Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
Int J Radiat Oncol Biol Phys ; 111(5): 1227-1236, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34418466

RESUMO

PURPOSE: Most new nasopharyngeal cancer cases occur in low-income and middle-income countries, and these patients experience poorer overall survival than that of new nasopharyngeal cancer cases in high-income countries. The goal of this research project is to determine whether the introduction of a radiation therapy quality assurance program can ultimately improve outcomes for nasopharyngeal cancer patients in lower-income and middle-income countries. This study reports the results of the first phase of the International Atomic Energy Agency Coordinated Research Project (325-E3-TM-47712). METHODS AND MATERIALS: This prospective study has 2 phases. Phase 1 is a survey of radiation therapy resources, patient characteristics and treatment, and results of radiation therapy quality assurance performed by the expert panel. An educational workshop reviewing phase 1 results for each center was completed before accrual of patients for phase 2. The ultimate aim of the study is to compare the first and second cohort of patients to see if quality assurance can result in fewer major protocol deviations and a 15% improvement in patients' 3-year progression-free survival. RESULTS: Of 14 participating centers, 13 (93%) had computed tomography simulators and linear accelerators (LINAC) with intensity modulated radiation therapy (IMRT) capacity, median 3 LINAC (range, 1-13), and median 10 radiation oncologists (range, 5-51). The annual number of nasopharyngeal cancer cases irradiated was median 54 (range, 10-627). Five of 14 centers (36%) had no local radiation therapy quality assurance. For the current phase 1 study, 134 patients were evaluated, 82.1% had MRI staging, 99.3% had metastatic workup, 65.6% undifferentiated histology, 51% stage 3 and 49% stage 4. Radiation therapy quality assurance revealed 81 (60.4%) of 134 patients had major protocol violations in gross tumor volume and high dose planning target volume contours and/or dosimetry, 28.4% patients had borderline plans, 15 (11.2%) acceptable, and only 6 (4.2%) had inevitable compromise due to tumor extent. CONCLUSIONS: This is the first International Atomic Energy Agency study to address the fundamental issue of treatment quality rather than altered treatment regimens. The high rate of unacceptable radiation therapy plans is a major concern, and we hope phase 2 will show a significant reduction and improved patient outcomes.


Assuntos
Neoplasias Nasofaríngeas , Energia Nuclear , Radioterapia de Intensidade Modulada , Países em Desenvolvimento , Humanos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/radioterapia , Estudos Prospectivos , Garantia da Qualidade dos Cuidados de Saúde , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
3.
Radiother Oncol ; 116(1): 15-20, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25913070

RESUMO

PURPOSE: To test the hypothesis that radiotherapy (RT) of head and neck squamous cell carcinoma (HNSCC) can be improved by hypoxic modification using nimorazole (NIM) in association with accelerated fractionation. MATERIALS AND METHODS: The protocol was activated in March 2012 as an international multicenter randomized trial in patients with HNSCC. Tumors were treated to a dose of 66-70Gy, 33-35 fractions, 6 fractions per week. NIM was administered in a dose of 1.2gperm(2), 90min before the first daily RT fraction. The primary endpoint was loco-regional failure. The trial was closed prematurely by June 2014 due to poor recruitment. An associated quality assurance program was performed to ensure the consistency of RT with the protocol guidelines. RESULTS: The trial was dimensioned to include 600 patients in 3years, but only 104 patients were randomized between March 2012 and May 2014 due to the inability to involve three major centers and the insufficient recruitment rate from the other participating centers. Twenty patients from two centers had to be excluded from the analysis due to the unavailability of the follow-up data. Among the remaining 84 patients, 82 patients were evaluable (39 and 43 patients in the RT+NIM and the RT-alone arms, respectively). The treatment compliance was good with only six patients not completing the full planned RT course, and 31 patients (79%) out of 39 allocated for NIM, achieving at least 90% of the prescribed drug dose. At the time of evaluation, 40 patients had failed to achieve persistent loco-regional tumor control, and a total of 45 patients had died. The use of NIM improved the loco-regional tumor control with an 18month post-randomization cumulative failure rate of 33% versus 51% in the control arm, yielding a risk difference of 18% (CI -3% to 39%; P=0.10). The corresponding values for overall death was 43% versus 62%, yielding a risk difference of 19% (CI -3% to 42%; P=0.10). Sixteen patients, out of 55 patients analyzed for hypoxic gene expression, were classified as having more hypoxic tumors. Such patients, if treated with RT alone, had a higher loco-regional tumor failure rate as compared to the rest of the patients with known hypoxic status (P=0.05). CONCLUSION: Although the trial was incomplete and suffered from a small number of patients, the results suggested an improvement in loco-regional tumor control and overall survival in patients with advanced HNSCC given the hypoxic modifier NIM in addition to accelerated fractionation RT. However, the trial also revealed that conducting multicenter and multinational study combining drug and RT in developing countries may suffer from uncontrolled and unsolvable problems.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeça e Pescoço/radioterapia , Nimorazol/uso terapêutico , Radiossensibilizantes/uso terapêutico , Adulto , Idoso , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Fracionamento da Dose de Radiação , Feminino , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Hipóxia/genética , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Cooperação do Paciente , Carcinoma de Células Escamosas de Cabeça e Pescoço
4.
AAPS PharmSciTech ; 11(3): 1115-8, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20623212

