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Sorting and measuring blood by cell type is extremely valuable clinically and provides physicians with key information for diagnosing many different disease states including: leukemia, autoimmune disorders, bacterial infections, etc. Despite the value, the present methods are unnecessarily costly and inhibitive particularly in resource poor settings, as they require multiple steps of reagent and/or dye additions and subsequent rinsing followed by manual counting using a hemocytometer, or they require a bulky, expensive equipment such as a flow cytometer. While direct on-paper imaging has been considered challenging, paper substrate offers a strong potential to simplify such reagent/dye addition and rinsing. In this work, three-layer paper-based device is developed to automate such reagent/dye addition and rinsing via capillary action, as well as separating white blood cells (WBCs) from whole blood samples. Direct onpaper imaging is demonstrated using a commercial microscope attachment to a smartphone coupled with a blue LED and 500 nm long pass optical filter. Image analysis is accomplished using an original MATLAB code, to evaluate the total WBC count, as well as differential WBC count, i.e., granulocytes (primarily neutrophils) vs. agranulocytes (primarily lymphocytes). Only a finger-prick of whole blood is required for this assay. The total assay time from finger-prick to data collection is under five minutes. Comparison with a hemocytometry-based manual counting corroborates the accuracy and effectiveness of the proposed method. This approach could be potentially used to help make blood cell counting technologies more readily available, especially in resource poor, point-of-care settings.
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PURPOSE: To evaluate the association between traditional clinical high-risk features of uveal melanoma patients and gene expression profile (GEP). METHODS: This was a retrospective, single-center, case series of patients with uveal melanoma. Eighty-three patients met inclusion criteria for the study. Patients were examined for the following clinical risk factors: drusen/retinal pigment epithelium (RPE) changes, vascularity on B-scan, internal reflectivity on A-scan, subretinal fluid (SRF), orange pigment, apical tumor height/thickness, and largest basal dimensions (LBD). A novel point system was created to grade the high-risk clinical features of each tumor. Further analyses were performed to assess the degree of association between GEP and each individual risk factor, total clinical risk score, vascularity, internal reflectivity, American Joint Committee on Cancer (AJCC) tumor stage classification, apical tumor height/thickness, and LBD. RESULTS: Of the 83 total patients, 41 were classified as GEP class 1A, 17 as class 1B, and 25 as class 2. The presence of orange pigment, SRF, low internal reflectivity and vascularity on ultrasound, and apical tumor height/thickness ≥ 2 mm were not statistically significantly associated with GEP class. Lack of drusen/RPE changes demonstrated a trend toward statistical association with GEP class 2 compared to class 1A/1B. LBD and advancing AJCC stage was statistically associated with higher GEP class. CONCLUSIONS: In this cohort, AJCC stage classification and LBD were the only clinical features statistically associated with GEP class. Clinicians should use caution when inferring the growth potential of melanocytic lesions solely from traditional funduscopic and ultrasonographic risk factors without GEP data.
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Biomarcadores Tumorais/genética , Perfilação da Expressão Gênica/métodos , Melanoma/genética , Estadiamento de Neoplasias , Neoplasias Uveais/genética , Adulto , Idoso , Biomarcadores Tumorais/biossíntese , Biópsia por Agulha Fina , Corioide/metabolismo , Corioide/patologia , Feminino , Seguimentos , Humanos , Masculino , Melanoma/classificação , Melanoma/diagnóstico , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Transcriptoma , Neoplasias Uveais/classificação , Neoplasias Uveais/diagnósticoRESUMO
CASE: A 17-year-old adolescent boy with Gross Motor Function Classification System 5 cerebral palsy and neuromuscular scoliosis underwent posterior spinal fusion and segmental spinal instrumentation from T3 to the pelvis. He developed a right ischial pressure injury a few months postoperatively, which persisted despite nonoperative measures. He subsequently underwent an ipsilateral transiliac-shortening osteotomy 16 months after spinal surgery to treat his residual pelvic obliquity and the ischial pressure injury, which healed completely. At the 1-year follow-up visit, there were no further signs of pressure injury. CONCLUSION: This case report describes transiliac-shortening osteotomy as a viable treatment option for non-healing ischial pressure injuries secondary to fixed pelvic obliquity.
