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2.
Adv Radiat Oncol ; 8(5): 101257, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37408670

RESUMO

Purpose: The global rise in cancer incidence has been accompanied by disproportionately high morbidity and mortality rates in low- and middle-income countries. Many patients who are offered potentially curative treatment for cervical cancer in low- and middle-income countries never return to start treatment for reasons that are poorly documented and little understood. We investigated the interplay of sociodemographic, financial, and geographic factors as barriers to care among such patients in Botswana and Zimbabwe. Methods and Materials: Patients seen in consultation between 2019 and 2021 who were >3 months late for an appointment to initiate definitive treatment were contacted via telephone and invited to complete a survey. Afterward, an intervention connected patients with resources and counseling to return for treatment. Follow-up data were collected 3 months later to ascertain the outcomes of the intervention. Fisher exact tests analyzed the relationship between the putative number and types of barriers and demographics. Results: We recruited 40 women who initially presented for oncology care but did not return for treatment at [Princess Marina Hospital] in Botswana (n = 20) and [Parirenyatwa General Hospital] in Zimbabwe (n = 20) to complete the survey. Overall, married women experienced more barriers than unmarried women (P < .001), and unemployed women were 10 times more likely to report a financial barrier than employed women (P = .02). In Zimbabwe, financial barriers and belief-associated barriers (eg, fear of treatment) were reported. In Botswana, many patients noted scheduling obstacles associated with administrative delays and COVID-19. At follow-up, 16 Botswana patients and 4 Zimbabwe patients had returned for treatment. Conclusions: Financial and belief barriers identified in Zimbabwe showcase the importance of targeting cost and health literacy to reduce apprehensions. In Botswana, administrative challenges could be addressed with patient navigation. Improving our understanding of the specific barriers to cancer care could enable us to help patients who might otherwise default.

4.
Radiother Oncol ; 151: 106-109, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32663536

RESUMO

Global Oncology capacity in Radiation Oncology (RO) needs development. We report on early outcomes of a Canadian Global Oncology elective scholarship program for trainees (2014-2019). The number of global oncology electives increased. Academic deliverables and collaborations were observed. There was evidence of personal and professional development.


Assuntos
Radioterapia (Especialidade) , Canadá , Bolsas de Estudo , Humanos
5.
JCO Glob Oncol ; 6: 919-928, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32603189

RESUMO

PURPOSE: For many oncology training programs in low- and middle-income countries, dedicated time for research education and mentorship of trainees is limited. Here, we report a 1-year-long collaboration between a cancer center in Canada and one in Ghana with the aim of imparting clinical research skills and mentoring the research of radiation oncology residents. METHODS: On the basis of a needs assessment conducted in Ghana, we designed a curriculum consisting of 13 weekly seminars delivered via videoconference, followed by a 1-year-long mentorship program to support research projects. The primary outcome was the feasibility of the program from seminars to manuscript preparation. We used multiple secondary outcomes to capture the learning experience with study-specific questionnaires. We evaluated critical thinking ability using the Berlin questionnaire. Funding was made available for research and travel to international conferences. RESULTS: Five Ghanaian trainees submitted research proposals. Nine Canadian faculty members delivered the seminars and two served as methodology mentors, and two Ghanaian faculty acted as local supervisors. Feedback questionnaires from all participants showed that they agreed strongly that they would recommend the sessions to another resident (75%), that the objectives were clear (71%), and that the topics were useful for their training (73%). At the end of the program, two Ghanaian trainees finalized their manuscripts and one was published. CONCLUSION: Here, we report on the implementation of a mentorship program focused on research methods and evidence-based medicine in sub-Saharan Africa. The program was successful in the drafting and publication of abstracts and manuscripts by local trainees.


