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1.
Nat Commun ; 11(1): 4655, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938918

RESUMO

Purely organic room-temperature phosphorescence has attracted attention for bioimaging but can be quenched in aqueous systems. Here we report a water-soluble ultralong organic room-temperature phosphorescent supramolecular polymer by combining cucurbit[n]uril (CB[7], CB[8]) and hyaluronic acid (HA) as a tumor-targeting ligand conjugated to a 4-(4-bromophenyl)pyridin-1-ium bromide (BrBP) phosphor. The result shows that CB[7] mediated pseudorotaxane polymer CB[7]/HA-BrBP changes from small spherical aggregates to a linear array, whereas complexation with CB[8] results in biaxial pseudorotaxane polymer CB[8]/HA-BrBP which transforms to relatively large aggregates. Owing to the more stable 1:2 inclusion complex between CB[8] and BrBP and the multiple hydrogen bonds, this supramolecular polymer has ultralong purely organic RTP lifetime in water up to 4.33 ms with a quantum yield of 7.58%. Benefiting from the targeting property of HA, this supramolecular polymer is successfully applied for cancer cell targeted phosphorescence imaging of mitochondria.


Assuntos
Mitocôndrias/efeitos dos fármacos , Polímeros/química , Células A549 , Células HEK293 , Humanos , Ácido Hialurônico/química , Ligação de Hidrogênio , Medições Luminescentes , Microscopia Confocal , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Polímeros/metabolismo , Taxoides/química , Temperatura
2.
Lancet Oncol ; 21(8): 1077-1088, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32758462

RESUMO

BACKGROUND: Accurate survival estimates are important for cancer control planning. Although observed survival estimates are unavailable for many countries, where they are available, wide variations are reported. Understanding the impact of specific treatment and imaging modalities can help decision makers to effectively allocate resources to improve cancer survival in their local context. METHODS: We developed a microsimulation model of stage-specific cancer survival in 200 countries and territories for 11 cancers (oesophagus, stomach, colon, rectum, anus, liver, pancreas, lung, breast, cervix uteri, and prostate) comprising 60% of global diagnosed cancer cases. The model accounts for country-specific availability of treatment (chemotherapy, surgery, radiotherapy, and targeted therapy) and imaging modalities (ultrasound, x-ray, CT, MRI, PET, single-photon emission CT), as well as quality of care. We calibrated the model to reported survival estimates from CONCORD-3 (which reports global trends in cancer survival in 2000-14). We estimated 5-year net survival for diagnosed cancers in each country or territory and estimated potential survival gains from increasing the availability of individual treatment and imaging modalities, and more comprehensive packages of scale-up of these interventions. We report the mean and 95% uncertainty intervals (UIs) for all outcomes, calculated as the 2·5 and 97·5 percentiles of the simulation results. FINDINGS: The estimated global 5-year net survival for all 11 cancers combined is 42·6% (95% uncertainty interval 40·3-44·3), with survival in high-income countries being an average of 12 times (range 4-17) higher than that in low-income countries. Expanding availability of surgery or radiotherapy or improving quality of care would yield the largest survival gains in low-income (2·5-3·4 percentage point increase in survival) and lower-middle-income countries (2·4-6·1 percentage point increase), whereas upper-middle-income and high-income countries are more likely to benefit from improved availability of targeted therapy (0·7 percentage point increase for upper-middle income and 0·4 percentage point increase for high income). Investing in medical imaging will also be necessary to achieve substantial survival gains, with traditional modalities estimated to provide the largest gains in low-income settings, while MRI and PET would yield the largest gains in higher-income countries. Simultaneous expansion of treatment, imaging, and quality of care could improve 5-year net survival by more than ten times in low-income countries (3·8% [95% UI 0·5-9·2] to 45·2% [40·2-52·1]) and could more than double 5-year net survival in lower-middle-income countries (20·1% [7·2-31·7] to 47·1% [42·8-50·8]). INTERPRETATION: Scaling up both treatment and imaging availability could yield synergistic survival gains for patients with cancer. Expanding traditional modalities in lower-income settings might be a feasible pathway to improve survival before scaling up more modern technologies. FUNDING: Harvard T H Chan School of Public Health.


