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1.
Oper Dent ; 49(2): 119-126, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38349853

RESUMO

When restoring anterior teeth using resin composites, the use of silicone guide matrices obtained from diagnostic wax-ups is recommended, as this technique facilitates layering and optimizes working time. This is particularly important in polychromatic layering and when more than one anterior tooth is to be restored with resin composites. However, in cases of fractured anterior teeth, it is often not feasible to perform a previous impression and waxing. In these cases, due to trauma and related psychological aspects, patients usually seek immediate esthetic solutions. Therefore, an interesting restorative approach that can simplify the restorative technique is the creation of a silicone guide matrix obtained from the patient's fractured tooth, without the need for prior waxing. This type of personalized matrix was initially proposed by Bertholdo, Ricci, and Barrote. Thus, the purpose of the present work is to demonstrate a modification of the technique for making this type of custom-made matrix for the restoration of two upper central incisors of a 14-year-old patient who fractured his teeth in a bicycle accident.


Assuntos
Restauração Dentária Permanente , Fraturas dos Dentes , Humanos , Adolescente , Restauração Dentária Permanente/métodos , Resinas Compostas/uso terapêutico , Fraturas dos Dentes/terapia , Incisivo/lesões , Assistência Odontológica
2.
Clin Oncol (R Coll Radiol) ; 33(12): e511-e520, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34140206

RESUMO

AIMS: We describe the absolute and per capita numbers of megavoltage radiotherapy machines (MVMs) in Western Africa from 1969 to 2019. MATERIALS AND METHODS: Western Africa was defined in accordance with the United Nations' delineation and inclusive of 16 countries. A literature search for publications detailing the number of cobalt-60 machines (COs) and linear accelerators (LINACs) in radiotherapy centres was carried out. Population data from the World Bank Group and crude cancer rates from the International Agency for Research on Cancer were used to calculate ratios of million persons per MVM and MVMs per 1000 cancer cases. RESULTS: The numbers of MVMs in Western Africa in 1969, 1979, 1989, 1999 and 2009 were zero, two, three, six and nine, respectively. In 2019 there were 22 MVMs distributed across Ghana (five), Côte d'Ivoire (two), Mali (one), Mauritania (two), Nigeria (nine) and Senegal (three). Nine countries (56.3%) had no history of external beam radiotherapy (EBRT). The largest increase in absolute EBRT capacity occurred from 2017 to 2019, during which 13 MVMs were commissioned. The largest decrease in EBRT capacity occurred from 2015 to 2017, during which four LINACs and three COs were rendered non-operational. The ratio of million persons per MVM improved from 67.0 in 1979 to 17.8 in 2019. As of 2019, there was 0.09 MVM per 1000 cancer cases. CONCLUSIONS: Western African nations have experienced an increase in the absolute number of MVMs and per capita radiotherapy capacity during the last 50 years, especially in the last decade. As non-functional LINACs contributed to a temporary decline in the EBRT infrastructure, dual use of CO/LINAC technologies may act to promote the availability of EBRT treatment in centres with capacity for multiple MVMs.


Assuntos
Radioterapia (Especialidade) , Côte d'Ivoire , Humanos , Nigéria , Aceleradores de Partículas , Senegal
3.
Clin Oncol (R Coll Radiol) ; 33(4): e211-e220, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33250288

RESUMO

AIMS: Childhood cancer survival is suboptimal in most low- and middle-income countries (LMICs). Radiotherapy plays a significant role in the standard care of many patients. To assess the current status of paediatric radiotherapy, the International Atomic Energy Agency (IAEA) undertook a global survey and a review of practice in eight leading treatment centres in middle-income countries (MICs) under Coordinated Research Project E3.30.31; 'Paediatric radiation oncology practice in low and middle income countries: a patterns-of-care study by the International Atomic Energy Agency.' MATERIALS AND METHODS: A survey of paediatric radiotherapy practices was distributed to 189 centres worldwide. Eight leading radiotherapy centres in MICs treating a significant number of children were selected and developed a database of individual patients treated in their centres comprising 46 variables related to radiotherapy technique. RESULTS: Data were received from 134 radiotherapy centres in 42 countries. The percentage of children treated with curative intent fell sequentially from high-income countries (HICs; 82%) to low-income countries (53%). Increasing deficiencies were identified in diagnostic imaging, radiation staff numbers, radiotherapy technology and supportive care. More than 92.3% of centres in HICs practice multidisciplinary tumour board decision making, whereas only 65.5% of centres in LMICs use this process. Clinical guidelines were used in most centres. Practice in the eight specialist centres in MICs approximated more closely to that in HICs, but only 52% of patients were treated according to national/international protocols whereas institution-based protocols were used in 41%. CONCLUSIONS: Quality levels in paediatric radiotherapy differ among countries but also between centres within countries. In many LMICs, resources are scarce, coordination with paediatric oncology is poor or non-existent and access to supportive care is limited. Multidisciplinary treatment planning enhances care and development may represent an area where external partners can help. Commitment to the use of protocols is evident, but current international guidelines may lack relevance; the development of resources that reflect the capacity and needs of LMICs is required. In some LMICs, there are already leading centres experienced in paediatric radiotherapy where patient care approximates to that in HICs. These centres have the potential to drive improvements in service, training, mentorship and research in their regions and ultimately to improve the care and outcomes for paediatric cancer patients.


