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1.
J Oncol Pharm Pract ; 30(1): 127-141, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37122190

RESUMEN

PURPOSE: Oncology care continues to evolve at a rapid pace including provision of infusion-based care. There is currently a lack of robust metrics around oncology infusion centers and pharmacy practice. The workgroup completed a nationwide survey to learn about oncology-based infusion pharmacy services offered. The objective was to highlight consistent, measureable oncology-based infusion pharmacy metrics that will provide a foundation to describe overall productivity including emphasis on high patient-safety standards. METHODS: A nationwide survey was developed via a workgroup within the Vizient Pharmacy Cancer Care Group beginning in April 2019 and conducted electronically via the Vizient Pharmacy Network from September to November 2020. The survey was designed to capture a number of key metrics related to oncology-based infusion pharmacy services. RESULTS: Forty-one sites responded to the survey. Responses highlighted hours of operation (median = 11.5), number of infusion chairs (median = 45). Staffing metrics included 7.1 pharmacist full-time equivalent (FTE) and 7.6 technician FTE per week. 80.5% of sites had cleanrooms and 95.1% reported both hazardous and nonhazardous compounding hoods. 68.3% of sites reported using intravenous (IV) technology, 50.0% measured turnaround time, and 31.4% prepared treatment medications in advance. CONCLUSION: There was variability among oncology infusion pharmacy practices in regard to survey responses among sites. The survey results highlight the need for standardization of established productivity metrics across oncology infusion pharmacies in order to improve efficiency and contain costs in the changing oncology landscape. The survey provides insight into oncology infusion pharmacy practices nationwide and provides information for pharmacy leaders to help guide their practices.


Asunto(s)
Servicios Farmacéuticos , Farmacias , Farmacia , Humanos , Oncología Médica , Farmacéuticos , Encuestas y Cuestionarios , Bombas de Infusión
2.
Phys Chem Chem Phys ; 21(45): 25431-25438, 2019 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-31712786

RESUMEN

The relationship between the electronic structure of CaO and the binding energy, BE, shifts between surface and bulk atoms is examined and the physical origins of these shifts are established. Furthermore, the contribution of covalent mixing to the interaction, including the energetic importance, is investigated and found to be small. In particular, the small shift between surface and bulk O(1s) BEs is shown to originate from changes in the polarizable charge distribution of surface O anions. This relationship, which is relevant for the catalytic properties of CaO, follows because the BE shifts are dominated by initial state contributions and the relaxation in response to the core-ionization is similar for bulk and surface. In order to explain the dominance of initial state effects for the BE shifts, the relaxation is decomposed into atomic and extra-atomic contributions. The bonding and the core-level BE shifts have been studied using cluster models of CaO with Hartree-Fock wavefunctions. The theoretical shifts are compared with X-ray photoelectron spectroscopy measurements where both angular resolution and incident photon energy have been used to distinguish surface and bulk ionization.

3.
Vet Clin North Am Equine Pract ; 34(3): 461-471, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30447765

RESUMEN

An accurate and timely diagnosis of the systemic and local tissue influences of a wound are essential to target successful treatment measures and reach the best result for an affected horse. A complete physical examination should be completed for any wounded horse and appropriate systemic therapies instituted. Visual and manipulative examinations aid in the complete understanding of wounded tissues. Imaging and invasive diagnostic techniques also have value in determining the extent of a wound. Considering what tissues are involved from an inside-out perspective can assist in developing a complete diagnosis.


Asunto(s)
Extremidades/lesiones , Enfermedades de los Caballos/diagnóstico , Heridas y Lesiones/veterinaria , Animales , Caballos , Examen Físico/veterinaria , Heridas y Lesiones/diagnóstico
4.
Vet Clin North Am Equine Pract ; 33(2): 331-342, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28551286

RESUMEN

Early recognition and treatment of congenital and acquired flexural deformities of the carpi and fetlocks of foals can lead to conformation correction and an athletic future. Treatment is often based on rigid external coaptation assisted by systemic medical treatment. Foals that readily respond to treatment and correct conformation faults can have normal adult athletic expectations.