Assuntos
Saúde Global/estatística & dados numéricos , Neoplasias/diagnóstico por imagem , Neoplasias/mortalidade , Neoplasias/terapia , Análise de Sobrevida , Países Desenvolvidos/estatística & dados numéricos , Países em Desenvolvimento/estatística & dados numéricos , Humanos , Modelos Estatísticos
3.
Hell J Nucl Med ; 23 Suppl: 21-25, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32860392

RESUMO

On December 29, 2019, a hospital in the City of Wuhan, Hubei Province, in Central China, admitted four individuals with pneumonia. The hospital reported this occurrence to the local center for disease control (CDC), which lead Wuhan CDC staff to initiate a field investigation with a retrospective search for pneumonia patients. On December 31, 2019, the World Health Organization (WHO) was alerted by the Chinese authorities for several cases of pneumonia of unknown origin in the City of Wuhan. On January 7, 2020, a novel virus was identified as the causative agent, belonging to the Coronaviridae family (Severe Acute Respiratory Syndrome Coronavirus 2, SARS-CoV-2). Within the same month, the virus spread to other provinces of China, as well as a number of neighbouring countries. On February 11, 2020, the WHO announced that the SARS-CoV-2 - caused infection would be called coronavirus disease 2019 (COVID-19). On February 15, 2020, the first death due to COVID-19 in Europe was reported; a Chinese tourist who died in France. The first COVID-19 case was diagnosed in Greece on February 26th. The WHO declared COVID-19 a pandemic on 11 March 2020. On March 12th, movie theaters, gyms and courtrooms were closed in Greece and on March 13th, with 190 confirmed cases and 1 death, malls, cafés, restaurants, bars, beauty parlors, museums and archaeological sites were also closed. So far, COVID-19 pandemic has affected the way people live and work globally, and has resulted in extreme strain on the healthcare systems worldwide. Most of the nuclear medicine studies are performed on an out-patient basis. Therefore, without effective implementation of the required preventive measures, there is a significant risk for viral transmission when visiting nuclear medicine departments, particularly in periods of high community spread.


Assuntos
Infecções por Coronavirus/transmissão , Controle de Infecções/métodos , Serviço Hospitalar de Medicina Nuclear/normas , Pneumonia Viral/transmissão , Guias de Prática Clínica como Assunto , Cintilografia/normas , Infecções por Coronavirus/epidemiologia , Prioridades em Saúde , Humanos , Controle de Infecções/normas , Pneumopatias/diagnóstico por imagem , Neoplasias/diagnóstico por imagem , Serviço Hospitalar de Medicina Nuclear/organização & administração , Pandemias , Pneumonia Viral/epidemiologia , Cintilografia/métodos
4.
Clin Radiol ; 75(10): 794.e19-794.e26, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32732094

RESUMO

AIM: To evaluate the response measures in continuing an image-guided intervention service in two tertiary-level musculoskeletal oncology centres during the COVID-19 pandemic. MATERIALS AND METHODS: This study was a retrospective review of all patients undergoing image-guided intervention in the computed tomography (CT) and normal ultrasound (US) rooms from 24 March 2020 to 24 May 2020 (during the COVID-19 pandemic peak) at Royal National Orthopaedic Hospital, London, and Royal Orthopaedic Hospital, Birmingham, UK. Measures were put in place to address air pressures, airflow direction, aerosol generation, and the safe utilisation of existing scanning rooms and work lists for interventional procedures. RESULTS: Three hundred and thirty-one patients (164 at Royal National Orthopaedic Hospital and 167 at Royal Orthopaedic Hospital) underwent image-guided procedures at both sites in the CT and US rooms. At the Royal National Orthopaedic Hospital, 40% of all procedures were performed under general anaesthesia. These consisted of 47 CT biopsies, 7 CT radiofrequency ablations (RFAs), and 12 US biopsies. At the Royal Orthopaedic Hospital, 86% of all procedures were performed under local anaesthetic, with no general anaesthetic procedures. These consisted of 61 CT biopsies and 83 US biopsies. All 256 patients having procedures in the CT room had no post-procedural complications or COVID-19-related symptoms and morbidity on follow-up. CONCLUSION: By adopting a pragmatic approach with meticulous planning, a limited, but fully functional image-guided interventional list can be run without any adverse patient outcomes.