Assuntos
Tutoria , Mentores , Canadá , Gana , Humanos , Pesquisadores
6.
Neurosurgery ; 86(4): 509-516, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31375826

RESUMO

BACKGROUND: The Gamma Knife (GK) Icon (Elekta AB) uses a cone-beam computed tomography (CBCT) scanner and an infrared camera system to support the delivery of frameless stereotactic radiosurgery (SRS). There are limited data on patients treated with frameless GK radiosurgery (GKRS). OBJECTIVE: To describe the early experience, process, technical details, and short-term outcomes with frameless GKRS at our institution. METHODS: We reviewed our patient selection and described the workflow in detail, including image acquisition, treatment planning, mask-based immobilization, stereotactic CBCT localization, registration, treatment, and intrafraction monitoring. Because of the short interval of follow-up, we provide crude rates of local control. RESULTS: Data from 100 patients are reported. Median age is 67 yr old. 56 patients were treated definitively, 21 postoperatively, and 23 had salvage GKRS for recurrence after surgery. Forty-two patients had brain metastases, 26 meningiomas, 16 vestibular schwannomas, 9 high-grade gliomas, and 7 other histologies. Median doses to metastases were 20 Gy in 1 fraction (range: 14-21), 24 Gy in 3 fractions (range: 19.5-27), and 25 Gy in 5 fractions (range: 25-30 Gy). Thirteen patients underwent repeat SRS to the same area. Median treatment time was 17.7 min (range: 5.8-61.7). We found an improvement in our workflow and a greater number of patients eligible for GKRS because of the ability to fractionate treatments. CONCLUSION: We report a large cohort of consecutive patients treated with frameless GKRS. We look forward to studies with longer follow-up to provide valuable data on clinical outcomes and to further our understanding of the radiobiology of hypofractionation in the brain.


Assuntos
Neoplasias Encefálicas/radioterapia , Radiocirurgia/instrumentação , Radiocirurgia/métodos , Idoso , Fracionamento da Dose de Radiação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
8.
Int J Radiat Oncol Biol Phys ; 100(5): 1246-1253, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29395628

RESUMO

PURPOSE: Most women with cervical cancer in Sub-Saharan Africa present with locally advanced disease. These women require external beam radiation therapy and brachytherapy for curative treatment, but data on their outcomes remain sparse. We report data on treatment characteristics, follow-up, toxicity, and cancer outcomes in a large population of patients from the National Centre for Radiotherapy in Accra, Ghana. METHODS AND MATERIALS: The charts of patients treated from 2006 to 2011 were reviewed. Patients treated without brachytherapy or with palliative intent were excluded. Staging computed tomography scans were not routinely performed. Cobalt 60 external beam radiation therapy was followed by 2 low-dose-rate brachytherapy insertions. Concurrent weekly cisplatin was recommended. Because many patients experienced delays from diagnosis to treatment, we calculated overall survival and locoregional recurrence from the date of first radiation therapy to the event date-or last follow-up when no event recurred-using the Kaplan-Meier (product-limit) method. RESULTS: We included 250 patients with a median age at diagnosis of 55 years. The International Federation of Gynecology and Obstetrics stage was IIB or lower in 63% of patients. The median dose to point A was 83 Gy (range, 60-97.5 Gy). The median doses to the bladder and rectal points were 71 Gy and 65 Gy, respectively. Of the patients, 69% received ≥4 cycles of concurrent cisplatin. The median overall treatment time was 73 days. The median follow-up period was 2.4 years, with 3-year overall survival and locoregional recurrence rates of 86% and 19%, respectively. The most commonly reported late side effect was vaginal stenosis and shortening, occurring in 32% of patients. We also identified nearly 300 patients who were offered curative treatment but never returned to start treatment. CONCLUSIONS: We report promising outcomes in a population of women with cervical cancer treated with concurrent chemoradiation therapy and brachytherapy in Ghana. To our knowledge, this is the largest series of its kind, and it demonstrates what can be achieved with a well-established cancer program in Sub-Saharan Africa.