RESUMO

The purpose of this study was to resolve an anomalously high measure of extra-fine particle fraction (EPF) determined by the abbreviated cascade impactor possibly relevant for human respiratory tract (AIM-HRT) in the experiment described in Part 1 of this two-part series, in which the relative precision of abbreviated impactors was evaluated in comparison with a full resolution Andersen eight-stage cascade impactor (ACI). Evidence that the surface coating used to mitigate particle bounce was laterally displaced by the flow emerging from the jets of the lower stage was apparent upon microscopic examination of the associated collection plate of the AIM-HRT impactor whose cut point size defines EPF. A filter soaked in surfactant was floated on top of this collection plate, and further measurements were made using the same pressurized metered-dose inhaler-based formulation and following the same procedure as in Part 1. Measures of EPF, fine particle, and coarse particle fractions were comparable with those obtained with the ACI, indicating that the cause of the bias had been identified and removed. When working with abbreviated impactors, this precaution is advised whenever there is evidence that surface coating displacement has occurred, a task that can be readily accomplished by microscopic inspection of all collection plates after allowing the impactor to sample ambient air for a few minutes.


Assuntos
Aerossóis/química , Composição de Medicamentos/instrumentação , Inaladores de Pó Seco , Teste de Materiais/instrumentação , Medicamentos para o Sistema Respiratório/química , Tecnologia Farmacêutica/instrumentação , Administração por Inalação , Aerossóis/administração & dosagem , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Tamanho da Partícula , Medicamentos para o Sistema Respiratório/administração & dosagem
5.
AAPS PharmSciTech ; 11(2): 843-51, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20480271

RESUMO

The purpose of this study was to compare relative precision of two different abbreviated impactor measurement (AIM) systems and a traditional multi-stage cascade impactor (CI). The experimental design was chosen to provide separate estimates of variability for each impactor type. Full-resolution CIs are useful for characterizing the aerosol aerodynamic particle size distribution of orally inhaled products during development but are too cumbersome, time-consuming, and resource-intensive for other applications, such as routine quality control (QC). This article presents a proof-of-concept experiment, where two AIM systems configured to provide metrics pertinent to QC (QC-system) and human respiratory tract (HRT-system) were evaluated using a hydrofluoroalkane-albuterol pressurized metered dose inhaler. The Andersen eight-stage CI (ACI) served as the benchmark apparatus. The statistical design allowed estimation of precision with each CI configuration. Apart from one source of systematic error affecting extra-fine particle fraction from the HRT-system, no other bias was detected with either abbreviated system. The observed bias was shown to be caused by particle bounce following the displacement of surfactant by the shear force of the airflow diverging above the collection plate of the second impaction stage. A procedure was subsequently developed that eliminated this source of error, as described in the second article of this series (submitted to AAPS PharmSciTech). Measurements obtained with both abbreviated impactors were very similar in precision to the ACI for all measures of in vitro performance evaluated. Such abbreviated impactors can therefore be substituted for the ACI in certain situations, such as inhaler QC or add-on device testing.