Assuntos
Infecções por Coronavirus/prevenção & controle , Sistema Musculoesquelético/diagnóstico por imagem , Neoplasias/patologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Radiografia Intervencionista/estatística & dados numéricos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Ultrassonografia de Intervenção/estatística & dados numéricos , Biópsia , Protocolos Clínicos , Arquitetura Hospitalar , Humanos , Sistema Musculoesquelético/patologia , Neoplasias/diagnóstico por imagem , Equipamento de Proteção Individual , Estudos Retrospectivos , Reino Unido
5.
Life Sci ; 258: 118206, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32758623

RESUMO

Scientists are looking for new therapies to cope with the rise in cancer worldwide. Since cancer cells overexpress peptide receptors and owing to small size, easy uptake by tumor cells, easy preparation, and with no toxicity, the use of radiolabeled peptides with high specificity and affinity for accurate imaging and therapy has attracted much attention. To develop an ideal imaging or treatment radiolabeled peptide, there are some aspects in the components of radiolabeled peptide including radionuclide, peptide, chelator, and spacer that should be considered. Some peptides, including somatostatin, RGD, neurotensin, bombesin, exendin, vasoactive intestinal peptide, and gastrin are currently under (pre)clinical investigations. Today, nanoparticles are suitable tools for targeting peptide for molecular imaging and therapy of tumors with low toxicity. This paper presents some essential aspects in developing a valuable radiolabeled peptide and some radiolabeled peptides with regard to their applications in tumor imaging and therapy in pre-clinical and clinical phases.


Assuntos
Diagnóstico por Imagem/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/metabolismo , Fragmentos de Peptídeos/metabolismo , Compostos Radiofarmacêuticos/metabolismo , Animais , Diagnóstico por Imagem/tendências , Humanos , Mediadores da Inflamação/metabolismo
6.
PLoS One ; 15(8): e0237606, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797089

RESUMO

BACKGROUND: There are many types of hand tumors, and it is often difficult for imaging diagnosticians to make a correct diagnosis, which can easily lead to misdiagnosis and delay in treatment. Thus in this paper, we propose a deep neural network for diagnose on MR Images of tumors of the hand in order to better define preoperative diagnosis and standardize surgical treatment. METHODS: We collected MRI figures of 221 patients with hand tumors from one medical center from 2016 to 2019, invited medical experts to annotate the images to form the annotation data set. Then the original image is preprocessed to get the image data set. The data set is randomly divided into ten parts, nine for training and one for test. Next, the data set is input into the neural network system for testing. Finally, average the results of ten experiments as an estimate of the accuracy of the algorithm. RESULTS: This research uses 221 images as dataset and the system shows an average confidence level of 71.6% in segmentation of hand tumors. The segmented tumor regions are validated through ground truth analysis and manual analysis by a radiologist. CONCLUSIONS: With the recent advances in convolutional neural networks, vast improvements have been made for image segmentation, mainly based on the skip-connection-linked encoder decoder deep architectures. Therefore, in this paper, we propose an automatic segmentation method based on DeepLab v3+ and achieved a good diagnostic accuracy rate.


Assuntos
Mãos/patologia , Processamento de Imagem Assistida por Computador/métodos , Neoplasias/diagnóstico por imagem , Mãos/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética , Neoplasias/patologia , Redes Neurais de Computação , Sensibilidade e Especificidade , Software
7.
Cancer Radiother ; 24(6-7): 658-666, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32859465

RESUMO

Radiation therapy (RT) is one of the main modalities of cancer treatment worldwide with computed tomography (CT), as the most commonly used imaging method for treatment planning system (TPS). Image reconstruction errors may greatly affect all the radiation therapy planning process, such as target delineation, dose calculation and delivery, particularly with particle therapy. Metallic implants, such as hip and spinal implants, and dental filling significantly deteriorate image quality. These hardware structures are often very complex in geometry leading to geometric complex artefacts in the clinical target volume (CTV) area, rendering the delineation of CTV challenging. In our review, we focus on the methods to overcome artefact consequences on CTV delineation: 1- medical approaches anticipating issues associated with imaging artefacts during preoperative multidisciplinary discussions while following standard recommendations; 2- common metal artefact reduction (MAR) methods such as manually override artefact regions, ballistics avoiding beam paths through implanted materials, megavoltage-CT (MVCT); 3- prospects with radiolucent implants, MAR algorithms and various methods of dual energy computed tomography (DECT). Despite substantial and broad evidence for their benefits, there is still no universal solution for cases involving implanted metallic devices. There is still a high need for research efforts to adapt technologies to our issue: "how do I accurately delineate the ideal CTV in a metal artefact area?"


Assuntos
Artefatos , Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Próteses e Implantes , Tomografia Computadorizada por Raios X , Carga Tumoral/efeitos da radiação , Humanos , Neoplasias/patologia , Radioterapia/métodos , Dosagem Radioterapêutica
8.
PLoS One ; 15(8): e0238106, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32845905

RESUMO

PURPOSE: Real-time monitoring of physiological changes of tumor tissue during radiation therapy (RT) could improve therapeutic efficacy and predict therapeutic outcomes. Cherenkov radiation is a normal byproduct of radiation deposited in tissue. Previous studies in rat tumors have confirmed a correlation between Cherenkov emission spectra and optical measurements of blood-oxygen saturation based on the tissue absorption coefficients. The purpose of this study is to determine if it is feasible to image Cherenkov emissions during radiation therapy in larger human-sized tumors of pet dogs with cancer. We also wished to validate the prior work in rats, to determine if Cherenkov emissions have the potential to act an indicator of blood-oxygen saturation or water-content changes in the tumor tissue-both of which have been correlated with patient prognosis. METHODS: A DoseOptics camera, built to image the low-intensity emission of Cherenkov radiation, was used to measure Cherenkov intensities in a cohort of cancer-bearing pet dogs during clinical irradiation. Tumor type and location varied, as did the radiation fractionation scheme and beam arrangement, each planned according to institutional standard-of-care. Unmodulated radiation was delivered using multiple 6 MV X-ray beams from a clinical linear accelerator. Each dog was treated with a minimum of 16 Gy total, in ≥3 fractions. Each fraction was split into at least three subfractions per gantry angle. During each subfraction, Cherenkov emissions were imaged. RESULTS: We documented significant intra-subfraction differences between the Cherenkov intensities for normal tissue, whole-tumor tissue, tissue at the edge of the tumor and tissue at the center of the tumor (p<0.05). Additionally, intra-subfraction changes suggest that Cherenkov emissions may have captured fluctuating absorption properties within the tumor. CONCLUSION: Here we demonstrate that it is possible to obtain Cherenkov emissions from canine cancers within a fraction of radiotherapy. The entire optical spectrum was obtained which includes the window for imaging changes in water and hemoglobin saturation. This lends credence to the goal of using this method during radiotherapy in human patients and client-owned pets.


