Questionários , Atenção à Saúde
5.
J Ultrasound Med ; 42(6): 1193-1209, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36409651

RESUMO

Endometriosis is a common and painful gynaecological condition that takes an average of 6.4years to diagnose. While laparoscopic surgery is the recommend gold standard in diagnosis of endometriosis, transvaginal ultrasound (TVS) is able to assist surgeons in the planning and management of patients, especially when there is limited visualisation in the posterior compartment. Uterosacral ligaments (USL) are located in the posterior compartment and are one of the first and most common places that endometriosis deposits, The International Deep Endometriosis Analysis (IDEA) group consensus, which are the current guidelines for DE imaging, recommends a thorough ultrasound assessment to identify endometriotic disease. This includes an assessment of anatomic structures in the posterior compartment including the USLs. However, IDEA does not explicitly articulate specifics of USL imaging and measurements on ultrasound. The primary aim of this review is to determine is to identify ultrasound techniques and characteristics of USLs in the diagnosis of deep infiltrative endometriosis (DE). The secondary aim is to describe and summarise these findings into normal and pathological findings. A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A population, interventions, comparator, and outcome framework was used to define a search strategy. Articles were screened using Covidence review management system, and data was extracted by two authors using a standardised and piolet-tested form. Quality assessment was conducted using the Critical Appraisal Skills Programme (CASP). Medline, Embase and Scopus and Google Scholar were searched yielding 250 articles, with 22 being included in the review. Analysis of the data demonstrated inconsistent reporting of ultrasound techniques and characteristics of USLs. Most (20/22) papers described abnormal criteria of USLs, only 5/22 papers determined what the normal USL appearance is or what techniques (11/22) were applied. Even though reporting was heterogeneous, there was a high level of tertiary centre participation with gynaecological experienced operators, therefore was a high level of agreement. Through review of the current literature, this study has investigated ultrasound techniques and characteristics of USLs for the diagnosis of DE. All papers included in this review reported presence of pathological sonographic findings of the USLs when DE was presented therefore it is recommended that USL examination become a part of TVS exams when DE is clinically suspected. This study also demonstrated that there was lack of data and no agreement when it comes to measuring USLs with DE. Even so, the current evidence demonstrates that scanning the USLs, and locating, identifying, and describing USL thickening and endometriotic nodules in the various locations using the described techniques and characteristics in this review has clinical value in early diagnosis.


Assuntos
Endometriose , Feminino , Humanos , Endometriose/diagnóstico por imagem , Sensibilidade e Especificidade , Útero/patologia , Ultrassonografia/métodos , Ligamentos/diagnóstico por imagem , Ligamentos/patologia
6.
Int J Mol Sci ; 24(2)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36675033

RESUMO

Cancer stem cells are known to play a key role in tumour development, proliferation, and metastases. Their unique properties confer resistance to therapy, often leading to treatment failure. It is believed that research into the identification, targeting, and eradication of these cells can revolutionise oncological treatment. Based on the principle that what cannot be seen, cannot be targeted, a primary step in cancer management is the identification of these cells. The current review aims to encompass the state-of-the-art functional imaging techniques that enable the identification of cancer stem cells via various pathways and mechanisms. The paper presents in vivo molecular techniques that are currently available or await clinical implementation. Challenges and future prospects are highlighted to open new research avenues in cancer stem cell imaging.


Assuntos
Neoplasias , Tomografia por Emissão de Pósitrons , Humanos , Tomografia por Emissão de Pósitrons/métodos , Neoplasias/diagnóstico por imagem , Células-Tronco Neoplásicas , Imagem Molecular/métodos , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos
7.
Int J Mol Sci ; 24(24)2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38139085