Assuntos
Adenocarcinoma/radioterapia , Braquiterapia/métodos , Carcinoma Adenoescamoso/radioterapia , Carcinoma de Células Escamosas/radioterapia , Radioisótopos de Cobalto/uso terapêutico , Neoplasias do Colo do Útero/radioterapia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Adulto , Idoso , Carcinoma Adenoescamoso/tratamento farmacológico , Carcinoma Adenoescamoso/patologia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Quimiorradioterapia , Feminino , Gana , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/patologia
9.
Support Care Cancer ; 25(3): 719-727, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27815711

RESUMO

PURPOSE: We aim to identify the risk factors for a "rocky" treatment course (RTC) in head and neck cancer. METHODS: A retrospective case-control study was conducted utilizing data from a prospective study. We defined the RTC as a composite of adverse outcomes including G-tube dependence and increased nursing interventions. Statistically associative variables were included in a multivariable logistic regression. We also evaluated whether the RTC, or its components, associated with worse cancer outcomes. RESULTS: Being single, unemployed, having N2/3 disease and receiving chemoradiotherapy were associated with a RTC. In turn, G-tube dependence was associated with worse 3-year OS (73 vs 91 %; p = 0.02) and increased nursing interventions with worse 3-year locoregional recurrence-free survival (LRFS) (85 vs 92 %; p = 0.03) and locoregional recurrence (LRR) (14 vs 7 %; p = 0.03). CONCLUSIONS: We identified baseline factors associated with a RTC for head and neck cancer patients. Future supportive care interventions could be evaluated using the RTC as a marker of benefit.


Assuntos
Carcinoma de Células Escamosas/terapia , Neoplasias de Cabeça e Pescoço/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/diagnóstico , Estudos de Casos e Controles , Quimiorradioterapia , Intervalo Livre de Doença , Feminino , Neoplasias de Cabeça e Pescoço/diagnóstico , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Esvaziamento Cervical , Recidiva Local de Neoplasia/terapia , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco , Carcinoma de Células Escamosas de Cabeça e Pescoço , Resultado do Tratamento , Adulto Jovem
10.
Radiother Oncol ; 110(1): 61-70, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24094630

RESUMO

The purpose of this review was to determine the efficacy of re-irradiation in patients with bone metastases. A literature search was conducted in Ovid Medline, OldMedline, Embase, Embase Classic, and Cochrane Central Register of Controlled Trials using relevant subject headings and keywords such as bone metastases, radiotherapy and palliative care. The resulting articles were sorted for inclusion for palliative external beam radiation retreatment response rate data. The literature search produced 2164 references and 15 articles were included in the final selection. Complete, partial and overall response rates were calculated to be 20%, 50% and 68%, respectively. Information on treatment toxicities was scarce. The efficacy of re-irradiation is comparable to initial radiation treatment. However, aspects of re-irradiation treatment including dose fractionation, related adverse events and toxicities require further corroboration.


Assuntos
Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/secundário , Cuidados Paliativos/métodos , Neoplasias Ósseas/complicações , Fracionamento da Dose de Radiação , Humanos , Dor/etiologia , Dor/radioterapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Retratamento
11.
Int J Radiat Oncol Biol Phys ; 87(5): 1058-63, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24113057