Assuntos
Neoplasias , Energia Nuclear , Radioterapia (Especialidade) , Criança , Países em Desenvolvimento , Humanos , Agências Internacionais , Oncologia , Neoplasias/radioterapia
4.
Clin Oncol (R Coll Radiol) ; 31(8): 529-538, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31229379

RESUMO

Despite the advances in the primary prevention of cervical cancer, there is an absolute increase in the incidence of cervical cancer as a result of an increase in world population. A vast majority of patients in low and low-middle income countries continue to present at a locally advanced stage, necessitating treatment with chemoradiation and brachytherapy. There is a dearth of equipment and trained professionals for the treatment of cervical cancer, especially in low and low-middle income countries. There is an urgent need to improve treatment availability and develop better treatments. Worldwide trends, however, reveal a low number of therapeutic and innovative research trials in cervical cancer. The present article elucidates the existing challenges and provides solutions to improve outcomes. The proposed strategies hinge on strengthening collaborations for global advocacy.


Assuntos
Carga Global da Doença/métodos , Neoplasias do Colo do Útero/epidemiologia , Feminino , Humanos , Neoplasias do Colo do Útero/patologia
5.
Clin Oncol (R Coll Radiol) ; 29(2): 84-92, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27939337

RESUMO

Recent years have seen various reviews on the lack of access to radiotherapy often based on geographic regions of the world such as Africa, Asia Pacific, Europe, Latin America and North America. Countries are often defined by their national income per capita levels based on World Bank definitions of high income, upper middle income, lower middle income and low income. Within the world regions, there are significant variations in gross national income (GNI) per capita among the different countries, and even within similar income levels, large variations exist. This report presents the actual status of radiotherapy and analyses the current needs and costs to provide full access in the different regions of the world. Actual coverage of the needs ranges from 34% in Africa to over 92% in Europe to about double the needs in North America. In line with this, proportional additional investments and operational costs are as high as more than 200% in Africa to almost none in North America. Two world regions face substantial challenges: Africa, based on the important demands to build new capacity and subsequently to maintain operational capability; and Asia Pacific, due to its high population density, translating into large absolute needs in radiotherapy treatments and resources, and hence in associated costs. With the data highlighting a large variability of GNI/capita even within similar income levels in the various world regions, it is expected that additional investment in resources and costs may be more dependent on income level of the country than on the GNI group or the geographic region of the world.


Assuntos
Países em Desenvolvimento , Necessidades e Demandas de Serviços de Saúde , Radioterapia/estatística & dados numéricos , África , Ásia , Europa (Continente) , Necessidades e Demandas de Serviços de Saúde/economia , Humanos , Renda , Radioterapia/economia , Classe Social
6.
Clin Oncol (R Coll Radiol) ; 27(2): 107-14, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25455407

RESUMO

About 57% of the total number of cancer cases occur in low and middle income countries. Radiotherapy is one of the main components of cancer treatment and requires substantial initial investment in infrastructure and training. Many departments continue to have basic facilities and to use simple techniques, while modern technologies have only been installed in big cities in upper-middle income countries. More than 50% of cancer patients requiring radiotherapy in low and middle income countries lack access to treatment. The situation is dramatic in low income countries, where the proportion is higher than 90%. The overall number of additional teletherapy units needed corresponds to about twice the installed capacity in Europe. The figures for different income level groups clearly show the correlation between gross national income per capita and the availability of services. The range of radiotherapy needs currently covered varies from 0% and 3-4% in low income countries in Latin America and Africa up to 59-79% in upper-middle income countries in Europe and Central Asia. The number of additional radiation oncologists, medical physicist, dosimetrists and radiation therapists (RTTs) required to operate additional radiotherapy departments needed is 43 200 professionals. Training and education programmes are not available in every developing country and in many cases the only option is sending trainees abroad, which is not a cost-effective solution. The implementation of adequate local training should be the following step after establishing the first radiotherapy facility in any country. Joint efforts should be made to establish at least one radiotherapy facility in countries where they do not exist, in order to create radiotherapy communities that could be the base for future expansion.