RESUMO

Tumour repopulation during treatment is a well acknowledged yet still challenging aspect of cancer management. The latest research results show clear evidence towards the existence of cancer stem cells (CSCs) that are responsible for tumour repopulation, dissemination, and distant metastases in most solid cancers. Cancer stem cell quiescence and the loss of asymmetrical division are two powerful mechanisms behind repopulation. Another important aspect in the context of cancer stem cells is cell plasticity, which was shown to be triggered during fractionated radiotherapy, leading to cell dedifferentiation and thus reactivation of stem-like properties. Repopulation during treatment is not limited to radiotherapy, as there is clinical proof for repopulation mechanisms to be activated through other conventional treatment techniques, such as chemotherapy. The dynamic nature of stem-like cancer cells often elicits resistance to treatment by escaping drug-induced cell death. The aims of this scoping review are (1) to describe the main mechanisms used by cancer stem cells to initiate tumour repopulation during therapy; (2) to present clinical evidence for tumour repopulation during radio- and chemotherapy; (3) to illustrate current trends in the identification of CSCs using specific imaging techniques; and (4) to highlight novel technologies that show potential in the eradication of CSCs.


Assuntos
Neoplasias , Humanos , Neoplasias/terapia , Divisão Celular , Células-Tronco Neoplásicas , Morte Celular
8.
Eur J Appl Physiol ; 122(6): 1397-1408, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35296909

RESUMO

Exercise improves measures of cardiovascular (CV) health and function. But as traditional measures improve gradually, it can be difficult to identify the effectiveness of an exercise intervention in the short-term. Left ventricular global longitudinal strain (LVGLS) is a highly sensitive CV imaging measure that detects signs of myocardial dysfunction prior to more traditional measures, with reductions in LVGLS a strong prognostic indicator of future CV dysfunction and mortality. Due to its sensitivity, LVGLS may offer useful method of tracking the effectiveness of an exercise intervention on CV function in the short-term, providing practitioners useful information to improve patient care in exercise settings. However, the effect of exercise on LVGLS is unclear. This systematic review and meta-analysis aimed to determine the effect exercise has on LVGLS across a range of populations. Included studies assessed LVGLS pre-post an exercise intervention (minimum 2 weeks) in adults 18 years and over, and were published in English from 2000 onwards. Study-level random-effects meta-analyses were performed using Stata (v16.1) to calculate summary standardized mean differences (SMD) and 95% confidence intervals (CI). 39 studies met selection criteria, with 35 included in meta-analyses (1765 participants). In primary analyses, a significant improvement in LVGLS was observed in populations with CV disease (SMD = 0.59; 95% CI 0.16-1.02; p = 0.01), however, no significant effect of exercise was observed in CV risk factor and healthy populations. In populations with CV disease, LVGLS could be used as an early biomarker to determine the effectiveness of an exercise regime before changes in other clinical measures are observed.


Assuntos
Exercício Físico/fisiologia , Coração/fisiologia , Adolescente , Adulto , Humanos
9.
BMC Med Educ ; 22(1): 906, 2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36585662

RESUMO

BACKGROUND: There is limited access to life-saving antenatal ultrasound in low-resource rural and remote settings worldwide, including Australia, mainly due to shortages in skilled staff. Point-of-care ultrasound (PoCUS) offers a viable solution to this service deficit, however, rural clinicians face many barriers accessing training and professional development critical to advancing their clinical practice. Standards for PoCUS training and competency assessment are unclear. Regulation is lacking globally, allowing untrained and inexperienced clinicians to practice PoCUS clinically. METHODS: This prospective single cohort study aimed to evaluate antenatal PoCUS training workshops for General Practitioners (GPs) and Midwives/Nurses (M/Ns) from rural/remote Australia, assessing the impact of the training on trainees' knowledge, confidence and translation of PoCUS into clinical practice. Two-day antenatal ultrasound workshops were delivered at the University of South Australia (UniSA) in 2018 and 2019 to 41 rural/remote clinicians . The training was designed and evaluated using the New world Kirkpatrick Evaluation Framework. Sixteen GPs and 25 M/Ns with mixed prior ultrasound experience were funded to attend. The course consisted of lectures interspaced with hands-on training sessions using high-fidelity simulators and live pregnant models. Pre- and post-knowledge assessments were performed. Post-workshop evaluation and follow-up surveys (3- and 6-month post-training) assessed the workshops and changes to trainees' clinical practice. A 2-day follow-up training session was conducted 12 months after the workshops for 9 trainees. RESULTS: Pre/post knowledge testing demonstrated a 22% mean score improvement (95% CI 17.1 to 27.8, P < 0.0001). At 6 months, 62% of trainees were performing PoCUS that had assisted in patient management and clinical diagnosis, and 46% reported earlier diagnosis and changes to patient management. 74% of trainees had increased scanning frequency and 93% reported improved scanning confidence. CONCLUSION: This study demonstrated intensive 2-day workshops can equip clinicians with valuable antenatal PoCUS skills, offering a viable solution to assist in the assessment and management of pregnant women in the rural/resource-poor setting where access to ultrasound services is limited or non-existent. Geographical isolation and lack of onsite specialist supervision poses an ongoing challenge to the continuing professional development of remote trainees and the implementation of PoCUS.


