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1.
Int J Mol Sci ; 22(6)2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33808935

RESUMO

Antioxidant agents are promising pharmaceuticals to prevent salivary gland (SG) epithelial injury from radiotherapy and their associated irreversible dry mouth symptoms. Epigallocatechin-3-gallate (EGCG) is a well-known antioxidant that can exert growth or inhibitory biological effects in normal or pathological tissues leading to disease prevention. The effects of EGCG in the various SG epithelial compartments are poorly understood during homeostasis and upon radiation (IR) injury. This study aims to: (1) determine whether EGCG can support epithelial proliferation during homeostasis; and (2) investigate what epithelial cells are protected by EGCG from IR injury. Ex vivo mouse SG were treated with EGCG from 7.5-30 µg/mL for up to 72 h. Next, SG epithelial branching morphogenesis was evaluated by bright-field microscopy, immunofluorescence, and gene expression arrays. To establish IR injury models, linear accelerator (LINAC) technologies were utilized, and radiation doses optimized. EGCG epithelial effects in these injury models were assessed using light, confocal and electron microscopy, the Griess assay, immunohistochemistry, and gene arrays. SG pretreated with EGCG 7.5 µg/mL promoted epithelial proliferation and the development of pro-acinar buds and ducts in regular homeostasis. Furthermore, EGCG increased the populations of epithelial progenitors in buds and ducts and pro-acinar cells, most probably due to its observed antioxidant activity after IR injury, which prevented epithelial apoptosis. Future studies will assess the potential for nanocarriers to increase the oral bioavailability of EGCG.


Assuntos
Células Acinares/efeitos dos fármacos , Células Acinares/efeitos da radiação , Catequina/análogos & derivados , Protetores contra Radiação/farmacologia , Glândulas Salivares/efeitos dos fármacos , Glândulas Salivares/efeitos da radiação , Animais , Apoptose/efeitos dos fármacos , Catequina/farmacologia , Linhagem Celular , Células Epiteliais/efeitos dos fármacos , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Humanos , Imuno-Histoquímica , Estresse Oxidativo , Lesões por Radiação/prevenção & controle
2.
Medicine (Baltimore) ; 100(16): e25540, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33879699

RESUMO

OBJECTIVES: The purpose of this study is to investigate the effect of the comprehensive oral care program on oral health status and symptoms in head and neck cancer (HNC) patients undergoing radiotherapy. METHODS: This was a quasi-experimental study using a non-equivalent control group in non-synchronized design. All participants including control and experimental group were asked for the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire H&N35 (EORTC QLQ-H&N35) and given an oral health education 4 times at baseline, immediate postradiotherapy, 3 months after radiotherapy, and 6 months after radiotherapy. In each visit except for final, the experimental group was given fluoride varnish application and fluoride mouth rinsing solution for daily use. Oral health examination for dental caries, plaque score (PS), bleeding on probing (BOP), and salivary flow rate was performed in baseline and 6 months after radiotherapy. Statistical analyses were done by paired t-tests and mixed ANCOVA repeated-measures analysis. RESULTS: From November 1, 2013 to October 31, 2015, a total 61 patients undergoing radiotherapy for HNC cancer were enrolled (30 in control and 31 in experimental groups). Decrease in salivary flow rate was comparable between 2 groups. Dental caries increased in control group (P = .006); PS and BOP were decreased in experimental group (P < .001 and .004, respectively). Experimental group showed lower swallowing, speech problems, and less sexuality scores in EORTC QLQ-H&N35 than control group. CONCLUSION: We found improvement in oral health and the quality of life in HNC patients with comprehensive oral care intervention by dental professionals. Communicating and cooperating between the healthcare and dental professionals is needed to raise the quality of health care services for HNC patients receiving radiotherapy.


Assuntos
Assistência Odontológica Integral/métodos , Neoplasias de Cabeça e Pescoço/terapia , Saúde Bucal , Qualidade de Vida , Lesões por Radiação/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Cárie Dentária/etiologia , Cárie Dentária/prevenção & controle , Feminino , Neoplasias de Cabeça e Pescoço/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças da Boca/etiologia , Doenças da Boca/prevenção & controle , Ensaios Clínicos Controlados não Aleatórios como Assunto , Projetos de Pesquisa
3.
Anticancer Res ; 41(4): 2101-2110, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33813420

RESUMO

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


Assuntos
Anti-Inflamatórios/administração & dosagem , Proctite/prevenção & controle , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/radioterapia , Radioterapia de Intensidade Modulada , Administração Tópica , Idoso , Idoso de 80 Anos ou mais , Beclometasona/administração & dosagem , Enema/métodos , Humanos , Ácido Hialurônico/administração & dosagem , Itália , Masculino , Pessoa de Meia-Idade , Tratamentos com Preservação do Órgão/métodos , Proctite/etiologia , Neoplasias da Próstata/patologia , Hipofracionamento da Dose de Radiação , Lesões por Radiação/prevenção & controle , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/efeitos adversos , Radioterapia Guiada por Imagem/métodos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos
4.
Saudi Med J ; 42(3): 247-254, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33632902

RESUMO

This review summarizes the beginning of radiotherapy, techniques of modern radiation therapy with different types, toxicities induced by radiotherapy and their management. Head and neck radiation therapy is still improving for the better management and control of the cancer and induced radiotherapy toxicities.


Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Radioterapia/métodos , Radioterapia/tendências , Fracionamento da Dose de Radiação , Exantema/etiologia , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Oxigenação Hiperbárica , Osteorradionecrose/etiologia , Lesões por Radiação/etiologia , Lesões por Radiação/prevenção & controle , Radioterapia/efeitos adversos , Espécies Reativas de Oxigênio/metabolismo
5.
Mil Med Res ; 8(1): 3, 2021 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-33455578

RESUMO

BACKGROUND: In radiological emergencies with radionuclide incorporation, decorporation treatment is particularly effective if started early. Treating all people potentially contaminated ("urgent treatment") may require large antidote stockpiles. An efficacious way to reduce antidote requirements is by using radioactivity screening equipment. We analyzed the suitability of such equipment for triage purposes and determined the most efficient mix of screening units and antidote daily doses. METHODS: The committed effective doses corresponding to activities within the detection limits of monitoring portals and mobile whole-body counters were used to assess their usefulness as triage tools. To determine the optimal resource mix, we departed from a large-scale scenario (60,000 victims) and based on purchase prices of antidotes and screening equipment in Germany, we calculated efficiencies of different combinations of medical countermeasure resources by data envelopment analysis. Cost-effectiveness was expressed as the costs per life year saved and compared to risk reduction opportunities in other sectors of society as well as the values of a statistical life. RESULTS: Monitoring portals are adequate instruments for a sensitive triage after cesium-137 exposure with a high screening throughput. For the detection of americium-241 whole-body counters with a lower daily screening capacity per unit are needed. Assuming that 1% of the potentially contaminated patients actually need decorporation treatment, an efficient resource mix includes 6 monitoring portals and 25 mobile whole-body counters. The optimum mix depends on price discounts and in particular the fraction of victims actually needing treatment. The cost-effectiveness of preparedness for a "dirty bomb" attack is less than for common health care, but costs for a life year saved are less than for many risk-reduction interventions in the environmental sector. CONCLUSION: To achieve economic efficiency a high daily screening capacity is of major importance to substantially decrease the required amount of antidote doses. Among the determinants of the number of equipment units needed, the fraction of the potentially contaminated victims that actually needs treatment is the most difficult to assess. Judging cost-effectiveness of the preparedness for "dirty bomb" attacks is an issue of principle that must be dealt with by political leaders.


Assuntos
Contramedidas Médicas , Armas Nucleares , Terrorismo/prevenção & controle , Humanos , Programas de Rastreamento/métodos , Lesões por Radiação/tratamento farmacológico , Lesões por Radiação/prevenção & controle , Protetores contra Radiação/uso terapêutico , Terrorismo/tendências
6.
Br J Radiol ; 94(1120): 20200931, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33481641

RESUMO

OBJECTIVES: The aim of this pilot study was to investigate in two rectal cancer patients undergoing neoadjuvant chemo-radiotherapy (nCRT) the implant feasibility and dosimetric benefit in sexual organ-sparing of an injectable, absorbable, radiopaque hydrogel spacer. METHODS: Two rectal cancer patients (one male and one female) underwent hydrogel implant between rectum and vagina/prostate before nCRT and curative surgery. A CT scan was performed before and after injection and a comparative dosimetric study was performed testing a standard (45/50 Gy) and a dose escalated (46/55.2 Gy) schedule. RESULTS: In both patients, the spacer implant in the recto-prostatic or recto-vaginal space was feasible and well tolerated. For the male, the dosimetric benefit with spacer was minimal for sexual organs. For the female however, doses delivered to the vagina were significantly reduced with spacer with a mean reduction of more than 5 Gy for both regimens. CONCLUSIONS: For organ preservation protocols and selected sexually active female patients, use of hydrogel spacers can be considered to spare sexual organs from the high radiotherapy dose levels. ADVANCES IN KNOWLEDGE: For females with advanced rectal tumor, a spacer implant between the rectum and the vagina before nCRT is feasible and reduces doses delivered to the vagina.


Assuntos
Hidrogéis/administração & dosagem , Órgãos em Risco/diagnóstico por imagem , Lesões por Radiação/prevenção & controle , Neoplasias Retais/radioterapia , Tomografia Computadorizada por Raios X/métodos , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Próstata/diagnóstico por imagem , Vagina/diagnóstico por imagem
8.
Phytomedicine ; 80: 153402, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33203590

RESUMO

BACKGROUND: Although great achievements have been made in the field of cancer therapy, chemotherapy and radiotherapy remain the mainstay cancer therapeutic modalities. However, they are associated with various side effects, including cardiocytotoxicity, nephrotoxicity, myelosuppression, neurotoxicity, hepatotoxicity, gastrointestinal toxicity, mucositis, and alopecia, which severely affect the quality of life of cancer patients. Plants harbor a great chemical diversity and flexible biological properties that are well-compatible with their use as adjuvant therapy in reducing the side effects of cancer therapy. PURPOSE: This review aimed to comprehensively summarize the molecular mechanisms by which phytochemicals ameliorate the side effects of cancer therapies and their potential clinical applications. METHODS: We obtained information from PubMed, Science Direct, Web of Science, and Google scholar, and introduced the molecular mechanisms by which chemotherapeutic drugs and irradiation induce toxic side effects. Accordingly, we summarized the underlying mechanisms of representative phytochemicals in reducing these side effects. RESULTS: Representative phytochemicals exhibit a great potential in reducing the side effects of chemotherapy and radiotherapy due to their broad range of biological activities, including antioxidation, antimutagenesis, anti-inflammation, myeloprotection, and immunomodulation. However, since a majority of the phytochemicals have only been subjected to preclinical studies, clinical trials are imperative to comprehensively evaluate their therapeutic values. CONCLUSION: This review highlights that phytochemicals have interesting properties in relieving the side effects of chemotherapy and radiotherapy. Future studies are required to explore the clinical benefits of these phytochemicals for exploitation in chemotherapy and radiotherapy.


Assuntos
Antineoplásicos/efeitos adversos , Compostos Fitoquímicos/farmacologia , Substâncias Protetoras/farmacologia , Radioterapia/efeitos adversos , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Antineoplásicos/uso terapêutico , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Estresse Oxidativo/efeitos dos fármacos , Lesões por Radiação/prevenção & controle
9.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 39(5): 303-315, sept.-oct. 2020. graf
Artigo em Espanhol | IBECS | ID: ibc-198292

RESUMO

El modelo lineal sin umbral (MLSU) es una función dosis-respuesta teórica obtenida de extrapolar los efectos tardíos debidos a la exposición a altas dosis de radiación ionizante al rango de las bajas dosis, pero existen grandes incertidumbres respecto a su validez. La aceptación del MLSU como modelo probabilístico preponderante ha sobrevivido hasta nuestros días y constituye la piedra angular que sostiene las políticas actuales de protección radiológica. En las últimas décadas, los avances en biología molecular y evolutiva, en la inmunología del cáncer, así como los resultados obtenidos de los estudios epidemiológicos y en modelos animales, han puesto en entredicho la fiabilidad del MLSU en favor de otras alternativas, como la teoría hormética. A la vista de las evidencias, se hace necesario un debate entre las sociedades científicas implicadas y los organismos reguladores que aborde una redefinición de las bases de la protección radiológica, cuya importancia sería capital en el ámbito médico


The linear non-threshold model (LNTM) is a theoretical dose-response function as a result of extrapolating the late effects of high-dose exposure to ionizing radiation to the low-dose range, but there is great uncertainty about its validity. The acceptance of LNTM as the dominant probabilistic model have survived to the present day and it is actually the cornerstone of current radiation protection policies. In the last decades, advances in molecular and evolutive biology, cancer immunology, and many epidemiological and animal studies have cast serious doubts about the reliability of the NLTM, as well as suggesting alternative models, like the hormetic theory. Considering the given evidences, a discussion between the involved scientific societies and the regulatory commissions is promtly required in order to to reach a redefiniton of theradiation protection basis, as it would be specially crucial in the medical field


Assuntos
Humanos , Relação Dose-Resposta à Radiação , Hormese/efeitos da radiação , Radiobiologia/métodos , Carcinogênese/efeitos da radiação , Lesões por Radiação/prevenção & controle , 51569/prevenção & controle , Proteção Radiológica/normas , Doses de Radiação , Fracionamento da Dose de Radiação , Modelos Lineares , Medicina Nuclear/métodos , Radiação Ionizante/classificação , Efeitos Adversos de Longa Duração/prevenção & controle , Efeitos da Radiação , Radiometria/métodos
10.
Br J Radiol ; 93(1115): 20200245, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32970457

RESUMO

Not surprisingly, our knowledge of the impact of radiation on the brain has evolved considerably. Decades of work have struggled with identifying the critical cellular targets in the brain, the latency of functional change and understanding how irradiation alters the balance between excitatory and inhibitory circuits. Radiation-induced cell kill following clinical fractionation paradigms pointed to both stromal and parenchymal targets but also defined an exquisite sensitivity of neurogenic populations of newly born cells in the brain. It became more and more apparent too, that acute (days) events transpiring after exposure were poorly prognostic of the late (months-years) waves of radiation injury believed to underlie neurocognitive deficits. Much of these gaps in knowledge persisted as NASA became interested in how exposure to much different radiation types, doses and dose rates that characterize the space radiation environment might impair central nervous system functionality, with possibly negative implications for deep space travel. Now emerging evidence from researchers engaged in clinical, translational and environmental radiation sciences have begun to fill these gaps and have uncovered some surprising similarities in the response of the brain to seemingly disparate exposure scenarios. This article highlights many of the commonalities between the vastly different irradiation paradigms that distinguish clinical treatments from occupational exposures in deep space.


Assuntos
Neoplasias Encefálicas/radioterapia , Encéfalo/efeitos da radiação , Exposição à Radiação/efeitos adversos , Lesões por Radiação/complicações , Voo Espacial , Neoplasias Encefálicas/terapia , Transtornos Cognitivos/etiologia , Humanos , Íons , Transferência Linear de Energia , Doses de Radiação , Exposição à Radiação/prevenção & controle , Lesões por Radiação/prevenção & controle
11.
Medicine (Baltimore) ; 99(33): e21719, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32872052

RESUMO

The study was aimed to evaluate the image quality and radiation dose during female chest computed tomography (CT) screening using organ-based tube current modulation technology X-ray combined applications to reduce exposure (XCARE).Five hundred sixty female individuals undergoing chest CT scan were prospectively enrolled and divided into 4 groups based on body mass index (BMI). Then they were randomly and equally divided into control and experimental subgroup and respectively accepted conventional low-dose and XCARE technology spiral CT scan with same parameters. Signal-to-noise ratio and contrast-to-noise ratio were calculated. The quality of the images was evaluated by 2 radiologists using a 5-point scale.Among experimental subgroups of the 4 BMI groups, Signal-to-noise ratios, CT dose index of volume, dose-length product, effective dose, and contrast-to-noise ratio all displayed significant differences, as well as in control subgroups (P < .001). Both the experimental and control subgroups showed an increasing trend in radiation dose with the increasing of BMI. Parameters of image quality and radiation dose displayed no significant differences between control and experimental subgroups in the 4 groups. In multiple linear regression analysis, age and scanning protocol were not associated with radiation dose (P > .05), while BMI was significantly associated with increased CT dose index of volume (P < .05). The display of the lesions for the patients in the control and experimental subgroups of the 4 groups with different BMIs exhibited no statistically significant difference.The same image quality and radiation dose can be obtained using XCARE technology compared to conventional chest CT scans, which can be used regularly in female patients.Advances in knowledge: Using automatic tube current modulation technology to reduce exposure in breast. In this study, we sought a radiation protection method for sensitive tissue in chest CT screening.


Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Programas de Rastreamento/métodos , Lesões por Radiação/prevenção & controle , Radiografia Torácica/métodos , Tomografia Computadorizada Espiral/métodos , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Melhoria de Qualidade , Doses de Radiação
12.
J Vasc Interv Radiol ; 31(10): 1578-1586, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32861570

RESUMO

PURPOSE: To demonstrate that temporary organ displacement (TOD) by drainage catheter placement and hydrodissection is feasible and reproducible for simulation (SIM) and stereotactic body radiation treatment (SBRT). MATERIALS AND METHODS: Between February 2010 and December 2018, 31 consecutive patients (20 men and 11 women; median age, 59 years; range 20-80 years) received both SIM and SBRT with TOD. The minimum required displacement was 10 mm between the gross tumor volume (GTV) and the organ at risk (OAR). Complete displacement was defined as the ability to displace the OAR from the GTV a minimum of 10 mm across the entire boundary. SIM was performed with hydrodissection on the same day. On the day of SBRT, displacement was reproduced by hydrodissection. Displacement was measured on computed tomography images of TOD, SIM, and SBRT. The drain was removed after SBRT. RESULTS: TOD (hydrodissection) was significantly associated with successful displacement of the OAR from a GTV greater than 10 mm (median, 20 mm vs 4.1 mm, P < .001) and maintained displacement at SIM and SBRT (SIM: 29.4 mm vs 4.1 mm, P < .001; SBRT: 32.4 mm vs 4.1 mm, P < .001). The OAR-GTV boundary showed a median reduction of 35 mm (95% confidence interval, 27.5-37.5 mm) after TOD. TOD achieved complete displacement in 22 of 31 (71%) patients, and 25 of 31 (81%) patients were able to undergo single-fraction ablative SBRT. No patients developed procedure-related complications within 30 days. SIM and SBRT were successful without OAR toxicities within a median of 33 months (range, 3-92 months). CONCLUSIONS: TOD with placement of drain and hydrodissection is technically feasible and safe and maintains displacement for SIM and SBRT.


Assuntos
Cateteres de Demora , Drenagem/instrumentação , Órgãos em Risco , Doses de Radiação , Exposição à Radiação/prevenção & controle , Lesões por Radiação/prevenção & controle , Radiocirurgia , Neoplasias Retroperitoneais/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição à Radiação/efeitos adversos , Lesões por Radiação/etiologia , Radiocirurgia/efeitos adversos , Neoplasias Retroperitoneais/diagnóstico por imagem , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
13.
Medicine (Baltimore) ; 99(34): e21831, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32846829

RESUMO

Adoption of interventional endoscopic procedures is increasing with increasing prevalence of diseases. However, medical radiation exposure is concerning; therefore, radiation protection for medical staff is important. However, there is limited information on the usefulness of an additional lead shielding device during interventional endoscopic procedures. Therefore, we aimed to determine whether an additional lead shielding device protects medical staff from radiation.An X-ray unit (CUREVISTA; Hitachi Medical Systems, Tokyo, Japan) with an over-couch X-ray system was used. Fluoroscopy-associated scattered radiation was measured using a water phantom placed at the locations of the endoscopist, assistant, nurse, and clinical engineer. For each location, measurements were performed at the gonad and thyroid gland/eye levels. Comparisons were performed between with and without the additional lead shielding device and with and without a gap in the shielding device. Additionally, a clinical study was performed with 27 endoscopic retrograde cholangiopancreatography procedures.The scattered radiation dose was lower with than without additional lead shielding at all medical staff locations and decreased by 84.7%, 82.8%, 78.2%, and 83.7%, respectively, at the gonad level and by 89.2%, 86.4%, 91.2%, and 87.0%, respectively, at the thyroid gland/eye level. Additionally, the scattered radiation dose was lower without than with a gap in the shielding device at all locations.An additional lead shielding device could protect medical staff from radiation during interventional endoscopic procedures. However, gaps in protective equipment reduce effectiveness and should be eliminated.


Assuntos
Exposição Ocupacional/prevenção & controle , Exposição à Radiação/prevenção & controle , Proteção Radiológica/instrumentação , Radiografia Intervencionista/efeitos adversos , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Colangiopancreatografia Retrógrada Endoscópica/estatística & dados numéricos , Fluoroscopia/efeitos adversos , Gônadas/efeitos da radiação , Humanos , Traumatismos Ocupacionais/prevenção & controle , Imagens de Fantasmas/estatística & dados numéricos , Equipamentos de Proteção/normas , Doses de Radiação , Lesões por Radiação/prevenção & controle , Proteção Radiológica/métodos , Glândula Tireoide/efeitos da radiação
15.
Br J Radiol ; 93(1113): 20200217, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32706989

RESUMO

The effects of various forms of ionising radiation are known to be mediated by interactions with cellular and molecular targets in irradiated and in some cases non-targeted tissue volumes. Despite major advances in advanced conformal delivery techniques, the probability of normal tissue complication (NTCP) remains the major dose-limiting factor in escalating total dose delivered during treatment. Potential strategies that have shown promise as novel delivery methods in achieving effective tumour control whilst sparing organs at risk involve the modulation of critical dose delivery parameters. This has led to the development of techniques using high dose spatial fractionation (GRID) and ultra-high dose rate (FLASH) which have translated to the clinic. The current review discusses the historical development and biological basis of GRID, microbeam and FLASH radiotherapy as advanced delivery modalities that have major potential for widespread implementation in the clinic in future years.


Assuntos
Fracionamento da Dose de Radiação , Neoplasias/radioterapia , Vasos Sanguíneos/efeitos da radiação , Efeito Espectador , História do Século XX , História do Século XXI , Humanos , Neoplasias/irrigação sanguínea , Neoplasias/imunologia , Órgãos em Risco/efeitos da radiação , Fótons/uso terapêutico , Terapia com Prótons/métodos , Terapia com Prótons/tendências , Lesões por Radiação/prevenção & controle , Radiobiologia , Radioterapia/história , Radioterapia/instrumentação
16.
Med. oral patol. oral cir. bucal (Internet) ; 25(4): e488-e494, jul. 2020. tab
Artigo em Inglês | IBECS | ID: ibc-196501

RESUMO

BACKGROUND: Previous studies have shown that radiotherapy of the head and neck region can cause direct changes in dental structure. This study evaluated the effect of different solutions on the dentin chemical composition and collagen structure of irradiated dentin. MATERIAL AND METHODS: Sixty maxillary canines were distributed in 2 groups (n = 30): non-irradiated and irradiated (radiotherapy: X-rays of 6 MV in 30 cycles of 2 Gy to 60 Gy). The teeth were sectioned, sanded, and polished to obtain 3x3x2 mm fragments, which were redistributed in 3 subgroups (n = 10) according to the treatment employed: chlorhexidine 2% (CL), chitosan 0.2% (QT), and 0.5 M carbodiimide (EDC). The samples were analyzed in FTIR at time zero (T0-control) and after 1 (T1), 3 (T3), and 5 (T5) minutes of immersion in the tested solutions. The data for the areas of the carbonate (C), amide I (AI) bands, and the ratio between the areas of the amide III/proline and hydroxyproline (AIII/PH) bands were analyzed using ANOVA and Tukey test (alpha = 5%).RESULTS: QT showed lower C values at T1, T3, and T5 (P < 0.0001), presenting lower values when compared to CL and EDC subgroups (P < 0.05). AI values at T3 and T5 were higher than T0-control and T1, independently of the radiotherapy and dentin treatment factors (P < 0.05). At T0-control, the AIII/PH ratio was lower in the irradiated group (P < 0.05), whereas the EDC treatment at T1, T3, and T5 and QT at T3 and T5 increased these values (P < 0.05), making them similar to non-irradiated subgroups (P>0.05). CONCLUSIONS: Radiotherapy changes the secondary structure of collagen, and EDC was able to restore collagen integrity after 1 minute of immersion, without changing dentin inorganic composition


No disponible


Assuntos
Humanos , Dentina/efeitos da radiação , Lesões por Radiação/prevenção & controle , Clorexidina/uso terapêutico , Quitosana/uso terapêutico , Carbodi-Imidas/uso terapêutico , Radioterapia/efeitos adversos , Análise de Variância , Estatísticas não Paramétricas , Fatores de Tempo , Propriedades de Superfície , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Imersão
17.
Top Magn Reson Imaging ; 29(3): 135-148, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32568976

RESUMO

The delivery of radiation therapy shares many of the challenges encountered in imaging procedures. As in imaging, such as MRI, organ motion must be reduced to a minimum, often for lengthy time periods, to effectively target the tumor during imaging-guided therapy while reducing radiation dose to nearby normal tissues. For patients, radiation therapy is frequently a stress- and anxiety-provoking medical procedure, evoking fear from negative perceptions about irradiation, confinement from immobilization devices, claustrophobia, unease with equipment, physical discomfort, and overall cancer fear. Such stress can be a profound challenge for cancer patients' emotional coping and tolerance to treatment, and particularly interferes with advanced radiation therapy procedures where active, complex and repetitive high-level cooperation is often required from the patient.In breast cancer, the most common cancer in women worldwide, radiation therapy is an indispensable component of treatment to improve tumor control and outcome in both breast-conserving therapy for early-stage disease and in advanced-stage patients. High technological complexity and high patient cooperation is required to mitigate the known cardiac toxicity and mortality from breast cancer radiation by reducing the unintended radiation dose to the heart from left breast or left chest wall irradiation. To address this, radiation treatment in daily deep inspiration breath hold (DIBH), to create greater distance between the treatment target and the heart, is increasingly practiced. While holding the promise to decrease cardiac toxicity, DIBH procedures often augment patients' baseline stress and anxiety reaction toward radiation treatment. Patients are often overwhelmed by the physical and mental demands of daily DIBH, including the nonintuitive timed and sustained coordination of abdominal thoracic muscles for prolonged breath holding.While technologies, such as DIBH, have advanced to millimeter-precision in treatment delivery and motion tracking, the "human factor" of patients' ability to cooperate and perform has been addressed much less. Both are needed to optimally deliver advanced radiation therapy with minimized normal tissue effects, while alleviating physical and cognitive distress during this challenging phase of breast cancer therapy.This article discusses physical training and psychotherapeutic integrative health approaches, applied to radiation oncology, to leverage and augment the gains enabled by advanced technology-based high-precision radiation treatment in breast cancer. Such combinations of advanced technologies with training and cognitive integrative health interventions hold the promise to provide simple feasible and low-cost means to improve patient experience, emotional outcomes and quality of life, while optimizing patient performance for advanced imaging-guided treatment procedures - paving the way to improve cardiac outcomes in breast cancer survivors.


Assuntos
Neoplasias da Mama/psicologia , Neoplasias da Mama/radioterapia , Cardiotoxicidade/prevenção & controle , Terapia Cognitivo-Comportamental/métodos , Coração/efeitos da radiação , Lesões por Radiação/prevenção & controle , Planejamento da Radioterapia Assistida por Computador/métodos , Suspensão da Respiração , Cardiotoxicidade/etiologia , Feminino , Humanos , Qualidade de Vida , Doses de Radiação , Lesões por Radiação/etiologia , Ensaios Clínicos Controlados Aleatórios como Assunto
18.
Chin J Nat Med ; 18(6): 436-445, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32503735

RESUMO

This study investigated the effects of X-ray irradiation on primary rat cardiac fibroblasts (CFs) and its potential mechanism, as well as whether sodium tanshinone IIA sulfonate (STS) has protective effect on CFs and its possible mechanism. Our data demonstrated that X-rays inhibited cell growth and increased oxidative stress in CFs, and STS mitigated X-ray-induced injury. Enzyme-linked immuno-sorbent assay showed that X-rays increased the levels of secreted angiotensin II (Ang II) and brain natriuretic peptide (BNP). STS inhibited the X-ray-induced increases in Ang II and BNP release. Apoptosis and cell cycle of CFs were analyzed using flow cytometry. X-rays induced apoptosis in CFs, whereas STS inhibited apoptosis in CFs after X-ray irradiation. X-rays induced S-phase cell cycle arrest in CFs, which could be reversed by STS. X-rays increased the expression of phosphorylated-P38/P38, cleaved caspase-3 and caspase-3 as well as decreased the expression of phosphorylated extracellular signal-regulated kinase 1/2 (ERK 1/2)/ERK 1/2 and B cell lymphoma 2 (Bcl-2)/Bcl-2 associated X protein (BAX) in CFs, as shown by Western blotting. STS mitigated the X-ray radiation-induced expression changes of these proteins. In conclusion, our results demonstrated that STS may potentially be developed as a medical countermeasure to mitigate radiation-induced cardiac damage.


Assuntos
Fibroblastos/efeitos dos fármacos , Fibroblastos/efeitos da radiação , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/efeitos da radiação , Fenantrenos/farmacologia , Lesões por Radiação/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
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