Asunto(s)
Carpo Animal/anomalías , Enfermedades de los Caballos/congénito , Enfermedades de los Caballos/etiología , Deformidades Adquiridas de la Articulación/veterinaria , Deformidades Congénitas de las Extremidades/veterinaria , Animales , Animales Recién Nacidos , Enfermedades de los Caballos/diagnóstico , Enfermedades de los Caballos/terapia , Caballos , Deformidades Adquiridas de la Articulación/diagnóstico , Deformidades Adquiridas de la Articulación/terapia , Deformidades Congénitas de las Extremidades/diagnóstico , Deformidades Congénitas de las Extremidades/terapia
5.
Biol Sport ; 31(2): 85-93, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24899771

RESUMEN

The final tournament of the UEFA European Football Championship is one of the top sporting events in the world, and a high-profile event of this kind requires a well-planned and well-executed anti-doping programme to ensure the integrity of results in the competition. UEFA EURO 2012 presented a unique logistical challenge, with the tournament spread across two countries, both covering a large geographical area. This paper discusses the planning and delivery of both the pre tournament out-of-competition (OOC) testing programme and the in-competition (IC) programme, as well as reviewing the activities of doping control officers (DCOs), the whereabouts programme and assessing the sample collection and transport process. The analytical approach applied is also discussed, along with an overview of the distribution of T/E ratios and blood parameters.

6.
EES Catal ; 2(1): 311-323, 2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-38222061

RESUMEN

Electrochemical reduction of CO2 (CO2RR) is an attractive technology to reintegrate the anthropogenic CO2 back into the carbon cycle driven by a suitable catalyst. This study employs highly efficient multi-carbon (C2+) producing Cu2O nanocubes (NCs) decorated with CO-selective Au nanoparticles (NPs) to investigate the correlation between a high CO surface concentration microenvironment and the catalytic performance. Structure, morphology and near-surface composition are studied via operando X-ray absorption spectroscopy and surface-enhanced Raman spectroscopy, operando high-energy X-ray diffraction as well as quasi in situ X-ray photoelectron spectroscopy. These operando studies show the continuous evolution of the local structure and chemical environment of our catalysts during reaction conditions. Along with its alloy formation, a CO-rich microenvironment as well as weakened average CO binding on the catalyst surface during CO2RR is detected. Linking these findings to the catalytic function, a complex compositional interplay between Au and Cu is revealed in which higher Au loadings primarily facilitate CO formation. Nonetheless, the strongest improvement in C2+ formation appears for the lowest Au loadings, suggesting a beneficial role of the Au-Cu atomic interaction for the catalytic function in CO2RR. This study highlights the importance of site engineering and operando investigations to unveil the electrocatalyst's adaptations to the reaction conditions, which is a prerequisite to understand its catalytic behavior.

7.
Energy Environ Sci ; 17(5): 2046-2058, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38449571

RESUMEN

The production of green hydrogen through alkaline water electrolysis is the key technology for the future carbon-neutral industry. Nanocrystalline Co3O4 catalysts are highly promising electrocatalysts for the oxygen evolution reaction and their activity strongly benefits from Fe surface decoration. However, limited knowledge of decisive catalyst motifs at the atomic level during oxygen evolution prevents their knowledge-driven optimization. Here, we employ a variety of operando spectroscopic methods to unveil how Fe decoration increases the catalytic activity of Co3O4 nanocatalysts as well as steer the (near-surface) active state formation. Our study shows a link of the termination-dependent Fe decoration to the activity enhancement and a significantly stronger Co3O4 near-surface (structural) adaptation under the reaction conditions. The near-surface Fe- and Co-O species accumulate an oxidative charge and undergo a reversible bond contraction during the catalytic process. Moreover, our work demonstrates the importance of low coordination surface sites on the Co3O4 host to ensure an efficient Fe-induced activity enhancement, providing another puzzle piece to facilitate optimized catalyst design.

8.
Undersea Hyperb Med ; 40(6): 499-504, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24377192

RESUMEN

INTRODUCTION: Hyperbaric oxygen (HBO2) therapy has been used to promote viability of compromised flaps despite a paucity of supportive clinical evidence. This study provides an in-depth characterization of hyperbaric medicine to promote flap survival and identifies treatment variables associated with positive clinical outcomes. METHODS: A retrospective review was conducted of patients who received HBO2 therapy for a failing or threatened post-reconstructive flap from 5/30/2008 through 4/30/2012. Medical records were reviewed to collect patient characteristics, hyperbaric oxygen therapy details, and clinical outcomes. Descriptive and comparative statistics were utilized. RESULTS: Ninety-one patients underwent HBO2 therapy during this time period, with 15 patients meeting the selection criteria. Flap survival was achieved in 11 patients (73.3%). Of those successfully treated, four (36.4%) healed completely, and seven (63.6%) demonstrated marked improvement. Patients who were treated successfully demonstrated an average improvement in flap area of 68.3%. Variables significantly associated with a favorable treatment outcome included a high percentage of treatment completion (p = 0.022) and high pretreatment transcutaneous oxygen measurements (p = 0.05). Smoking was a negative factor (p = 0.011). CONCLUSION: This study provides clinical data characterizing and supporting the application of hyperbaric medicine to aid in the viability of compromised flaps.


Asunto(s)
Supervivencia de Injerto , Oxigenoterapia Hiperbárica/métodos , Colgajos Quirúrgicos/fisiología , Adolescente , Adulto , Anciano , Femenino , Humanos , Oxigenoterapia Hiperbárica/efectos adversos , Masculino , Persona de Mediana Edad , Cooperación del Paciente , Estudios Retrospectivos , Factores de Riesgo , Fumar/efectos adversos , Adulto Joven
9.
PLoS One ; 18(5): e0285150, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37172062

RESUMEN

Oaks (Quercus spp.) are widespread hardwood trees in the Northern Hemisphere and of high ecological, economic, and social values. Optimal experimental design of genetic trials is essential for accurate estimates of genetic parameters and improving the genetic merit of breeding stock. Here, we evaluate the use of post hoc row-column factors combined with spatial adjustment to improve genetic analyses of parents and individual trees in field progeny tests of plantation hardwoods, using cherrybark oak (Quercus pagoda Raf.) as an example. For tree height, post hoc incomplete blocking reduced ~14% more of the within-block environmental variance compared to the randomized complete block design (RCBD) model. Incomplete blocking also improved the heritability estimates for height by 7% to 14% compared to the original RCBD model. No clinal trend for growth breeding values was identified due to provenances. Our approach warrants the initial selection for height as early as age ~10 based on its moderate narrow-sense heritability of 0.2; however, diameter and volume need longer evaluation times. The post hoc incomplete blocking is more efficient and promising to improve the genetic analysis of Q. pagoda to minimize the environmental heterogeneity influences. Adjusting competition and spatial effects, including the distance principal components and autoregressive residual structure notably improves the model fit based on the observed reductions in AICs and BICs. Employing our approach is promising for hardwood genetic improvement in the southern USA.


Asunto(s)
Quercus , Quercus/genética , Proyectos de Investigación , Fitomejoramiento , Árboles
10.
Can Vet J ; 53(4): 378-82, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23024382

RESUMEN

Visualization of colonic mesenteric vasculature during transabdominal ultrasonographic examination of horses with colic can be a predictor of right dorsal displacement of the large colon or 180° large colon volvulus, or both. Medical records of 82 horses having had surgical treatment of colic and having received a transabdominal ultrasonographic examination on admission were reviewed. Colonic mesenteric vessels were sonographically identified coursing laterally on the right side of the abdomen in 24 of the 82 cases. Horses with colonic vessels identified on ultrasound were 32.5 times more likely to be diagnosed at surgery with either large colon right dorsal displacement or 180° large colon volvulus than those in which vessels were not seen (P < 0.001). Visualization of colonic mesenteric vessels on ultrasound provided a sensitivity of 67.7%, specificity of 97.9%, positive predictive value of 95.8%, and negative predictive value of 81% for large colon right dorsal displacement or 180° large colon volvulus, or both.


Asunto(s)
Enfermedades del Colon/veterinaria , Enfermedades de los Caballos/diagnóstico por imagen , Vólvulo Intestinal/veterinaria , Mesenterio/irrigación sanguínea , Mesenterio/diagnóstico por imagen , Animales , Cólico/diagnóstico , Cólico/diagnóstico por imagen , Cólico/veterinaria , Enfermedades del Colon/diagnóstico , Enfermedades del Colon/diagnóstico por imagen , Diagnóstico Diferencial , Femenino , Enfermedades de los Caballos/diagnóstico , Caballos , Vólvulo Intestinal/diagnóstico por imagen , Masculino , Valor Predictivo de las Pruebas , Ultrasonografía
11.
J Org Chem ; 75(4): 1155-61, 2010 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-20102230

RESUMEN

A potent reversible inhibitor of the cysteine protease cathepsin-S was prepared on large scale using a convergent synthetic route, free of chromatography and cryogenics. Late-stage peptide coupling of a chiral urea acid fragment with a functionalized aminonitrile was employed to prepare the target, using 2-hydroxypyridine as a robust, nonexplosive replacement for HOBT. The two key intermediates were prepared using a modified Strecker reaction for the aminonitrile and a phosphonation-olefination-rhodium-catalyzed asymmetric hydrogenation sequence for the urea. A palladium-catalyzed vinyl transfer coupled with a Claisen reaction was used to produce the aldehyde required for the side chain. Key scale up issues, safety calorimetry, and optimization of all steps for multikilogram production are discussed.


Asunto(s)
Alquenos/síntesis química , Catepsinas/antagonistas & inhibidores , Catepsinas/química , Inhibidores Enzimáticos/síntesis química , Urea/síntesis química , Compuestos de Vinilo/síntesis química , Alquenos/química , Calorimetría/métodos , Catálisis , Ciclización , Inhibidores Enzimáticos/farmacología , Indicadores y Reactivos/química , Modelos Moleculares , Estructura Molecular , Paladio/química , Rodio/química , Estereoisomerismo , Urea/química , Compuestos de Vinilo/química
12.
Org Lett ; 21(18): 7356-7360, 2019 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-31464131

RESUMEN

A Suzuki-Miyaura cross-coupling of α-pyridinium esters and arylboroxines has been developed. Combined with formation of the pyridinium salts from amino acid derivatives, this method enables amino acid derivatives to be efficiently transformed into α-aryl esters and amides. Under the mild conditions, broad functional group tolerance on both the amino acid derivatives and the arylboroxine are observed, including protic functional groups. Mechanistic studies support an alkyl radical intermediate, similar to other cross-couplings of alkylpyridinium salts.


Asunto(s)
Aminoácidos/química , Piridinas/química , Amidas/síntesis química , Amidas/química , Compuestos de Boro/química , Desaminación , Ésteres/síntesis química , Ésteres/química , Estructura Molecular , Sales (Química)/química
13.
Med Phys ; 34(2): 464-70, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17388162

RESUMEN

Intensity modulated arc therapy (IMAT) is an intensity modulated radiation therapy delivery technique originally proposed as an alternative to tomotherapy. IMAT uses a series of overlapping arcs to deliver optimized intensity patterns from each beam direction. The full potential of IMAT has gone largely unrealized due in part to a lack of robust and commercially available inverse planning tools. To address this, we have implemented an IMAT arc-sequencing algorithm that translates optimized intensity maps into deliverable IMAT plans. The sequencing algorithm uses simulated annealing to simultaneously optimize the aperture shapes and weights throughout each arc. The sequencer enforces the delivery constraints while minimizing the discrepancies between the optimized and sequenced intensity maps. The performance of the algorithm has been tested for ten patient cases (3 prostate, 3 brain, 2 head-and-neck, 1 lung, and 1 pancreas). Seven coplanar IMAT plans were created using an average of 4.6 arcs and 685 monitor units. Additionally, three noncoplanar plans were created using an average of 16 arcs and 498 monitor units. The results demonstrate that the arc sequencer can provide efficient and highly conformal IMAT plans. An average sequencing time of approximately 20 min was observed.


Asunto(s)
Algoritmos , Modelos Biológicos , Radiometría/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia Asistida por Computador/métodos , Radioterapia Conformacional/métodos , Simulación por Computador , Humanos , Dosificación Radioterapéutica , Dispersión de Radiación
14.
Med Phys ; 34(1): 307-14, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17278516

RESUMEN

Using direct aperture optimization, we have developed an inverse planning approach that is capable of producing efficient intensity modulated radiotherapy (IMRT) treatment plans that can be delivered without a multileaf collimator. This "jaws-only" approach to IMRT uses a series of rectangular field shapes to achieve a high degree of intensity modulation from each beam direction. Direct aperture optimization is used to directly optimize the jaw positions and the relative weights assigned to each aperture. Because the constraints imposed by the jaws are incorporated into the optimization, the need for leaf sequencing is eliminated. Results are shown for five patient cases covering three treatment sites: pancreas, breast, and prostate. For these cases, between 15 and 20 jaws-only apertures were required per beam direction in order to obtain conformal IMRT treatment plans. Each plan was delivered to a phantom, and absolute and relative dose measurements were recorded. The typical treatment time to deliver these plans was 18 min. The jaws-only approach provides an additional IMRT delivery option for clinics without a multileaf collimator.


Asunto(s)
Algoritmos , Modelos Biológicos , Neoplasias/radioterapia , Radiometría/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia Conformacional/métodos , Simulación por Computador , Humanos , Especificidad de Órganos , Dosificación Radioterapéutica , Efectividad Biológica Relativa
16.
Am J Vet Res ; 67(10): 1687-95, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17014317

RESUMEN

OBJECTIVE: To evaluate the pharmacokinetic-pharmacodynamic parameters of enrofloxacin and a low dose of amikacin administered via regional IV limb perfusion (RILP) in standing horses. ANIMALS: 14 adult horses. PROCEDURES: Standing horses (7 horses/group) received either enrofloxacin (1.5 mg/kg) or amikacin (250 mg) via RILP (involving tourniquet application) in 1 forelimb. Samples of interstitial fluid (collected via implanted capillary ultrafiltration devices) from the bone marrow (BMIF) of the third metacarpal bone and overlying subcutaneous tissues (STIF), blood, and synovial fluid of the radiocarpal joint were collected prior to (time 0) and at intervals after tourniquet release for determination of drug concentrations. For pharmacokinetic-pharmacodynamic analyses, minimum inhibitory concentrations (MICs) of 16 microg/mL (amikacin) and 0.5 microg/mL (enrofloxacin) were applied. RESULTS: After RILP with enrofloxacin, 3 horses developed vasculitis. The highest synovial fluid concentrations of enrofloxacin and amikacin were detected at time 0; median values (range) were 13.22 microg/mL (0.254 to 167.9 microg/mL) and 26.2 microg/mL (5.78 to 50.0 microg/mL), respectively. Enrofloxacin concentrations exceeded MIC for approximately 24 hours in STIF and synovial fluid and for 36 hours in BMIF. After perfusion of amikacin, concentrations greater than the MIC were not detected in any samples. Effective therapeutic concentrations of enrofloxacin were attained in all samples. CONCLUSIONS AND CLINICAL RELEVANCE: In horses with orthopedic infections, RILP of enrofloxacin (1.5 mg/kg) should be considered as a treatment option. However, care must be taken during administration. A dose of amikacin > 250 mg is recommended to attain effective tissue concentrations via RILP in standing horses.


Asunto(s)
Amicacina/farmacocinética , Antibacterianos/farmacocinética , Fluoroquinolonas/farmacocinética , Caballos/metabolismo , Amicacina/administración & dosificación , Animales , Antibacterianos/administración & dosificación , Área Bajo la Curva , Médula Ósea/metabolismo , Enrofloxacina , Miembro Anterior , Pruebas de Sensibilidad Microbiana , Distribución Aleatoria , Líquido Sinovial/metabolismo , Distribución Tisular
17.
J Am Vet Med Assoc ; 229(12): 1940-4, 2006 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-17173534

RESUMEN

OBJECTIVE: To determine the amount of time required for surface temperatures of thoracic and pelvic limbs in horses to return to pre-exercise temperatures after high-speed treadmill exercise, as detected via infrared thermographic imaging. DESIGN: Prospective study. ANIMALS: 6 Thoroughbreds. PROCEDURES: All horses had been trained on and conditioned to use of a high-speed treadmill. Baseline thermographic images were obtained 3 days prior to exercise (baseline). Horses were exercised on a treadmill at a walk for 5 minutes, a slow trot (3 m/s) for 5 minutes, a trot (5 to 6 m/s) for 5 minutes, and a slow gallop (6 to 8 m/s) for 5 minutes, then back to a trot for 3 minutes, a slow trot for 3 minutes, and a walk for 3 minutes prior to stopping. Thermal images were obtained immediately after stopping exercise (0 minutes) and 5, 15, 45, and 60 minutes and 6 hours after stopping exercise. Ambient temperature surrounding each horse was recorded. RESULTS: In all regions, significant differences in surface temperatures were detected between thermograms obtained before exercise and those obtained immediately after, 5 minutes after, and 15 minutes after exercise was stopped. There were no significant differences in surface temperatures between thermograms obtained before exercise and those obtained > or = 45 minutes after exercise was stopped. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, images generated via infrared thermography are not influenced by exercise-generated heat > or = 45 minutes after exercise is stopped.


Asunto(s)
Temperatura Corporal/fisiología , Caballos/fisiología , Condicionamiento Físico Animal/fisiología , Termografía/veterinaria , Animales , Regulación de la Temperatura Corporal/fisiología , Femenino , Masculino , Estudios Prospectivos , Termografía/métodos , Factores de Tiempo
18.
Vet Clin North Am Equine Pract ; 22(2): 363-88, viii, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16882480

RESUMEN

Infectious diseases of synovial and hoof structures in horses can be devastating to soundness and can result in life-threatening complications. Timely diagnosis and early aggressive treatment can result in successful outcomes and resumption of athletic careers; however, delays in recognition and therapy can be the most costly reasons for failure. Sterilization of affected compartments and tissues requires removal of microorganisms and compromised tissue. Debridement, lavage, and appropriate antimicrobial drug use are the most reliable avenues of treatment. Antimicrobial drugs can be administered by local, regional, and systemic routes. Lavage techniques and debridement typically require surgical manipulations.


Asunto(s)
Antiinfecciosos/administración & dosificación , Artritis Infecciosa/veterinaria , Pezuñas y Garras/microbiología , Enfermedades de los Caballos/terapia , Tenosinovitis/veterinaria , Animales , Antiinfecciosos/uso terapéutico , Artritis Infecciosa/diagnóstico , Artritis Infecciosa/terapia , Implantes de Medicamentos , Pezuñas y Garras/lesiones , Enfermedades de los Caballos/diagnóstico , Enfermedades de los Caballos/microbiología , Caballos , Inyecciones Intraarticulares/veterinaria , Perfusión/veterinaria , Rehabilitación/métodos , Tenosinovitis/diagnóstico , Tenosinovitis/terapia , Irrigación Terapéutica/veterinaria , Heridas y Lesiones/terapia , Heridas y Lesiones/veterinaria
19.
Phys Med Biol ; 50(23): 5653-63, 2005 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-16306659

RESUMEN

We have examined the degree to which step-and-shoot IMRT treatment plans can be simplified (using a small number of apertures) without sacrificing the dosimetric quality of the plans. A key element of this study was the use of direct aperture optimization (DAO), an inverse planning technique where all of the multi-leaf collimator constraints are incorporated into the optimization. For seven cases (1 phantom, 1 prostate, 3 head-and-neck and 2 lung), DAO was used to perform a series of optimizations where the number of apertures per beam direction varied from 1 to 15. In this work, we attempt to provide general guidelines for how many apertures per beam direction are sufficient for various clinical cases using DAO. Analysis of the optimized treatment plans reveals that for most cases, only modest improvements in the objective function and the corresponding DVHs are seen beyond 5 apertures per beam direction. However, for more complex cases, some dosimetric gain can be achieved by increasing the number of apertures per beam direction beyond 5. Even in these cases, however, only modest improvements are observed beyond 9 apertures per beam direction. In our clinical experience, 38 out of the first 40 patients treated using IMRT plans produced using DAO were treated with 9 or fewer apertures per beam direction. The results indicate that many step-and-shoot IMRT treatment plans delivered today are more complex than necessary and can be simplified without sacrificing plan quality.


Asunto(s)
Aceleradores de Partículas/instrumentación , Radioterapia de Intensidad Modulada/instrumentación , Radioterapia de Intensidad Modulada/métodos , Algoritmos , Simulación por Computador , Humanos , Neoplasias Pulmonares/radioterapia , Masculino , Fantasmas de Imagen , Neoplasias de la Próstata/radioterapia , Radiometría , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia Asistida por Computador , Programas Informáticos , Factores de Tiempo
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