Assuntos
Necessidades e Demandas de Serviços de Saúde , Neoplasias/radioterapia , Países em Desenvolvimento , Humanos , Neoplasias/economia , Neoplasias/epidemiologia , Radioterapia/economia
7.
Int J Radiat Oncol Biol Phys ; 31(4): 765-75, 1995 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-7860387

RESUMO

PURPOSE: This study retrospectively assesses the patterns of failure in conservatively treated early stage breast cancer patients by correlating various clinical, pathologic, and treated-related factors with local, axillary, and distant relapse. METHODS AND MATERIALS: Between 1973 and 1990, 796 patients (817 breasts) received breast conservation surgery followed by radiotherapy. Local recurrences were counted as events even if they occurred simultaneously or after the appearance of axillary or distant metastases. RESULTS: The 10-year actuarial relative disease-free survival (DFS) rate for T1N0, T2N0, and T1-2N1 was 82%, 71%, and 54%, respectively. Stage N0 patients had a significant DFS advantage over N1 patients (p = 0.02). The 15-year actuarial local recurrence-free rate for T1 and T2 tumors was 82% and 87%, respectively (p = nonsignificant). Univariate analysis identified three significant risk factors for local relapse: (a) 48 breasts with tumors showing an extensive intraductal component had a crude local recurrence rate of 23% compared to 8% for 769 breasts without intraductal component (p = 0.0016); (b) the actuarial 10-year local recurrence-free rate for patients under age 40 years was 64% compared to 88% for patients over 40 years (p < 0.0001); (c) the 10-year actuarial local recurrence-free rate for 416 postmenopausal women without adjuvant tamoxifen was 83% compared to 97% for 107 postmenopausal women with tamoxifen (p = 0.0479). Salvage therapy for operable local recurrent patients resulted in a 8-year actuarial DFS rate of 47%, significantly lower than that obtained with primary treatment. The incidence of axillary relapse as the first sign of recurrence was 2%, and could be correlated with the lack of axillary dissection (p < 0.0000005) and primary tumor size (p = 0.03). Radiotherapy to the axilla did not influence axillary relapse. Actuarial 5-year DFS rate after treatment of isolated axillary recurrence was 27%. Axillary failure was a marker for distant failure. Contralateral breast cancer occurred in 8% of patients and did not have a detrimental effect on survival. Adjuvant tamoxifen decreased the 9-year actuarial incidence of contralateral breast cancer from 10% to 4% (p = 0.053). CONCLUSIONS: Tumors with extensive intraductal component, age under 40 years, and the omission of adjuvant tamoxifen in postmenopausal women increased local recurrence rate. Stage T2 and the lack of axillary dissection increased axillary recurrence rate. Stage N+ and local or axillary relapse increased distant failure rate. Axillary irradiation did not influence locoregional control nor survival. Improved therapy is needed for relapsing patients.


Assuntos
Neoplasias da Mama/cirurgia , Mama/cirurgia , Recidiva Local de Neoplasia , Análise Atuarial , Fatores Etários , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Intervalo Livre de Doença , Feminino , Humanos , Excisão de Linfonodo , Metástase Linfática , Recidiva Local de Neoplasia/epidemiologia , Estadiamento de Neoplasias , Pós-Menopausa , Dosagem Radioterapêutica , Estudos Retrospectivos , Fatores de Risco , Terapia de Salvação , Tamoxifeno/administração & dosagem , Falha de Tratamento
8.
Int J Radiat Oncol Biol Phys ; 35(5): 907-14, 1996 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-8751399