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Ísquio , Osteotomia , Úlcera por Pressão , Humanos , Masculino , Adolescente , Osteotomia/métodos , Ísquio/lesões , Ísquio/cirurgia , Úlcera por Pressão/cirurgia , Úlcera por Pressão/etiologia , Fusão Vertebral/métodos , Paralisia Cerebral/cirurgia , Paralisia Cerebral/complicações , Escoliose/cirurgia , Ílio/cirurgiaRESUMO
There are no assays for detecting B. burgdorferi antigen in blood of infected Lyme disease individuals. Here, we provide proof-of-principle evidence that we can quantify B. burgdorferi antigen in spiked blood using a portable smartphone-based fluorescence microscope that measures immunoagglutination on a paper microfluidic chip. We targeted B. burgdorferi OspA to develop a working prototype and added examples of two antigens (OspC and VlsE) that have diagnostic value for discrimination of Lyme disease stage. Using an extensively validated monoclonal antibody to OspA (LA-2), detection of OspA antigen had a broad linear range up to 100 pg/mL in 1% blood and the limit of detection (LOD) was 100 fg/mL (= 10 pg/mL in undiluted blood), which was 1000 times lower than our target of 10 ng/mL. Analysis of the two other targets was done using polyclonal and monoclonal antibodies. OspC antigen was detected at LOD 100 pg/mL (= 10 ng/mL of undiluted blood) and VlsE antigen was detected at LOD 1-10 pg/mL (= 0.1-1 ng/mL of undiluted blood). The method is accurate and was performed in 20 min from sample to answer. When optimized for detecting several B. burgdorferi antigens, this assay may differentiate active from past infections and facilitate diagnosis of Lyme disease in the initial weeks of infection, when antibody presence is typically below the threshold to be detected by serologic methods.
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Técnicas Biossensoriais , Antígenos de Grupos Sanguíneos , Borrelia burgdorferi , Doença de Lyme , Humanos , Imunoensaio , Antígenos de Bactérias , Anticorpos Monoclonais , Doença de Lyme/diagnósticoRESUMO
Airborne SARS-CoV-2 transmission represents a significant route for possible human infection that is not yet fully understood. Viruses in droplets and aerosols are difficult to detect because they are typically present in low amounts. In addition, the current techniques used, such as RT-PCR and virus culturing, require large amounts of time to get results. Biosensor technology can provide rapid, handheld, and point-of-care systems that can identify virus presence quickly and accurately. This paper reviews the background of airborne virus transmission and the characteristics of SARS-CoV-2, its relative risk for transmission even at distances greater than the currently suggested 6 feet (or 2 m) physical distancing. Publications on biosensor technology that may be applied to the detection of airborne SARS-CoV-2 and other respiratory viruses are also summarized. Based on the current research we believe that there is a pressing need for continued research into handheld and rapid methods for sensitive collection and detection of airborne viruses. We propose a paper-based microfluidic chip and immunofluorescence assay as one method that could be investigated as a low-cost and portable option.
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Técnicas Biossensoriais , COVID-19 , Vírus , Aerossóis , Humanos , SARS-CoV-2RESUMO
SARS, a new type of respiratory disease caused by SARS-CoV, was identified in 2003 with significant levels of morbidity and mortality. The recent pandemic of COVID-19, caused by SARS-CoV-2, has generated even greater extents of morbidity and mortality across the entire world. Both SARS-CoV and SARS-CoV-2 spreads through the air in the form of droplets and potentially smaller droplets (aerosols) via exhaling, coughing, and sneezing. Direct detection from such airborne droplets would be ideal for protecting general public from potential exposure before they infect individuals. However, the number of viruses in such droplets and aerosols is too low to be detected directly. A separate air sampler and enough collection time (several hours) are necessary to capture a sufficient number of viruses. In this work, we have demonstrated the direct capture of the airborne droplets on the paper microfluidic chip without the need for any other equipment. 10% human saliva samples were spiked with the known concentration of SARS-CoV-2 and sprayed to generate liquid droplets and aerosols into the air. Antibody-conjugated submicron particle suspension is then added to the paper channel, and a smartphone-based fluorescence microscope isolated and counted the immunoagglutinated particles on the paper chip. The total capture-to-assay time was <30 min, compared to several hours with the other methods. In this manner, SARS-CoV-2 could be detected directly from the air in a handheld and low-cost manner, contributing to slowing the spread of SARS-CoV-2. We can presumably adapt this technology to a wide range of other respiratory viruses.