Assuntos
Aerossóis/química , Teste de Materiais/instrumentação , Medicamentos para o Sistema Respiratório/química , Tecnologia Farmacêutica/instrumentação , Administração por Inalação , Aerossóis/administração & dosagem , Desenho de Equipamento , Inaladores Dosimetrados , Tamanho da Partícula , Pressão , Reprodutibilidade dos Testes , Medicamentos para o Sistema Respiratório/administração & dosagem
6.
Lancet Oncol ; 11(6): 553-60, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20382075

RESUMO

BACKGROUND: Several large randomised studies from western Europe and the USA have shown that accelerated fractionation of radiotherapy might be beneficial in the treatment of squamous-cell carcinoma of the head and neck (HNSCC). The aim of this study--the International Atomic Energy Agency (IAEA) ACC trial--was to determine whether accelerated fractionation could be applied in developing countries, where there are fewer therapeutic resources and where tumour burdens can be heavier. METHODS: Between Jan 6, 1999, to March 31, 2004, nine centres from Asia, Europe, the Middle East, Africa, and South America recruited patients with HNSCC of the larynx, pharynx, and oral cavity who were eligible for curative radiotherapy. Patients were randomly assigned in this open-label trial to receive an accelerated regimen of six fractions of radiotherapy per week (n=458) or to receive a conventional radiotherapy regimen of five fractions per week (n=450), receiving a total dose of 66-70 Gy in 33-35 fractions. Patients were stratified by tumour localisation, T classification, histopathological grade, and institution. Randomisation was done by a central computer-generated balanced randomisation algorithm. The primary endpoint was locoregional control, analysed for all eligible patients, irrespective of whether or not they had completed the course of radiotherapy. This trial is registered with ClinicalTrials.gov, number NCT00120211. FINDINGS: Six patients in the accelerated group and two in the conventional group were excluded from analyses because of withdrawal of consent or missing data. The planned total radiotherapy dose was received by 418 (92%) of the 452 eligible patients in the accelerated radiotherapy group and 413 (92%) of the 448 patients in the conventional radiotherapy group. Median treatment time was 40 days in the accelerated group and 47 days in the conventional group. The 5-year actuarial rate of locoregional control was 42% in the accelerated group versus 30% in the conventional group (hazard ratio [HR] 0.63, 95% CI 0.49-0.83; p=0.004). Acute morbidity in the form of confluent mucositis was noted in 45 patients in the accelerated group and 22 patients in the conventional group (2.15, 1.27-3.35); severe skin reactions were noted in 87 patients in the accelerated group and 50 patients in the conventional group (1.91, 1.31-2.79). There were no significant differences in late radiation side-effects. INTERPRETATION: An accelerated schedule of radiotherapy for HNSCC was more effective than conventional fractionation, and since it does not require additional resources, might be a suitable new worldwide standard baseline treatment for radiotherapy of HNSCC. FUNDING: International Atomic Energy Agency, Coordinated Research Project (IAEA-CRP E.3.30.18), the Danish Cancer Society, the Danish Strategic Research Council, and the Lundbeck Centre for Interventional Research in Radiation Oncology (CIRRO).


Assuntos
Carcinoma de Células Escamosas/radioterapia , Fracionamento da Dose de Radiação , Neoplasias de Cabeça e Pescoço/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/mortalidade , Intervalo Livre de Doença , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Lesões por Radiação , Dosagem Radioterapêutica , Taxa de Sobrevida , Adulto Jovem
7.
Respir Care ; 55(4): 419-26, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20406509

RESUMO

BACKGROUND: Delivery of bronchodilator to infants and small children from a pressurized metered-dose inhaler with valved holding chamber (pMDI-VHC) is limited by airway narrowness, short respiratory cycle time, and small tidal volume (V(T)). There is a need for a versatile, efficient VHC, given the variety of treatment modalities. METHODS: We tested the AeroChamber Mini VHC (the internal geometry of which is optimized for aerosol delivery, and which accepts a pMDI canister that has a dose counter) in experiments to determine differences in the delivery of hydrofluoroalkane-propelled albuterol (90 microg/actuation) during: mechanical ventilation via endotracheal tube (ETT); manual resuscitation via ETT; and spontaneous breathing via face mask. We tested 5 units of the AeroChamber Mini VHC per test. We simulated the tidal breathing of a premature neonate (V(T) 6 mL), a term neonate (V(T) 20 mL), and a child approximately 2 years old (V(T) 60 mL). We collected the aerosol on an electret filter and quantitatively assayed for albuterol. RESULTS: The total emitted mass of albuterol per actuation that exited the VHC was marginally greater during spontaneous breathing (12.1 +/- 1.8 microg) than during manual resuscitation (10.0 +/- 1.1 microg) (P = .046). Albuterol delivery via mechanical ventilation, though comparable with the premature-neonate model (3.3 +/- 1.2 microg), the term-neonate model (3.8 +/- 2.1 microg), and the 2-y-old-child model (4.2 +/- 2.3 microg) (P = .63), was significantly lower than in the spontaneous-breathing and manual-resuscitation models (P < .001). In the neonatal models the total emitted mass was similar with the spontaneous-breathing model (6.0 +/- 1.0 microg with the premature-neonate model, 10.5 +/- 0.7 microg with the term-neonate model) and the manual-resuscitation model (5.5 +/- 0.3 microg premature-neonate model, 10.7 +/- 0.9 microg term-neonate model) (P > or = .46 via one-way analysis of variance). CONCLUSION: The reduced delivery of albuterol during mechanical ventilation (compared to during spontaneous breathing and manual resuscitation via ETT) was probably associated with the saturated atmosphere in the breathing circuit (37 degrees C, relative humidity > 99%), compared to the ambient air (22 +/- 1 degrees C, 44 +/- 7% relative humidity). The AeroChamber Mini VHC may provide a versatile alternative to VHCs that are designed exclusively for one aerosol treatment modality.