RESUMO

PURPOSE: To establish an optimum fractionation for medium dose rate (MDR) brachytherapy from retrospective data of patients treated with different MDR schedules in comparison with a low dose rate (LDR) schedule. METHODS AND MATERIALS: The study population consists of consecutive Stage IB-IIA-IIB patients who received radiotherapy alone with full dose brachytherapy plus external beam pelvic and parametrial irradiation from 1986-1993. Patients also receiving surgery or chemotherapy were excluded. The LDR group (n = 102, median follow-up: 80 months) received a median dose to Point A of two 32.5 Gy fractions at 0.44 Gy/h plus 18 Gy of external whole pelvic irradiation. The MDR1 group (n = 30, median follow-up: 45 months) received a mean dose of two 32 Gy fractions at 1.68 Gy/h. An individual dose reduction of 12.5% was planned for this group according to the Manchester experience, but only a 4.8% dose reduction was achieved. The MDR2 group (n = 10, median follow-up: 36 months) received a dose of two 24 Gy fractions at 1.65 Gy/h. The MDR3 group (n = 10, median follow-up 33 months) received a mean dose of three 15.3 Gy fractions at 1.64 Gy/h. And finally, the MDR4 group (n = 38, median follow-up: 24 months) received six 7.7 Gy fractions from two pulses 6 h apart in each of three insertions at 1.61 Gy/h. The median external pelvic dose to MDR schedules was between 12 and 20 Gy. The linear quadratic (LQ) formula was used to calculate the biologically effective dose (BED) to tumor (Gy10) and rectum (Gy3), assuming T1/2 for repair = 1.5 h. RESULTS: The crude central recurrence rate was 6% for LDR (mean BED = 95.4 Gy10) and 10% for MDR4 (mean BED = 77.0 Gy10) (p = NS). The remaining MDR groups had no recurrences. Grade 2 and 3 rectal or bladder complications were 0% for LDR (rectal BED = 109 Gy3) 83% for MDR1 (BED = 206 Gy3), and 30% for MDR3 (BED = 127 Gy3). The MDR2 and MDR4 groups presented no complications (BED, 123 Gy3, and 105 Gy3, respectively). The LQ formula appears to correlate with late complications of the different MDR regimens. A BED above 125 Gy3 was associated with Grade 2 + 3 rectal complications. Adequate central tumor control may be compromised with a tumor BED below 90-95 Gy10. CONCLUSIONS: Medium dose rate brachytherapy at 1.6 Gy/h to Point A has a marked dose rate effect. Increased fractionation is the cost of overcoming the less favorable therapeutic ratio for MDR than for LDR. A larger (25%) reduction of brachytherapy dose than previously reported is also necessary. Our most recently developed schedule for Stage I-II patients is three insertions on three treatment days with six 8.0 Gy brachytherapy fractionations, two on each treatment day, following or preceding an external whole pelvis dose of 18 Gy, and followed by additional external parametrial dose.


Assuntos
Braquiterapia , Dosagem Radioterapêutica , Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/epidemiologia , Estadiamento de Neoplasias , Estudos Retrospectivos , Neoplasias do Colo do Útero/patologia
9.
Int J Radiat Oncol Biol Phys ; 43(5): 1061-4, 1999 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10192356

RESUMO

PURPOSE: To compare results and complications of our previous low-dose-rate (LDR) brachytherapy schedule for early-stage cancer of the cervix, with a prospectively designed medium-dose-rate (MDR) schedule, based on the linear-quadratic model (LQ). METHODS AND MATERIALS: A combination of brachytherapy, external beam pelvic and parametrial irradiation was used in 102 consecutive Stage Ib-IIb LDR treated patients (1986-1990) and 42 equally staged MDR treated patients (1994-1996). The planned MDR schedule consisted of three insertions on three treatment days with six 8-Gy brachytherapy fractions to Point A, two on each treatment day with an interfraction interval of 6 hours, plus 18 Gy external whole pelvic dose, and followed by additional parametrial irradiation. The calculated biologically effective dose (BED) for tumor was 90 Gy10 and for rectum below 125 Gy3. RESULTS: In practice the MDR brachytherapy schedule achieved a tumor BED of 86 Gy10 and a rectal BED of 101 Gy3. The latter was better than originally planned due to a reduction from 85% to 77% in the percentage of the mean dose to the rectum in relation to Point A. The mean overall treatment time was 10 days shorter for MDR in comparison with LDR. The 3-year actuarial central control for LDR and MDR was 97% and 98% (p = NS), respectively. The Grades 2 and 3 late complications (scale 0 to 3) were 1% and 2.4%, respectively for LDR (3-year) and MDR (2-year). CONCLUSIONS: LQ is a reliable tool for designing new schedules with altered fractionation and dose rates. The MDR schedule has proven to be an equivalent treatment schedule compared with LDR, with an additional advantage of having a shorter overall treatment time. The mean rectal BED Gy3 was lower than expected.


Assuntos
Braquiterapia/métodos , Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Modelos Lineares , Pessoa de Meia-Idade , Estudos Prospectivos , Dosagem Radioterapêutica , Neoplasias do Colo do Útero/mortalidade
10.
Int J Radiat Oncol Biol Phys ; 37(2): 343-50, 1997 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9069306

RESUMO

PURPOSE: This study assessed the effectiveness and toxicity of induction chemotherapy (CT) and radiation therapy (RT) in the treatment of locally advanced carcinoma of the cervix with data provided by a pilot study and a randomized trial. METHODS AND MATERIALS: Eighty-six patients with International Federation of Gynecology and Obstetrics (FIGO) Stage IB-IVA (Stage IB >4-cm tumor diameter) (Group A) were entered in a pilot study and treated with cisplatin (50 mg/m2), vincristine (1 mg/m2 on days 1, 11, and 21), bleomycin (25 mg/m2 infusion on days 1-3, 11-13, and 21-23), and standard RT. Ninety-six patients were randomized to either this same CT regimen and RT, or RT alone (Group B: CT plus RT or RT). RESULTS: In Group A, 58% responded to induction CT. With a mean follow-up of 78 months, 73% achieved pelvic control (LRC), and 55% were disease-free survivors. Response to CT was not a marker for ultimate LRC or increased disease-free survival (DFS). In Group B, 62% responded to CT. With a mean follow-up of 43 months, LRC was 68% and 65% for all randomized patients in the CT plus RT and RT arms, respectively (p = NS). In patients who completed treatment, 78% and 70%, respectively, achieved LRC (p = NS). Disease-free survival rates were 38% and 49% for randomized patients in the CT plus RT and RT arms (p = NS), respectively, and 44% and 52% in those patients completing treatment (p = NS), respectively. Complications were acceptable. CONCLUSION: Data from this study did not prove the efficacy of induction CT before definitive RT in locally advanced cancer of the cervix. Induction CT with the currently used combinations and modes of administration should not be considered standard therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Bleomicina/administração & dosagem , Cisplatino/administração & dosagem , Terapia Combinada , Intervalo Livre de Doença , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Projetos Piloto , Indução de Remissão , Neoplasias do Colo do Útero/patologia , Vincristina/administração & dosagem
11.
Radiother Oncol ; 47(2): 145-8, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9683361

RESUMO

Patients with head and neck cancer were randomized in a double-blind manner to receive 40 mg/day prednisone (n = 32) or placebo (n = 34). The prescribed daily tumour dose was 1.6 Gy twice daily with an interfraction interval of > or =6 h. Treatment interruptions were at the discretion of the radiation oncologists. The primary study end-point was the total duration of treatment. A mean 4.4 day reduction was observed in the total elapsed treatment duration for the prednisone arm, 34.3 versus 29.9 days (P = 0.013), which paralleled a significantly lower median total tumour and biologically effective dose (BED) Gy10 in this arm. A trend favouring shorter treatment interruptions in the prednisone arm was also found, but not a reduction in the intensity or duration of mucositis.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Glucocorticoides/uso terapêutico , Neoplasias de Cabeça e Pescoço/radioterapia , Mucosa/efeitos da radiação , Prednisona/uso terapêutico , Lesões por Radiação/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Fracionamento da Dose de Radiação , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica
14.
Radiat Oncol Investig ; 5(6): 289-99, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9436246