Assuntos
Atenção à Saúde , Sistemas Automatizados de Assistência Junto ao Leito , Feminino , Humanos , Gravidez , Estudos Prospectivos , Estudos de Coortes , Ultrassonografia
10.
Int J Mol Sci ; 23(6)2022 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-35328787

RESUMO

The continuously evolving field of radiotherapy aims to devise and implement techniques that allow for greater tumour control and better sparing of critical organs. Investigations into the complexity of tumour radiobiology confirmed the high heterogeneity of tumours as being responsible for the often poor treatment outcome. Hypoxic subvolumes, a subpopulation of cancer stem cells, as well as the inherent or acquired radioresistance define tumour aggressiveness and metastatic potential, which remain a therapeutic challenge. Non-conventional irradiation techniques, such as spatially fractionated radiotherapy, have been developed to tackle some of these challenges and to offer a high therapeutic index when treating radioresistant tumours. The goal of this article was to highlight the current knowledge on the molecular and radiobiological mechanisms behind spatially fractionated radiotherapy and to present the up-to-date preclinical and clinical evidence towards the therapeutic potential of this technique involving both photon and proton beams.


Assuntos
Neoplasias , Radioterapia (Especialidade) , Fracionamento da Dose de Radiação , Humanos , Neoplasias/radioterapia , Fótons , Radiobiologia , Radioterapia
11.
J Ultrasound Med ; 39(8): 1477-1490, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32083336

RESUMO

Endometriosis is a common gynecologic condition affecting as many as 1 per 10 women. Transvaginal ultrasound (TVUS) has become a frontline tool in the diagnosis of deep infiltrating endometriosis (DIE) before surgery. The primary aim of this review was to determine the accuracy of TVUS for DIE. The secondary aim was to determine accuracy specifically when a sonographer performed the TVUS examination. A systematic review was performed, searching literature by following a population, intervention, comparator, and outcome outline. MEDLINE, Embase, Emcare, and Google Scholar were searched in July 2018 and in November 2019. Including "sonographer" in the search terms yielded no results, so our terms were expanded. Two hundred and four articles were returned from the searches, and 35 were ultimately included in the final review. Analysis of the returned articles revealed the TVUS is a valuable diagnostic tool for DIE before surgery. Sensitivities ranged from 78.5% to 85.3%, specificities from 46.1% to 92.5%, and accuracies from 75.7% to 97%. Most authors reported site-specific sensitivities and specificities, which varied greatly between locations. Site-specific sensitivities ranged from 10% to 88.9% (uterosacral ligaments), 20% to 100% (bladder), 33.3% to 98.1% (rectosigmoid colon), and 31% to 98.7% (pouch of Douglas). Site-specific specificities ranged from 75% to 99.6% (uterosacral ligaments), 96.4% to 100% (bladder), 86% to 100% (rectosigmoid colon), and 90% to 100% (pouch of Douglas). Transvaginal ultrasound is an accurate tool in the diagnosis of DIE; however, limited data exist as to whether this technique is accurate when performed by sonographers. More evidence surrounding the reliability between operators is also needed.


Assuntos
Endometriose , Endometriose/diagnóstico por imagem , Endometriose/cirurgia , Feminino , Humanos , Reto/diagnóstico por imagem , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ultrassonografia
12.
Int J Mol Sci ; 21(12)2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32580352

RESUMO

Gold nanoparticle (GNP) enhanced proton therapy is a promising treatment concept offering increased therapeutic effect. It has been demonstrated in experiments which provided indications that reactive species play a major role. Simulations of the radiolysis yield from GNPs within a cell model were performed using the Geant4 toolkit. The effect of GNP cluster size, distribution and number, cell and nuclear membrane absorption and intercellular yields were evaluated. It was found that clusters distributed near the nucleus increased the nucleus yield by 91% while reducing the cytoplasm yield by 7% relative to a disperse distribution. Smaller cluster sizes increased the yield, 200 nm clusters had nucleus and cytoplasm yields 117% and 35% greater than 500 nm clusters. Nuclear membrane absorption reduced the cytoplasm and nucleus yields by 8% and 35% respectively to a permeable membrane. Intercellular enhancement was negligible. Smaller GNP clusters delivered near sub-cellular targets maximise radiosensitisation. Nuclear membrane absorption reduces the nucleus yield, but can damage the membrane providing another potential pathway for biological effect. The minimal effect on adjacent cells demonstrates that GNPs provide a targeted enhancement for proton therapy, only effecting cells with GNPs internalised. The provided quantitative data will aid further experiments and clinical trials.


Assuntos
Células/efeitos da radiação , Ouro/química , Nanopartículas Metálicas/química , Modelos Biológicos , Terapia com Prótons , Radiólise de Impulso , Radiossensibilizantes/química , Método de Monte Carlo
13.
Sci Eng Ethics ; 26(1): 275-292, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30806940

RESUMO

The aim of this article is to offer a view of the current status of women in medical physics and biomedical engineering, while focusing on solutions towards gender balance and providing examples of current activities carried out at national and international levels. The International Union of Physical and Engineering Scientists in Medicine is committed to advancing women in science and health and has several initiatives overseen by the Women in Medical Physics and Biomedical Engineering Task Group. Some of the main strategies proposed by the Task Group to attain gender balance are: (a) identify and promote female role models that achieve successful work-life balance, (b) establish programs to develop female leaders, (c) create opportunities for females to increase the international visibility within the scientific community, and (d) establish archives and databases of women in STEM.


Assuntos
Engenharia Biomédica/organização & administração , Equidade de Gênero , Liderança , Tutoria , Física/organização & administração , Mulheres , Comitês Consultivos , Feminino , Humanos , Internacionalidade , Relatório de Pesquisa
14.
Int J Mol Sci ; 20(17)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31480532

RESUMO

Gold nanoparticles (GNPs) are promising radiosensitizers with the potential to enhance radiotherapy. Experiments have shown GNP enhancement of proton therapy and indicated that chemical damage by reactive species plays a major role. Simulations of the distribution and yield of reactive species from 10 ps to 1 µs produced by a single GNP, two GNPs in proximity and a GNP cluster irradiated with a proton beam were performed using the Geant4 Monte Carlo toolkit. It was found that the reactive species distribution at 1 µs extended a few hundred nm from a GNP and that the largest enhancement occurred over 50 nm from the nanoparticle. Additionally, the yield for two GNPs in proximity and a GNP cluster was reduced by up to 17% and 60% respectively from increased absorption. The extended range of action from the diffusion of the reactive species may enable simulations to model GNP enhanced proton therapy. The high levels of absorption for a large GNP cluster suggest that smaller clusters and diffuse GNP distributions maximize the total radiolysis yield within a cell. However, this must be balanced against the high local yields near a cluster particularly if the cluster is located adjacent to a biological target.


Assuntos
Ouro , Nanopartículas Metálicas/uso terapêutico , Modelos Biológicos , Terapia com Prótons , Animais , Humanos , Nanopartículas Metálicas/química , Método de Monte Carlo , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Radiossensibilizantes/uso terapêutico
15.
Int J Mol Sci ; 19(9)2018 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-30149561

RESUMO

It is an agreed fact that overall survival among head and neck cancer patients has increased over the last decade. Several factors however, are still held responsible for treatment failure requiring more in-depth evaluation. Among these, hypoxia and proliferation-specific parameters are the main culprits, along with the more recently researched cancer stem cells. This paper aims to present the latest developments in the field of biomarkers for hypoxia, stemness and tumour proliferation, from an imaging perspective that includes both Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) as well as functional magnetic resonance imaging (MRI). Quantitative imaging of biomarkers is a prerequisite for accurate treatment response assessment, bringing us closer to the highly needed personalised therapy.


Assuntos
Biomarcadores , Diagnóstico por Imagem , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/metabolismo , Proliferação de Células , Diagnóstico por Imagem/métodos , Neoplasias de Cabeça e Pescoço/etiologia , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Hipóxia/diagnóstico por imagem , Hipóxia/etiologia , Hipóxia/metabolismo , Imageamento por Ressonância Magnética/métodos , Imagem Molecular , Células-Tronco Neoplásicas/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos
16.
Acta Oncol ; 56(7): 899-908, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28375694

RESUMO

BACKGROUND: The worldwide incidence of esophageal cancer has greatly increased over the past few decades making it the sixth deadliest cancer. The disease is often detected in advanced stages when surgery is no longer an option. The standard treatment in these situations is combined chemoradiotherapy, by employing drug cocktails that lead to optimal treatment outcomes both from the perspective of tumor control and normal tissue toxicity. METHODS: The aim of this work was to collate the existing trials and clinical studies reported on non-operable esophageal cancer and to analyze the results based on treatment outcomes after various drug combinations. RESULTS: Of all drug combinations, cisplatin/5-FU is the most well established chemotherapy regimen for esophageal cancer as both neoadjuvant therapy, an alternative option to surgery, and for palliative purposes. Although this regimen is associated with the most toxicity, it also appears to have the best survival benefit and relief of symptoms. CONCLUSIONS: More research is warranted to further increase the therapeutic ratio in non-operable esophageal cancers.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Esofágicas/tratamento farmacológico , Terapia Neoadjuvante , Humanos , Prognóstico
18.
Acta Oncol ; 55(11): 1331-1337, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27379458

RESUMO

AIMS: There is evidence towards the induction of second primary cancers (SPCs) after breast radiotherapy (RT). Organs, such as the lungs and the esophagus, have been identified as common sites for SPC formation. As a result, the current study investigated the risk of secondary carcinogenesis associated with particular RT techniques for breast cancer; including whole breast, segmented breast, partial breast and mammosite brachytherapy. METHODS: In this study, seven breast cancer patients had all major organs contoured on their planning computed tomography (CT) images. Whole breast, segmented breast, accelerated partial breast irradiation (APBI) and mammosite boost treatment plans were generated for each patient using Pinnacle3 treatment planning system. Differential dose-volume histograms were generated for a number of critical structures: bladder, brain and central nervous system (CNS), breast, colon, liver, lung, mouth and pharynx, esophagus, ovary, salivary gland, small intestine, stomach, and uterus. The lifetime attributed risk (LAR) of cancer induction was estimated using the Schneider et al. excess absolute risk models and dose-volume histograms for the above organs. RESULTS: The sites with the highest LAR estimates were the ipsilateral and contralateral lungs, and contralateral breast for all treatment techniques. For all sites, the LAR estimates for the segmented breast and mammosite treatments were lower than those for the whole breast and APBI treatments. For right-sided target volumes the liver also resulted in high LAR estimates, with all techniques having a LAR greater than 20 per 10 000 person-years (PY), except for mammosite with a mean LAR estimate of 13.2 per 10 000 PY. For left-sided target volumes the stomach also resulted in high LAR estimates, with both whole breast and APBI having a LAR greater than 20 per 10 000 PY, and mammosite the lowest with a LAR of 8.3 per 10 000 PY. CONCLUSION: It is concluded that the lungs and contralateral breast showed high LAR estimates.


Assuntos
Braquiterapia/efeitos adversos , Neoplasias da Mama/radioterapia , Segunda Neoplasia Primária/etiologia , Idoso , Braquiterapia/métodos , Esôfago/efeitos da radiação , Feminino , Humanos , Fígado/efeitos da radiação , Pulmão/efeitos da radiação , Neoplasias Pulmonares/etiologia , Pessoa de Meia-Idade , Órgãos em Risco/efeitos da radiação , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Fatores de Risco , Estômago/efeitos da radiação
19.
Anal Chem ; 87(21): 10693-7, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26461268

RESUMO

Internalized gold nanoparticles were quantified in large numbers of individual prostate cancer cells using large area synchrotron X-ray fluorescence microscopy. Cells were also irradiated with a 6 MV linear accelerator to assess the biological consequence of radiosensitization with gold nanoparticles. A large degree of heterogeneity in nanoparticle uptake between cells resulted in influenced biological effect.


Assuntos
Células/efeitos da radiação , Fluorescência , Luz , Nanopartículas Metálicas/química , Células/efeitos dos fármacos , Ouro/química , Humanos , Masculino , Neoplasias da Próstata/tratamento farmacológico , Raios X
20.
Cell Biol Toxicol ; 30(1): 55-66, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24459009

RESUMO

The radioprotective agent amifostine is a free radical scavenger that can protect cells from the damaging effects of ionising radiation when administered prior to radiation exposure. However, amifostine has also been shown to protect cells from chromosomal mutations when administered after radiation exposure. As apoptosis is a common mechanism by which cells with mutations are removed from the cell population, we investigated whether amifostine stimulates apoptosis when administered after radiation exposure. We chose to study a relatively low dose which is the maximum radiation dose for radiation emergency workers (0.25 Gy) and a high dose relevant to radiotherapy exposures (6 Gy). Mice were administered 400 mg/kg amifostine 30 min before, or 3 h after, whole-body irradiation with 0.25 or 6 Gy X-rays and apoptosis was analysed 3 or 7 h later in spleen and bone marrow. We observed a significant increase in radiation-induced apoptosis in the spleen of mice when amifostine was administered before or after 0.25 Gy X-rays. In contrast, when a high dose of radiation was used (6 Gy), amifostine caused a reduction in radiation-induced apoptosis 3 h post-irradiation in spleen and bone marrow similar to previously published studies. This is the first study to investigate the effect of amifostine on radiation-induced apoptosis at a relatively low radiation dose and the first to demonstrate that while amifostine can reduce apoptosis from high doses of radiation, it does not mediate the same effect in response to low-dose exposures. These results suggest that there may be a dose threshold at which amifostine protects from radiation-induced apoptosis and highlight the importance of examining a range of radiation doses and timepoints.


Assuntos
Amifostina/farmacologia , Apoptose/efeitos dos fármacos , Lesões Experimentais por Radiação/prevenção & controle , Protetores contra Radiação/farmacologia , Amifostina/administração & dosagem , Animais , Apoptose/efeitos da radiação , Medula Óssea/efeitos dos fármacos , Medula Óssea/patologia , Medula Óssea/efeitos da radiação , Relação Dose-Resposta à Radiação , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Lesões Experimentais por Radiação/patologia , Protetores contra Radiação/administração & dosagem , Baço/efeitos dos fármacos , Baço/patologia , Baço/efeitos da radiação
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