Assuntos
Neoplasias/radioterapia , Raios X , Animais , Cães , Processamento de Imagem Assistida por Computador , Neoplasias/diagnóstico por imagem , Aceleradores de Partículas , Projetos Piloto , Estudos Prospectivos , Dosagem Radioterapêutica , Tomografia Computadorizada por Raios X
9.
Int J Nanomedicine ; 15: 4825-4845, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32753868

RESUMO

Background: Nanosized drug delivery systems (NDDSs) have shown excellent prospects in tumor therapy. However, insufficient penetration of NDDSs has significantly impeded their development due to physiological instability and low passive penetration efficiency. Methods: Herein, we prepared a core cross-linked pullulan-modified nanosized system, fabricated by visible-light-induced diselenide bond cross-linked method for transporting ß-Lapachone and doxorubicin prodrug (boronate-DOX, BDOX), to improve the physiological stability of the NDDSs for efficient passive accumulation in tumor blood vessels (ß-Lapachone/BDOX-CCS). Additionally, ultrasound (US) was utilized to transfer ß-Lapachone/BDOX-CCS around the tumor vessel in a relay style to penetrate the tumor interstitium. Subsequently, ß-Lapachone enhanced ROS levels by overexpressing NQO1, resulting in the transformation of BDOX into DOX. DOX, together with abundant levels of ROS, achieved synergistic tumor therapy. Results: In vivo experiments demonstrated that ultrasound (US) + cross-linked nanosized drug delivery systems (ß-Lapachone/BDOX-CCS) group showed ten times higher DOX accumulation in the tumor interstitium than the non-cross-linked (ß-Lapachone/BDOX-NCS) group. Conclusion: Thus, this strategy could be a promising method to achieve deep penetration of NDDSs into the tumor.


Assuntos
Doxorrubicina/uso terapêutico , Nanopartículas/química , Naftoquinonas/uso terapêutico , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Pró-Fármacos/uso terapêutico , Ultrassonografia , Animais , Ácidos Borônicos/química , Permeabilidade Capilar/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Reagentes para Ligações Cruzadas/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Endocitose/efeitos dos fármacos , Feminino , Glucanos/química , Células Hep G2 , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Naftoquinonas/farmacocinética , Tamanho da Partícula , Pró-Fármacos/farmacocinética , Espécies Reativas de Oxigênio/metabolismo , Distribuição Tecidual/efeitos dos fármacos
10.
Crit Rev Oncol Hematol ; 154: 103068, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32805498

RESUMO

In recent years the concept of precision medicine has become a popular topic particularly in medical oncology. Besides the identification of new molecular prognostic and predictive biomarkers and the development of new targeted and immunotherapeutic drugs, imaging has started to play a central role in this new era. Terms such as "radiomics", "radiogenomics" or "radi…-omics" are becoming increasingly common in the literature and soon they will represent an integral part of clinical practice. The use of artificial intelligence, imaging and "-omics" data can be used to develop models able to predict, for example, the features of the tumor immune microenvironment through imaging, and to monitor the therapeutic response beyond the standard radiological criteria. The aims of this narrative review are to provide a simplified guide for clinicians to these concepts, and to summarize the existing evidence on radiomics and "radi…-omics" in cancer immunotherapy.


Assuntos
Inteligência Artificial , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Humanos , Imunoterapia , Medicina de Precisão , Microambiente Tumoral
11.
Clin Imaging ; 67: 121-129, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32619773

RESUMO

As of April 17th, 2020, more than 2,190,010 COVID-19 cases with 147,010 deaths have been recorded worldwide. It has been suggested that a high mortality rate occurs in patients with severe disease and is associated with advanced age and underlying comorbidities, such as malignancies. To the best of our knowledge, no study has been conducted to evaluate chest CT features in patients with malignancy and concomitant COVID-19 infection. In fact, the imaging findings can be challenging and have not yet been fully understood in this setting. In this manuscript, we go over imaging findings in chest CT of patients with COVID-19 and known cancer. With the ongoing COVID-19 pandemic and exponentially increasing incidence throughout the world, in at-risk and vulnerable populations such as patients with known malignancies, infection with SARS-CoV-2 should be included in the differential considerations even with atypical image pictures. Detection of superimposed infection in patients with cancers who present with pulmonary infiltrations warrant correlation with clinical picture, contact history, and RT-PCR confirmatory testing.