RESUMO

The amount of dose reduction on changing from low dose rate (LDR) brachytherapy to medium dose rate (MDR) or high dose rate (HDR) afterloading has been the subject of much debate. The magnitude of reduction depends, together with other possible factors, on two radiobiological parameters: the alpha/beta ratio and the half-time of repair of the relevant tissues. In an attempt to extract these radiobiological parameters for the late rectal complications observed in our previously published clinical results four different schedules using MDR and one using LDR are analyzed. The percentage incidence of complications was a function of increasing biologically effective dose (BED), but would yield nonsense scattergrams if plotted against raw total dose. In addition, for three other published MDR series, three LDR series, and two HDR series, the incidence of rectal complications is plotted against BED to examine the predictive potential of using BED as the surrogate of total dose. Our own results were published in 1996, consisting of 102 patients treated at the LDR of 0.44 Gy/hr and 88 patients treated by four different schedules using an MDR of 1.6-1.7 Gy/hr. Follow-up is at least 3 years in all schedules. The linear quadratic formula including the "g" dose rate factor was used to analyze them, assuming exponential repair of the repairable beta term. First, multivariate and profile likelihood analyses were carried out to obtain estimates of alpha/beta and T1/2 for rectal late responding tissues. Then graphs of incidence of rectal complications vs. BED were constructed, assuming alpha/beta = 3 Gy and T1/2 = 1.5 hr, values which had not been contradicted by the multivariate analysis. Graphs were drawn both for "all grades including mild reactions" (grades 1 + 2 + 3) and for "serious" complications (grade 3 in our system). In addition, other published cervical brachytherapy series were reviewed, with calculation of their BEDs if not published by the authors. It was necessary to review and compare their grading systems, so that "mild and moderate" (grades 1 and 2) could be contrasted with "serious" (grades 3 and 4 or 5 in various systems). Comparisons were made with other published results, including three LDR, three MDR, and two HDR series spanning from 1982 to 1997. The BEDs at which the incidence of rectal complications rose above the arbitrary level of 10% were compared for all three ranges of dose rate. The multivariate analysis gave estimates of alpha/beta and T1/2 which were not significantly different from 3 Gy and 1.5 hr, respectively, so these values were used to compute the BEDs for the subsequent comparisons. It was found that the graphs of incidence of rectal complications for "all grades including mild" agreed rather better between all series than might have been expected, within a provisional (10%) threshold BED of range 100-123 Gy3 (60-74 Gy given as 2 Gy fractionated external beam or as LDR). The dose-response curves diverged above these values, as expected until common grading systems such as SOMA/ LENT become more widely used. For "serious" complications the 10% incidence occurred at a median BED of 140 Gy3 (84 Gy given as 2 Gy fractionated external beam or as LDR), range 124-155 Gy3. The use of BED (or extrapolated response dose), assuming alpha/beta = 3 Gy and T1/2 = 1.5 hr, instead of total dose, enabled incidence of late rectal complications in cervical brachytherapy with LDR, MDR, and HDR to be plotted in a reasonably consistent way. This does not mean that those parameter values have been definitively determined, but they appear to be provisional values that may be of use in comparing the expected effects of new schedules until better values are obtained from greater use of common grading systems.


Assuntos
Braquiterapia/efeitos adversos , Lesões por Radiação/epidemiologia , Reto/efeitos da radiação , Neoplasias do Colo do Útero/radioterapia , Relação Dose-Resposta à Radiação , Feminino , Seguimentos , Humanos , Incidência , Funções Verossimilhança , Análise Multivariada , Estadiamento de Neoplasias , Prognóstico , Lesões por Radiação/patologia , Dosagem Radioterapêutica , Doenças Retais/epidemiologia , Neoplasias do Colo do Útero/patologia
15.
Head Neck ; 23(8): 661-8, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11443749

RESUMO

BACKGROUND AND PURPOSE: Optimal treatment duration of altered fractionation schedules in head and neck cancer is still undefined. A retrospective study on local tumor control, survival, and complications of accelerated hyperfractionated irradiation in head and neck cancer was undertaken to investigate whether there was an advantage in further shortening overall time from 6.5 weeks. METHODS: Four hundred nineteen consecutive male patients treated with radiation alone for cure 1987-1998 were analyzed. Patients with stage I, or treated also with brachytherapy implants or chemotherapy, were excluded. Treatment with accelerated hyperfractionation was performed twice daily, at a median of 1.6 Gy/fraction, to a total median dose of 68 Gy in 39 days. The patient population was divided into two groups: those with < or =39 days overall treatment time (group A, n = 227; median, 33 days) and those with >39 days (group B, n = 192; median, 46 days). Group A received a significant median tumor dose reduction of 7% compared with group B. RESULTS: The 7-year actuarial local control (LC) rates were 59% and 48% for groups A and B, respectively (p =.02). The actuarial LC rates for T1-2 patients were 79% and 74% at 7 years for groups A and B, respectively (p = NS). Similarly, for T3-4 patients, they were 47% and 35% (p =.02), respectively. The 7-year actuarial disease-free survival (DFS) rates for groups A and B were 39% and 26% (p =.01), respectively. For stage II patients, DFS was 62% and 60% at 7 years (p = NS) for groups A and B, respectively. And similarly, for stage III-IV patients, DFS was 33% and 20% (p =.04), respectively, at 7 years. LC and DFS rates at 7 years for T4 and stage IV patients, respectively, were significantly improved in group A. Cox regression analyses for LC showed that both T stage and overall time were significant prognostic factors. Similarly, UICC clinical stage and overall time were significant prognostic factors for DFS. There was no difference in acute morbidity between the two groups: 3% of patients in both groups required tube or parenteral feeding. The 7-year actuarial probability of RTOG/EORTC grades 3-5 late effects was 15% and 13%, respectively, for each group (p = NS). CONCLUSIONS: This study, with the limitations of a retrospective study, has shown a significant improvement in local tumor control and disease-free survival, in patients treated with shorter overall treatment times (median, 33 days) with an accelerated hyperfractionated irradiation schedule compared with those treated with a median duration of 46 days. No significant enhancement of acute reactions and late morbidity were observed with the shorter schedule.


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 , Neoplasias de Cabeça e Pescoço/mortalidade , Humanos , Tábuas de Vida , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
16.
Cancer ; 91(12): 2353-60, 2001 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11413525

RESUMO

BACKGROUND: The authors undertook a retrospective study on local tumor control, survival, and complications of conventional irradiation compared with accelerated hyperfractionated irradiation in women with selected head and neck tumor sites. METHODS: One hundred eight consecutive women who were treated with radiation alone for cure during 1974-1998 were analyzed. Patients were excluded who had T1 tumors of the vocal cord and those who were treated with brachytherapy implants. Fifty-nine patients were treated with conventional fractionation once daily (QD) during 1974-1998 with a median dose of 2.1 grays (Gy) per fraction up to a total median dose of 69 Gy in a median overall time of 54 days. Forty-nine patients were treated with accelerated hyperfractionation twice daily (BID) during 1987-1998 at a median dose of 1.6 Gy per fraction BID, with an interfraction interval of 4-6 hours, for a total median dose of 66 Gy in 35 days. Patients were not randomized into the QD group or the BID group. RESULTS: The 7-year actuarial local control (LC) rates for T1-T2 tumors in QD-treated and BID-treated patients were 79% and 87%, respectively (P = not significant [NS]). For T3-T4 tumors, the LC rates at 7 years were 59% and 56% for the QD and BID groups, respectively (P = NS). A Cox regression analysis for LC showed that the significant variables were T classification and overall time. Schedule (QD or BID), total dose, dose per fraction, and patient age were not significant variables. For the QD and BID groups, the 7-year actuarial cause specific survival rates for patients with Stage I-II disease were 100% and 65%, respectively (P = 0.004), and, for patients with Stages III-IVA,IVB disease, the rates were 39% and 56%, respectively (P = NS), respectively. Acute morbidity was higher with the BID schedule: In the BID group, 8% of patients required tube or parenteral feeding, and 0% of patients in the QD group required such feeding (P = 0.04). The 5-year actuarial probability of Grade 3-5 late effects (according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer grading system) was 4% for the BID group and 0% for the QD group (P = NS). CONCLUSIONS: This study suggests that accelerated hyperfractionated irradiation for women with advanced carcinoma of the head and neck does not provide significantly better local tumor control or cause specific disease free survival compared with conventional fractionation. Women with these malignancies appear to have a better prognosis compared with men.


Assuntos
Carcinoma/radioterapia , Fracionamento da Dose de Radiação , Neoplasias de Cabeça e Pescoço/radioterapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/mortalidade , Intervalo Livre de Doença , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
17.
Int J Cancer ; 90(2): 80-91, 2000 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-10814958

RESUMO

A retrospective study on local tumor control, survival, and complications of conventional irradiation vs. accelerated hyperfractionated irradiation in patients with selected head and neck cancer sites was undertaken. A total of 1,007 consecutive patients treated with radiation alone for cure from 1974-1997 were analyzed. Excluded were female patients, patients with T1 stage of the vocal cord, and patients also treated with brachytherapy implants. There were 637 patients treated with conventional fractionation once daily (QD) in 1974-1997, at a median 2.1 Gy/fraction, to a total median dose of 71.4 Gy in a median overall time of 54 days. As was common before the mid-1980s, 39% and 22% of patients had overall times exceeding 8 and 9 weeks, respectively; 370 patients were treated with accelerated hyperfractionation twice daily (BID) from 1987-1997, at a median of 1.6 Gy/fraction, with an interfraction interval of 4-6 h, to a total median dose of 68 Gy in 40 days. Both schedules were well-balanced with respect to their pretreatment characteristics. Patients were not randomized into QD or BID. The 10-year actuarial probability of local control was 37% vs. 56% for QD and BID, respectively (P < 0.001), which reflects an increase of 19% or a 51% reduction in the local failure rate. Multivariate analysis revealed that T-stage, QD or BID schedule, and overall treatment time were significant independent factors for achieving local tumor control. The 10-year actuarial probability of cause-specific disease-free survival was 25% and 30% for QD and BID, respectively (P = 0.012). Acute morbidity was slightly higher with the BID schedule: patients requiring tube or parenteral feeding were 2.4% for BID and 0.5% for QD (P = 0.01). The 10-year actuarial probability of RTOG/EORTC Grades 3-5 late effects was 13% for both QD and BID. The lack of increase in late complications was most probably due to the lower total dose and dose per fraction in the BID schedule. This study has shown that accelerated hyperfractionated irradiation using two doses of 1.6 Gy each treatment day for less than 6 weeks in advanced head and neck cancer in male patients provides significantly better local tumor control and cause-specific disease-free survival, without increased late morbidity, than conventional fractionation delivered at the previously relaxed overall times of 7 weeks, but sometimes exceeding 8 or 9 weeks. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 80-91, 2000.