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Técnicas Biossensoriais , COVID-19 , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Aerossóis , Humanos , Microfluídica , SARS-CoV-2 , SmartphoneRESUMO
Saliva specimens have drawn interest for diagnosing respiratory viral infections due to their ease of collection and decreased risk to healthcare providers. However, rapid and sensitive immunoassays have not yet been satisfactorily demonstrated for such specimens due to their viscosity and low viral loads. Using paper microfluidic chips and a smartphone-based fluorescence microscope, we developed a highly sensitive, low-cost immunofluorescence particulometric SARS-CoV-2 assay from clinical saline gargle samples. We demonstrated the limit of detection of 10 ag/µL. With easy-to-collect saline gargle samples, our clinical sensitivity, specificity, and accuracy were 100%, 86%, and 93%, respectively, for n = 27 human subjects with n = 13 RT-qPCR positives.
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Respiratory viruses, especially coronaviruses, have resulted in worldwide pandemics in the past couple of decades. Saliva-based paper microfluidic assays represent an opportunity for noninvasive and rapid screening, yet both the sample matrix and test method come with unique challenges. In this work, we demonstrated the rapid and sensitive detection of SARS-CoV-2 from saliva samples, which could be simpler and more comfortable for patients than existing methods. Furthermore, we systematically investigated the components of saliva samples that affected assay performance. Using only a smartphone, an antibody-conjugated particle suspension, and a paper microfluidic chip, we made the assay user-friendly with minimal processing. Unlike the previously established flow rate assays that depended solely on the flow rate or distance, this unique assay analyzes the flow profile to determine infection status. Particle-target immunoagglutination changed the surface tension and subsequently the capillary flow velocity profile. A smartphone camera automatically measured the flow profile using a Python script, which was not affected by ambient light variations. The limit of detection (LOD) was 1 fg/µL SARS-CoV-2 from 1% saliva samples and 10 fg/µL from simulated saline gargle samples (15% saliva and 0.9% saline). This method was highly specific as demonstrated using influenza A/H1N1. The sample-to-answer assay time was <15 min, including <1-min capillary flow time. The overall accuracy was 89% with relatively clean clinical saline gargle samples. Despite some limitations with turbid clinical samples, this method presents a potential solution for rapid mass testing techniques during any infectious disease outbreak as soon as the antibodies become available.
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Técnicas Biossensoriais , COVID-19 , Vírus da Influenza A Subtipo H1N1 , COVID-19/diagnóstico , Humanos , Microfluídica , SARS-CoV-2 , SmartphoneRESUMO
Purpose: The aim of this study was to demonstrate that uveal melanoma (UM) treated with eye plaque brachytherapy (EPB) with intra-operative ultrasound (IOUS) guidance results in increased local control. Material and methods: A retrospective study was conducted among 212 patients with 214 UM tumors treated by iodine-125 EPB with IOUS guidance from 2013 to 2019. 85 Gy was prescribed to tumor apical height or 5 mm from inner sclera, whichever was greater. Lesions were treated to 95% of 85 Gy at 2 mm margin from tumor edge. Local failure (LF), distant metastasis (DM), and radiation-related toxicity were recorded. Results: Median tumor apical height was 3.3 mm. COMS stage was 90 small (42.1%), 81 medium (37.9%), and 43 large (20.1%). Most patients had gene expression profile (GEP) class available, with 119 (55.6%), 30 (14.0%), 55 (25.7%) cases classified as 1A, 1B, and 2, respectively. Median dose at apex for tumor height > 5 mm and ≤ 5 mm was 85.0 Gy and 120.6 Gy, respectively. Outcomes data for 180 patients with over 12 months follow-up were reported. Mean follow-up was 37.3 months. Rates of LF and DM were 0.0% and 12.2%, respectively. Actuarial estimates of 5-year DM for class 1A, 1B, and 2 tumors were 2.5%, 0.0%, and 57.8%, respectively. 87 patients (48.3%) developed radiation-related toxicities. Conclusions: The excellent local control rate amongst lesions ranging across all sizes and GEP classes emphasizes the importance of image-guided brachytherapy with IOUS. We report favorable 5-year DM rates compared to established rates. Acceptable rate and severity of radiation-related toxicities were observed.
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Oil spills can be environmentally devastating and result in unintended economic and social consequences. An important element of the concerted effort to respond to spills includes the ability to rapidly classify and characterize oil spill samples, preferably on-site. An easy-to-use, handheld sensor is developed and demonstrated in this work, capable of classifying oil spills rapidly on-site. Our device uses the computational power and affordability of a Raspberry Pi microcontroller and a Pi camera, coupled with three ultraviolet light emitting diodes (UV-LEDs), a diffraction grating, and collimation slit, in order to collect a large data set of UV fluorescence fingerprints from various oil samples. Based on a 160-sample (in 5x replicates each with slightly varied dilutions) database this platform is able to classify oil samples into four broad categories: crude oil, heavy fuel oil, light fuel oil, and lubricating oil. The device uses principal component analysis (PCA) to reduce spectral dimensionality (1203 features) and support vector machine (SVM) for classification with 95% accuracy. The device is also able to predict some physiochemical properties, specifically saturate, aromatic, resin, and asphaltene percentages (SARA) based off linear relationships between different principal components (PCs) and the percentages of these residues. Sample preparation for our device is also straightforward and appropriate for field deployment, requiring little more than a Pasteur pipette and not being affected by dilution factors. These properties make our device a valuable field-deployable tool for oil sample analysis.
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Petróleo/análise , Petróleo/classificação , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Fenômenos Químicos , Bases de Dados Factuais , Monitoramento Ambiental/métodos , Óleos Combustíveis/análise , Poluição por Petróleo/análise , Espectrometria de Fluorescência/métodosRESUMO
BACKGROUND: Assessments of human movement are clinically important. However, accurate measurements are often unavailable due to the need for expensive equipment or intensive processing. For orthotists and therapists, shank-to-vertical angle is one critical measure used to assess gait and guide prescriptions. Smartphone-based sensors may provide a widely available platform to expand access to this measurement. OBJECTIVES: Assess accuracy and repeatability of smartphone-based measurement of shank-to-vertical angle compared to marker-based 3D motion analysis. STUDY DESIGN: Repeated-measures. METHODS: Four licensed clinicians (two physical therapists and two orthotists) measured shank-to-vertical angle during gait with a smartphone attached to the anterior or lateral shank surface of unimpaired adults. We compared the shank-to-vertical angle calculated from the smartphone's inertial measurement unit to marker-based measurements. Each clinician completed three sessions/day on two days with each participant to assess repeatability. RESULTS: Average absolute differences in shank-to-vertical angle measured with a smartphone versus marker-based 3D motion analysis during gait were 0.67 ± 0.25° and 4.89 ± 0.72°, with anterior or lateral smartphone positions, respectively. The inter- and intra-day repeatability of shank-to-vertical angle were within 2° for both smartphone positions. CONCLUSIONS: Smartphone sensors can be used to measure shank-to-vertical angle with high accuracy and repeatability during unimpaired gait, providing a widely available tool for quantitative gait assessments. CLINICAL RELEVANCE: Smartphone sensors demonstrated high accuracy and repeatability for monitoring shank-to-vertical angle during gait. Measurement of shank-to-vertical angle from the front of the shank was more accurate than the side of the shank. Smartphones may expand access to quantitative assessments of gait.
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Análise da Marcha/instrumentação , Perna (Membro)/fisiologia , Smartphone/instrumentação , Dispositivos Eletrônicos Vestíveis , Adulto , Fenômenos Biomecânicos , Feminino , Voluntários Saudáveis , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
PURPOSE: To assess the utility of FDG-PET in anal cancer for staging and impact on radiotherapy planning (RTP), response and detection of recurrent disease. METHODS AND MATERIALS: Fifty histopathological anal cancer patients were reviewed between 1996 and 2006. The median age was 58 years (range 36-85) with 19 males:31females. Clinical assessment with CT was compared to PET. Impact on management, disease response, recurrence and metastases was evaluated. RESULTS: The non-PET staging was Stage I(8), Stage II(18), Stage III(22), and Stage IV(2)s. The primary was strongly FDG avid in 98% with non-excised tumors compared to CT (58%). PET upstaged 17% with unsuspected pelvic/inguinal nodal disease. Pre-treatment PET identified 11 additional by involved nodal groups in 48 patients causing RTP amendments in 19%. Post-treatment PETs at median 17 weeks (range 9-28) showed complete responses in 20 (80%) and 5 (20%) partial responses (PR). PRs were biopsy positive in 2 and negative in 3. Fifteen had follow-up scans of which all nine PETs detected recurrences were pathologically confirmed. CONCLUSIONS: Anal cancer is FDG-PET avid. PET upstages 17% and changes the RTP in 19%. PET can aid in anal cancer staging and identification of residual disease, recurrent/metastatic disease but warrants further prospective studies.
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Neoplasias do Ânus/diagnóstico por imagem , Carcinoma de Células Escamosas/diagnóstico por imagem , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Ânus/radioterapia , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/secundário , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-IdadeRESUMO
Metals and pesticides are common pollutants and the modulation of biomarkers can indicate sub-lethal influences on the physiology of organisms inhabiting impacted aquatic systems. We examined the effects of mercury and the organophosphate pesticide dimethoate on EROD, MROD, glutathione S-transferase (GST), acetylcholine esterase (AChE), metallothionein (MT) and glutathione (GSH) in the signal crayfish (Pacifastacus leniusculus). Crayfish were injected with mercury chloride or dimethoate (0.3, 0.6, 0.9⯵gâ¯kg-1) and dissected after 72â¯h. EROD activity in the hepatopancreas did not change in response to mercury chloride treatment but exhibited a dose dependent decrease at all concentrations of dimethoate tested. MROD (hepatopancreas) exhibited a significant decrease at the 0.9⯵gâ¯kg-1 treatment for both chemicals. GST (hepatopancreas) demonstrated a significant dose dependent decrease at all concentrations of both mercury chloride and dimethoate. AChE (tail muscle) decreased at the 0.6 and 0.9⯵gâ¯kg-1 concentrations of dimethoate and 0.9⯵gâ¯kg-1 mercury chloride. In gill tissue, MT increased in response to 0.3 and 0.6⯵gâ¯kg-1 of mercury chloride but no effect was observed at the 0.9⯵gâ¯kg-1 concentration of mercury chloride or any concentrations of dimethoate tested. MT did not change in response to mercury or dimethoate in tail tissue. Furthermore, neither chemical modulated GSH concentrations. Our results indicate that, apart from GSH, these markers are sensitive to the pollutants tested and that animals exposed in the wild are potentially compromised in their ability to detoxify environmental contaminants and carry out normal cellular processes.
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Astacoidea/enzimologia , Dimetoato/toxicidade , Mercúrio/toxicidade , Acetilcolinesterase/efeitos dos fármacos , Animais , Astacoidea/efeitos dos fármacos , Brânquias , Glutationa/efeitos dos fármacos , Glutationa Transferase/efeitos dos fármacos , Hepatopâncreas/efeitos dos fármacos , Inseticidas/farmacologia , Mercúrio/farmacologia , Metalotioneína/efeitos dos fármacos , Distribuição TecidualRESUMO
INTRODUCTION: Conventional clinical staging for prostate cancer has many limitations. This study evaluates the impact of adding MRI scans to conventional clinical staging for guiding decisions about radiotherapy target coverage. METHODS: This was a retrospective review of 115 patients who were treated between February 2002 and September 2005 with radical radiotherapy for prostate cancer. All patients had MRI scans approximately 2 weeks before the initiation of radiotherapy. The T stage was assessed by both conventional clinical methods (cT-staging) as well as by MRI (mT-staging). The radiotherapy target volumes were determined first based on cT-staging and then taking the additional mT staging into account. The number of times extracapsular extension or seminal vesicle invasion was incorporated into target volumes was quantified based on both cT-staging and the additional mT-staging. RESULTS: Extracapsular extension was incorporated into target volumes significantly more often with the addition of mT-staging (46 patients (40%) ) compared with cT-staging alone (37 patients (32%) ) (P = 0.002). Seminal vesicle invasion was incorporated into target volumes significantly more often with the addition of mT-staging (21 patients (18%) ) compared with cT-staging alone (three patients (3%) ) (P < 0.001). A total of 23 patients (20%) had changes to their target coverage based on the mT-staging. CONCLUSIONS: MRI scans can significantly change decisions about target coverage in radical radiotherapy for prostate cancer.