Assuntos
Infecções por Coronavirus/epidemiologia , Pulmão/patologia , Neoplasias/epidemiologia , Pneumonia Viral/epidemiologia , Adulto , Betacoronavirus , Comorbidade , Infecções por Coronavirus/diagnóstico por imagem , Infecções por Coronavirus/virologia , Feminino , Humanos , Estudos Longitudinais , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Neoplasias/diagnóstico por imagem , Pandemias , Pneumonia Viral/diagnóstico por imagem , Pneumonia Viral/virologia , Tórax/diagnóstico por imagem , Tórax/patologia , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem
12.
Radiol Oncol ; 54(3): 329-334, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32726291

RESUMO

Background The COVID-19 pandemic has disrupted the provision and use of healthcare services throughout the world. In Slovenia, an epidemic was officially declared between mid-March and mid-May 2020. Although all non-essential health care services were put on hold by government decree, oncological services were listed as an exception. Nevertheless, as cancer control depends also on other health services and additionally major changes in people's behaviour likely occurred, we aimed to analyse whether cancer diagnosis and management were affected during the COVID-19 epidemic in Slovenia. Methods We analysed routine data for the period November 2019 through May 2020 from three sources: (1) from the Slovenian Cancer Registry we analysed data on pathohistological and clinical practice cancer notifications from two major cancer centres in Ljubljana and Maribor; (2) from the e-referral system we analysed data on all referrals in Slovenia issued for oncological services, stratified by type of referral; and (3) from the administrative data of the Institute of Oncology Ljubljana we analysed data on outpatient visits by type as well as on diagnostic imaging performed. Results Compared to the November 2019 - February 2020 average, the decrease in April 2020 was about 43% and 29% for pathohistological and clinical cancer notifications; 33%, 46% and 85% for first, control and genetic counselling referrals; 19% (53%), 43% (72%) and 20% (21%) for first (and control) outpatient visits at the radiotherapy, surgery and medical oncology sectors at the Institute of Oncology Ljubljana, and 48%, 76%, and 42% for X-rays, mammograms and ultrasounds performed at the Institute, respectively. The number of CT and MRI scans performed was not affected. Conclusions Significant drops in first referrals for oncological services, first visits and imaging studies performed at the Institute, as well as cancer notifications in April 2020 point to a possibility of a delayed cancer diagnosis for some patients during the first surge of SARS-CoV-2 cases in Slovenia. The reasons for the delay cannot be ascertained with certainty and could be linked to health-seeking behaviour of the patients, the beliefs and practices of doctors and/ or the health system management during the epidemic. Drops in control referrals and control visits were expected and are most likely due to the Institute of Oncology Ljubljana postponing non-essential follow-ups through May 2020.


Assuntos
Infecções por Coronavirus/epidemiologia , Neoplasias/diagnóstico , Neoplasias/terapia , Pandemias , Pneumonia Viral/epidemiologia , Assistência Ambulatorial/estatística & dados numéricos , Betacoronavirus , Institutos de Câncer/estatística & dados numéricos , Diagnóstico Tardio , Diagnóstico por Imagem/estatística & dados numéricos , Utilização de Instalações e Serviços , Acesso aos Serviços de Saúde , Humanos , Neoplasias/diagnóstico por imagem , Encaminhamento e Consulta/estatística & dados numéricos , Sistema de Registros , Eslovênia/epidemiologia
14.
Cancer Radiother ; 24(5): 444-452, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32620457