Assuntos
Carcinoma de Células Escamosas/radioterapia , 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 , Morbidade , Análise Multivariada , Neoplasias Primárias Múltiplas/radioterapia , Radioterapia/efeitos adversos , Radioterapia/métodos , Estudos Retrospectivos , Taxa de Sobrevida
18.
Int J Gynecol Cancer ; 11(6): 445-53, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11906547

RESUMO

The objective of this study was to describe the results and complications of a prospectively designed high-dose-rate (HDR) brachytherapy schedule for early-stage cancer of the cervix, at 14 Gy/h to point A, based on the linear-quadratic model and our clinical experience. We used a combination of brachytherapy and external beam pelvic and parametrial irradiation in 88 consecutively seen patients with stage IB1-IIB treated by irradiation alone (1995-1998). The modeled HDR schedule consisted of three insertions on three treatment days separated by 10 days, with six 7 Gy planned brachytherapy fractions to point A, at 14 Gy/h, two on each treatment day with an interfraction interval of 6 h, plus an 18 Gy external whole-pelvic dose followed by additional parametrial irradiation. The calculated biologically effective dose (BED) was 92 Gy10 for tumor and 110 Gy3 for the rectum, equivalent to 77 and 66 Gy in 2 Gy fractions, respectively. The median overall treatment time was 41 days. The actuarial 4-year central recurrence-free rate, pelvic control, and disease-free survival rate were 97%, 93%, and 88% for stages IB-IIA and 79%, 75%, and 75% for stage IIB. The actuarial 4-year late complication rate for grades 2-3 was 4.7% (scale 0-3). We conclude that preliminary results of this HDR brachytherapy schedule for early-stage disease at a median follow-up of 52 months are as effective as the previously used low dose rate (LDR) at 0.44 Gy/h at point A. They are also as effective as medium-dose-rate schedules (MDR) at 1.6-1.5 Gy/h at this institution and do not require a further increase in fractionation of intracavitary treatments or in the whole-pelvic external beam irradiation dose common to standard HDR schedules. In addition, more patients per machine can be treated per day compared with MDR. Longer follow-up is required for a complete assessment of late complications.


Assuntos
Adenocarcinoma/radioterapia , Braquiterapia/métodos , Carcinoma de Células Escamosas/radioterapia , Radioisótopos de Césio/uso terapêutico , Neoplasias do Colo do Útero/radioterapia , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Intervalo Livre de Doença , Relação Dose-Resposta à Radiação , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Estudos Prospectivos , Dosagem Radioterapêutica , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/patologia
19.
Aten Primaria ; 25(2): 103-6, 2000 Feb 15.
Artigo em Espanhol | MEDLINE | ID: mdl-10736940

RESUMO

OBJECTIVES: To find the prevalence of vaginal candidiasis in pregnant women monitored through primary care and to see whether it is on the increase. DESIGN: Descriptive and retrospective study of pregnant women. SETTING: Cazoña Health District (34,783 inhabitants). SUBJECTS: The entire obstetric population monitored by our health centre between 1992 and 1997 inclusive. MEASUREMENTS AND RESULTS: Retrospective study of clinical histories of all the pregnant women seen at our health centre (878 pregnancies). After discounting those referred to obstetricians, abortions/miscarriages and premature births, 549 normal low-risk pregnancies (62.30% of the total) were monitored to completion in primary care. The women's age range was 16 to 40. The mean prevalence of candidiasis was 18% (CI, 15.0-21.6). Its frequency increased as the number of pregnancies increased and dropped as the age of the pregnant women increased. CONCLUSIONS: Prevalence found in our study was 18% and did not increase as the years passed.


Assuntos
Candidíase Vulvovaginal/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Adolescente , Adulto , Feminino , Humanos , Gravidez , Prevalência , Estudos Retrospectivos , Fatores de Risco , Espanha
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