RESUMO

PURPOSE: Conventional radiation therapy (RT) administered in 25 fractions after breast-conserving surgery (BCS) is the standard treatment for ductal carcinoma in situ (DCIS) of the breast. Although accelerated hypofractionated regimens in 16 fractions have been shown to be equivalent to conventional RT for invasive breast cancer, few studies have reported results of using hypofractionated RT in DCIS. METHODS AND MATERIALS: In this multicenter collaborative effort, we retrospectively reviewed the records of all women with DCIS at 3 institutions treated with BCS followed by hypofractionated whole-breast RT (WBRT) delivered in 16 fractions. RESULTS: Between 2003 and 2010, 440 patients with DCIS underwent BCS followed by hypofractionated WBRT in 16 fractions for a total dose of 42.5 Gy (2.66 Gy per fraction). Boost RT to the surgical bed was given to 125 patients (28%) at a median dose of 10 Gy in 4 fractions (2.5 Gy per fraction). After a median follow-up time of 4.4 years, 14 patients had an ipsilateral local relapse, resulting in a local recurrence-free survival of 97% at 5 years. Positive surgical margins, high nuclear grade, age less than 50 years, and a premenopausal status were all statistically associated with an increased occurrence of local recurrence. Tumor hormone receptor status, use of adjuvant hormonal therapy, and administration of additional boost RT did not have an impact on local control in our cohort. On multivariate analysis, positive margins, premenopausal status, and nuclear grade 3 tumors had a statistically significant worse local control rate. CONCLUSIONS: Hypofractionated RT using 42.5 Gy in 16 fractions provides excellent local control for patients with DCIS undergoing BCS.


Assuntos
Neoplasias da Mama/radioterapia , Carcinoma Intraductal não Infiltrante/radioterapia , Fatores Etários , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/mortalidade , Carcinoma Intraductal não Infiltrante/patologia , Carcinoma Intraductal não Infiltrante/cirurgia , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Feminino , Humanos , Mastectomia Segmentar , Pessoa de Meia-Idade , Análise Multivariada , Gradação de Tumores , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Neoplasia Residual , Segunda Neoplasia Primária/mortalidade , Segunda Neoplasia Primária/patologia , Pré-Menopausa , Quebeque , Retratamento/métodos , Estudos Retrospectivos , Medição de Risco , Resultado do Tratamento
12.
Radiat Oncol ; 8: 251, 2013 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-24165756

RESUMO

Mucoepidermoid carcinoma of the maxillary sinus is a rare malignancy of the head and neck. The location of this tumour near vital structures and its large size at presentation makes surgical resection with negative margins challenging. In incurable cases, relief from symptoms such as epistaxis may be achieved with radiation therapy. We present a case of mucoepidermoid carcinoma of the maxillary sinus that was effectively palliated with a short course of radiation therapy, achieving complete cessation of bleeding, decrease in tumour size, and long term control. We surveyed the literature on mucoepidermoid carcinomas and propose that some tumours may be particularly radiosensitive, benefiting from even short courses of radiation therapy.


Assuntos
Carcinoma Mucoepidermoide/radioterapia , Seio Maxilar/patologia , Radioterapia/métodos , Idoso de 80 Anos ou mais , Feminino , Hemorragia , Humanos , Cuidados Paliativos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento
13.
Phys Rev E Stat Nonlin Soft Matter Phys ; 85(4 Pt 2): 046210, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22680559

RESUMO

Biological systems contain biochemical control networks that reside within a remarkable spatial structure. We present a theoretical study of a biological system in which two chemically coupled species, an activating species and an inhibiting species forming a negative feedback, are synthesized at unique sites and interact with each other through diffusion. The dynamical behaviors in these systems depend on the spatial locations of these synthetic sites. In a negative feedback system with two sites, we find two dynamical modes: fixed point and stable oscillations whose frequency can be tuned by varying the distance between the sites. When there are multiple synthetic sites, we find more diverse dynamics, including chaos, quasiperiodicity, and bistability. Based on this theoretical analysis, it should be possible to create in the laboratory synthetic circuits displaying these dynamics. This study illustrates the concept of "spatial switching," in which bifurcations in the dynamics occur as a function of the geometry of the system.


Assuntos
Oscilometria/métodos , Algoritmos , Biofísica/métodos , Comunicação Celular , Comunicação , Simulação por Computador , Difusão , Modelos Biológicos , Modelos Estatísticos , Modelos Teóricos , Dinâmica não Linear , Física/métodos , Pseudomonas aeruginosa/metabolismo , Biologia de Sistemas , Teoria de Sistemas , Fatores de Tempo
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