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Algoritmos , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia , Radioterapia Guiada por Imagem/métodos , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
PURPOSE: To determine an appropriate clinical target volume for partial breast radiation therapy (PBRT) based on the spatial distribution of residual invasive and in situ carcinoma after wide local excision (WLE) for early breast cancer or ductal carcinoma in situ (DCIS). METHODS AND MATERIALS: We performed a prospective pathologic study of women potentially eligible for PBRT who had re-excision and/or completion mastectomy after WLE for early breast cancer or DCIS. A pathologic assessment protocol was used to determine the maximum radial extension (MRE) of residual carcinoma from the margin of the initial surgical cavity. Women were stratified by the closest initial radial margin width: negative (>1 mm), close (>0 mm and ≤ 1 mm), or involved. RESULTS: The study population was composed of 133 women with a median age of 59 years (range, 27-82 years) and the following stage groups: 0 (13.5%), I (40.6%), II (38.3%), and III (7.5%). The histologic subtypes of the primary tumor were invasive ductal carcinoma (74.4%), invasive lobular carcinoma (12.0%), and DCIS alone (13.5%). Residual carcinoma was present in the re-excision and completion mastectomy specimens in 55.4%, 14.3%, and 7.2% of women with an involved, close, and negative margin, respectively. In the 77 women with a noninvolved radial margin, the MRE of residual disease, if present, was ≤ 10 mm in 97.4% (95% confidence interval 91.6-99.5) of cases. Larger MRE measurements were significantly associated with an involved margin (P<.001), tumor size >30 mm (P=.03), premenopausal status (P=.03), and negative progesterone receptor status (P=.05). CONCLUSIONS: A clinical target volume margin of 10 mm would encompass microscopic residual disease in >90% of women potentially eligible for PBRT after WLE with noninvolved resection margins.
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Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/química , Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/química , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/radioterapia , Carcinoma Intraductal não Infiltrante/química , Carcinoma Intraductal não Infiltrante/patologia , Carcinoma Intraductal não Infiltrante/radioterapia , Carcinoma Intraductal não Infiltrante/cirurgia , Carcinoma Lobular/química , Carcinoma Lobular/patologia , Carcinoma Lobular/radioterapia , Feminino , Humanos , Mastectomia/métodos , Pessoa de Meia-Idade , Neoplasia Residual , Estudos Prospectivos , Reoperação , Tamanho da Amostra , Carga TumoralRESUMO
PURPOSE: The purpose of this study was to compare and evaluate radiotherapy treatment plans using volumetric modulated arc therapy (VMAT) and intensity modulated radiotherapy (IMRT) for post-prostatectomy radiotherapy. METHODS AND MATERIALS: The quality of radiotherapy plans for 10 patients planned and treated with a seven-field IMRT technique for biochemical failure post-prostatectomy were subsequently compared with 10 prospectively planned single-arc VMAT plans using the same computed tomography data set and treatment planning software. Plans were analysed using parameters to assess for target volume coverage, dose to organs at risk (OAR), biological outcomes, dose conformity and homogeneity, as well as the total monitor units (MU), planning and treatment efficiency. RESULTS: The mean results for the study population are reported for the purpose of comparison. For IMRT, the median dose to the planning target volume, V(95%) and D(95%) was 71.1 Gy, 98.9% and 68.3 Gy compared with 71.2 Gy, 99.2% and 68.6 Gy for VMAT. There was no significant difference in the conformity index or homogeneity index. The VMAT plans achieved better sparing of the rectum and the left and right femora with a reduction in the median dose by 7.9, 6.3 and 3.6 Gy, respectively. The total number of monitor units (MU) was reduced by 24% and treatment delivery time by an estimated 3 min per fraction without a significant increase in planning requirements. CONCLUSIONS: VMAT can achieve post-prostatectomy radiotherapy plans of comparable quality to IMRT with the potential to reduce dose to OAR and improve the efficiency of treatment delivery.