RESUMO

The aim of the present paper is to systematically review all available literature on preradiotherapy high uptake areas (hotspots) as a potential target for dose escalation in different tumour sites, and to understand the potential role and limitations of fluorodeoxyglucose (FDG)-positron-emission tomography (PET)/computed tomography (CT) in this context. An electronic database (Medline) search was conducted to identify articles reporting on a correlation between high tracer uptake on pretreatment PET and preferential sites of local recurrence after radiotherapy. Search was limited to English language. No date range limitation was applied. Among 45 studies initially identified, nine series matching with inclusion criteria have finally been retained from the literature after reviewing (5 retrospective and 4 prospective). Primary tumour locations were head-neck (n=2), lung (n=4), oesophageal (n=2) and rectal (n=1) areas. Overlaps between FDG hotspot on preradiotherapy PET/CT and site of local recurrence on post-treatment scan showed good to excellent agreement. Only studies on head-neck cancer reported moderate agreement probably explained by the lack of reproducibility of the patients positioning between pre- and post-treatment FDG-PET/CT; and by the rigid registration process of images limited by post-therapeutic changes that highly affect anatomical landmarks. FDG hotspot-guided radiotherapy may allow dose escalation in respecting a robust methodology (treatment position, co-registration method, four-dimensional PET).


Assuntos
Fluordesoxiglucose F18 , Recidiva Local de Neoplasia/diagnóstico por imagem , Neoplasias/diagnóstico por imagem , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Pontos de Referência Anatômicos/diagnóstico por imagem , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/radioterapia , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Neoplasias/radioterapia , Posicionamento do Paciente , Estudos Prospectivos , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/radioterapia , Estudos Retrospectivos
15.
Nat Commun ; 11(1): 3637, 2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32686685

RESUMO

We report a strategy to boost Fenton reaction triggered by an exogenous circularly polarized magnetic field (MF) to enhance ferroptosis-like cell-death mediated immune response, as well as endow a responsive MRI capability by using a hybrid core-shell vesicles (HCSVs). HCSVs are prepared by loading ascorbic acid (AA) in the core and poly(lactic-co-glycolic acid) shell incorporating iron oxide nanocubes (IONCs). MF triggers the release of AA, resulting in the increase of ferrous ions through the redox reaction between AA and IONCs. A significant tumor suppression is achieved by Fenton reaction-mediated ferroptosis-like cell-death. The oxidative stress induced by the Fenton reaction leads to the exposure of calreticulin on tumor cells, which leads to dendritic cells maturation and the infiltration of cytotoxic T lymphocytes in tumor. Furthermore, the depletion of ferric ions during treatment enables monitoring of the Fe reaction in MRI-R2* signal change. This strategy provides a perspective on ferroptosis-based immunotherapy.


Assuntos
Ferroptose/efeitos dos fármacos , Campos Magnéticos , Nanopartículas de Magnetita , Neoplasias/terapia , Animais , Ácido Ascórbico/farmacologia , Calreticulina/metabolismo , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Compostos Férricos/química , Imunoterapia/métodos , Imagem por Ressonância Magnética , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/uso terapêutico , Camundongos , Nanomedicina/métodos , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias/diagnóstico por imagem , Neoplasias/imunologia , Estresse Oxidativo , Linfócitos T Citotóxicos/metabolismo
17.
Recent Results Cancer Res ; 216: 31-110, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32594384

RESUMO

Imaging in Oncology is rapidly moving from the detection and size measurement of a lesion to the quantitative assessment of metabolic processes and cellular and molecular interactions. Increasing insights into cancer as a complex disease with involvement of the tumor stroma in tumor pathobiological processes have made it clear that for successful control of cancer, treatment strategies should not only be directed at the cancer cells but should also take aspects of the tumor microenvironment into account. This requires an understanding of the complex molecular and cellular interactions in cancer tissue. Recent developments in imaging technology have increased the possibility to image various pathobiological processes in cancer development and response to treatment. For computed tomography (CT) and magnetic resonance imaging (MRI) various improvements in hardware, software, and imaging probes have lifted these modalities from classical anatomical imaging techniques to techniques suitable to image and quantify various physiological processes and molecular and cellular interactions. Next to a more general overview of possible imaging targets in oncology, this chapter provides an overview of the various developments in CT and MRI technology and some specific applications.


Assuntos
Imagem por Ressonância Magnética , Neoplasias/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Humanos , Oncologia
18.
Recent Results Cancer Res ; 216: 135-154, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32594386

RESUMO

Ultrasound imaging plays an important role in oncological imaging for more than five decades now. It can be applied in all tissues that are not occluded by bone or gas-filled regions. The quality of ultrasound images benefitted strongly from improved electronics and increased computational power. To the morphological imaging, several functional imaging methods were added: Flow visualization became possible by Doppler techniques and as a recent addition the elastic properties of tissues can be imaged by elastographic methods with transient shear wave imaging. In the beginning of molecular imaging, ultrasound with its contrast based on mechanical tissue properties was an unlikely candidate to play a role. However, with contrast agents consisting of micrometer-sized gas bubbles, which can be imaged with high sensitivity, ligands addressing targets in the vascular wall could be used. Because even single bubbles can be detected, this led to various ultrasound molecular imaging techniques and the ongoing development of clinical molecular contrast media. In this chapter, the basic properties of ultrasonic imaging like its contrast mechanisms and spatiotemporal resolution are discussed. The image formation and its ongoing change from line-oriented scanning to full-volume reconstructions are explained. Then, the ultrasound contrast media and imaging techniques are introduced and emerging new methods like super-resolution vascular imaging demonstrate the ongoing development in this field.


Assuntos
Neoplasias/diagnóstico por imagem , Ultrassonografia , Meios de Contraste , Humanos , Microbolhas , Imagem Molecular
19.
Recent Results Cancer Res ; 216: 227-282, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32594389

RESUMO

Single photon emission computed tomography (SPECT) is the state-of-the-art imaging modality in nuclear medicine despite the fact that only a few new SPECT tracers have become available in the past 20 years. Critical for the future success of SPECT is the design of new and specific tracers for the detection, localization, and staging of a disease and for monitoring therapy. The utility of SPECT imaging to address oncologic questions is dependent on radiotracers that ideally exhibit excellent tissue penetration, high affinity to the tumor-associated target structure, specific uptake and retention in the malignant lesions, and rapid clearance from non-targeted tissues and organs. In general, a target-specific SPECT radiopharmaceutical can be divided into two main parts: a targeting biomolecule (e.g., peptide, antibody fragment) and a γ-radiation-emitting radionuclide (e.g., 99mTc, 123I). If radiometals are used as the radiation source, a bifunctional chelator is needed to link the radioisotope to the targeting entity. In a rational SPECT tracer design, these single components have to be critically evaluated in order to achieve a balance among the demands for adequate target binding, and a rapid clearance of the radiotracer. The focus of this chapter is to depict recent developments of tumor-targeted SPECT radiotracers for imaging of cancer diseases. Possibilities for optimization of tracer design and potential causes for design failure are discussed and highlighted with selected examples.


Assuntos
Neoplasias/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Humanos , Compostos Radiofarmacêuticos
20.
Recent Results Cancer Res ; 216: 189-226, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32594388

RESUMO

Magnetic resonance imaging is characterized by high spatial resolution and unsurpassed soft tissue discrimination. Development and characterization of both intrinsic and extrinsic magnetic resonance (MR) imaging probes in the last decade has further strengthened the pivotal role MR imaging holds in the assessment of cancer in preclinical and translational settings. Sophisticated chemical modifications of a variety of nanoparticulate probes hold the potential to deliver valuable multifunctional tools applicable in diagnostics and/or treatment in human oncology. MR imaging suffers from a lack of sensitivity achievable by, e.g., nuclear medicine imaging methods. Advantages of including additional functionality/functionalities in a probe suitable for MR imaging are thus numerous, comprising the addition of fundamentally different imaging information (diagnostics), drug delivery (therapy), or the combination of both (theranostics). In recent years, we have witnessed a plethora of preclinical multimodal or multifunctional imaging probes being published mainly as proof-of-principle studies, yet only a handful are readily applicable in clinical settings. This chapter summarizes recent innovations in the development of multifunctional MR imaging probes and discusses the suitability of these probes for clinical transfer.


Assuntos
Imagem por Ressonância Magnética/métodos , Neoplasias/diagnóstico por imagem , Humanos
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