Assuntos
Albuterol/administração & dosagem , Broncodilatadores/administração & dosagem , Pneumopatias Obstrutivas/tratamento farmacológico , Nebulizadores e Vaporizadores , Administração por Inalação , Aerossóis , Pré-Escolar , Desenho de Equipamento , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Intubação Intratraqueal , Máscaras , Modelos Biológicos , Reprodutibilidade dos Testes , Respiração Artificial
8.
Hum Fertil (Camb) ; 10(2): 123-7, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17564893

RESUMO

In the UK, the live birth rate after IVF in women aged less than 36 is >25%. The multiple birth rates in these women are excessive (20% to 25%). The perinatal mortality rate is increased significantly with IVF twins and triplets (8/1000 singletons, 20/1000 twins and 34/1000 triplets). Multiple pregnancies and births significantly increase the risks to the mother and the children, adversely affect family life and are economically disadvantageous to the couple and the wider community. The elective transfer of a single fresh embryo, followed if necessary by a single thawed embryo, in women at high risk of a multiple birth does not reduce the live birth rate and all but prevents the conception of twins and triplets.


Assuntos
Transferência Embrionária/estatística & dados numéricos , Prole de Múltiplos Nascimentos/estatística & dados numéricos , Resultado da Gravidez , Inglaterra/epidemiologia , Feminino , Humanos , Gravidez , Complicações na Gravidez/epidemiologia
9.
J Coll Physicians Surg Pak ; 16(12): 743-6, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17125630

RESUMO

OBJECTIVE: To determine the education of private drug sellers as an intervention tool in promoting rational use of medicines for diarrhoea at private drug outlets in a rural setting. PLACE AND DURATION OF STUDY: The study was conducted at Mithi, Tharparkar in rural Sindh in August 2005. PATIENTS AND METHODS: Diarrhea was selected to study drug-prescribing habit of private drug sellers. Evidence-based guidelines for control of diarrhea were developed along with simulation cases and keys. In phase-1, simulators were sent to 6 private drug sellers and their prescription was noted. After phase-1, 3 private drug sellers were educated about prescribing, while in the other 3, there was no intervention. In phase-2, simulators were sent again and prescriptions by private drug sellers was noted. RESULTS: The work experience of private drug sellers was between 5 to 15 years. Two private drug sellers were employed at each of the drug outlet with education between matriculation and graduation. All the private drug sellers prescribed medicines to customers with confidence. The private drug sellers prescribed medicines to customers on a daily basis that included all categories of medications. Amoebicidals, Anti-diarrheals, antispasmodics, antibiotics, analgesics and oral rehydration solutions were prescribed by 22(38.6%), 10(17.5%), 3(4.9%), 10(17.5%), 3(5.3%) and 9(15.8%) private drug sellers prior to intervention respectively. It changed to 0(0%), 6 (14%), 0(0%) 0 (0%), 4 (9.3%) and 16(37.2%) postintervention respectively. Referral to hospital for serious cases increased after intervention. CONCLUSION: The rational use of medicines can be promoted by providing education to private drug sellers. Further studies and education programs for private drug sellers are strongly recommended across the country.


Assuntos
Serviços Comunitários de Farmácia , Medicamentos sem Prescrição , Pessoal Técnico de Saúde/educação , Uso de Medicamentos , Humanos , Paquistão
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA