Performance of the QuantiFERON®-TB Gold In-Tube assay in tuberculin skin test converters: a prospective cohort study.

OBJECTIVE: To investigate diagnostic agreement of the QuantiFERON®-TB Gold In-Tube (QFT-GIT) test in adult tuberculin skin test (TST) converters in a high tuberculosis (TB) burden setting. SETTING AND DESIGN: We performed a case-cohort study from 2014 to 2016 in Uganda among residents who were not infected with Mycobacterium tuberculosis. Participants were followed up for 1 year, when they were retested to determine TST conversion. All TST converters and a random sample of participants from baseline were offered QFT-GIT testing. RESULTS: Of 368 enrolled participants, 61 (17%) converted their TST by 1 year. Among 61 converters, 42 were tested using QFT-GIT, 64% of whom were QFT-GIT-positive. Of 307 participants with a persistent negative TST, 48 were tested using QFT-GIT, 83% of whom were QFT-negative. Overall concordance of TST and QFT-GIT was moderate (κ = 0.48, 95%CI 0.30-0.66). Converters with a conversion of 15 mm had a higher proportion of concordant QFT-GIT results (79%) than converters with increments of 10-14.9 mm (52%). CONCLUSION: Concordance between TST and QFT-GIT was moderate among TST converters in this urban African population. These findings call for improved tests that more accurately measure conversion to tuberculous infection.

Estudio de la frecuencia de parpadeo y evaluación de la película lagrimal en superficie ocular de cobayos / Eye blinking frequency studies and tear film evaluation in guinea pig's ocular surface

OBJETVOS: La Queratopatía Climática Esferoidea (QCE) es una enfermedad degenerativa de la córnea humana caracterizada por la agregación de proteínas bajo el epitelio y una progresiva opacidad corneal, causada por condiciones ambientales desfavorables. Si bien esta patología fue descripta por primera vez hace más de cien años, en la actualidad no existe un modelo experimental de QCE que permita avanzar en el conocimiento de la etiopatogenia de la misma para plantear posibles tratamientos. En el intento por desarrollar este modelo en cobayos y debido a la escasa bibliografía disponible que describa la anatomía, fisiología y superficie ocular de estos animales, realizamos diferentes tests fisiológicos de superficie ocular en cobayos y lo compararemos con el humano. MÉTODOS: Para estos estudios se utilizaron 15 cobayos. Se realizaron videograbaciones de los mismos en un ambiente de tranquilidad y bajo ciertos estímulos para estudiar la dinámica de parpadeo y sueño. Con el fin de analizar la producción y la estabilidad del film lagrimal, se realizaron test de Schirmer, medición de la altura del menisco lagrimal inferior por OCT visante y tiempo de ruptura precorneal (TRP) respectivamente. RESULTADOS: El cobayo parpadea de forma completa y parcial, siendo más frecuente ésta última modalidad. La frecuencia y tipo de parpadeos/ minuto fue: Total= 2.35± 0.87; completos= 0.68±0.43; parciales=1.49±0.75. Su frecuencia de parpadeo es 5 veces menor que en humanos. La respuesta palpebral frente a diferentes estímulos externos fue escasa. Los cobayos no poseen hábitos nocturnos como muchos roedores y duermen por cortos períodos. A menudo no cierran completamente los ojos. Test de Schirmer cobayos: 8.14±1.86 mm/5 min (Humanos: 11.9 ± 6.79 mm/5 min). Altura menisco inferior cobayos: 0,206 ± 0,059 mm (Humanos: 0,277 ± 0,033 mm). TRP cobayos: 2-3 min. (Humanos: 10-15 seg). CONCLUSIONES: Los resultados obtenidos muestran que el cobayo, a diferencia de humanos, tiene una frecuencia de parpadeo menor. A su vez, esto se puede correlacionar con una producción de lágrima disminuida (objetivada con Test de Schirmer) y una mayor estabilidad de la película lagrimal, como lo evidencia el prolongado TRP. (AU)

PURPOSE: Climatic spheroidal keratophaty (CSK), also known as climatic droplet keratopathy (CDK), is a degenerative human corneal disease characterized by protein aggregation under the corneal epithelium that leads to a progressive corneal opacity. Of unknown etiology, it is related to harsh environmental conditions. Although CSK was described many years ago and no experimental model of the disease is still available, we perform different physiological test on the guinea pig´s ocular surface and compare the results with human parameters. METHODS: 15 guinea pigs were used for this study. Video recordings of their behavior in a quiet environment and under certain stimulus were performed to study the blinking and sleeping dynamic. Test de Schirmer, Inferior tear meniscus height measurement, Break up time (BUT) test were performed, with the aim of analyze the tear film production and stability. RESULTS: The guinea pig blinks in both a complete and a partial way, being more frequent the last one. The blink type and frequency were: Total = 2.35± 0.87; complete= 0.68±0.43; partial=1.49±0.75. The blink frequency is 5 times smaller than in humans. The eyelid response against different external stimuli was poor. The night habits of this animals were different compared with other rodents, they sleep for a short periods of time. They often do not close their eyes completely. Schirmer test in guinea pigs was 8.14±1.86 mm/5 min (humans: 11.9 ± 6.79 mm/5 min). Inferior tear meniscus height measurement in guinea pigs was 0,206 ± 0,059 mm (humans: 0,277 ± 0,033 mm). BUT in Guinea Pig: 2-3 min. (Humans: 10-15 seg). CONCLUSIONS: Guinea Pigs have a short blink frequency unlike humans, a decreased tear production, and an increased tear film stability. (AU)

Bevacizumab intravítreo en el tratamiento de las oclusiones venosas de la retina / Bevacizumab in the treatment of macular edema complicating retinal vein occlusions

INTRODUCCIÓN: Dentro de las vasculopatías retinianas, las oclusiones venosas de la retina (OVR) representan la segunda causa más frecuente de pérdida de visión luego de la retinopatía diabética. Se han descripto dos tipos diferentes de OVR: la oclusión de vena central de la retina (OVCR), y la oclusión de rama venosa retinal (ORVR). De acuerdo al compromiso oclusivo del lecho capilar de la retina, se las clasifica en isquémicas (o no perfundidas), y no isquémicas (perfundidas), presentando una patogénesis, diagnóstico, pronóstico y tratamiento diferente. Se ha demostrado que los niveles de factor de crecimiento vascular endotelial (VEGF) aumentan significativamente en las oclusiones venosas retinianas, lo que tiene como consecuencia una disfunción de la barrera hematorretinal y el aumento de la permeabilidad vascular, con el consecuente edema macular. La inyección intravítrea de bevacizumab, un anticuerpo monoclonal recombinante que actúa en forma directa contra cualquier forma activa de VEGF, ha demostrado ser efectiva para reducir el espesor macular y mejorar la agudeza visual en el tratamiento de OVR. OBJETIVO: Evaluar los cambios en la agudeza visual y en los espesores maculares de pacientes con oclusiones venosas retinianas tratados con inyecciones intravítreas de bevacizumab. Pacientes y métodos: Se evaluaron retrospectivamente 39 pacientes con diagnóstico de oclusión venosa retiniana (OVR) complicada de edema macular y tratados mediante inyección intravítrea de 1,25 mg/0,05 ml bevacizumab (Avastin®, Roche Diagnostic GmbH, Manheim, Alemania), con un seguimiento mínimo de 18 meses. La agudeza visual se evaluó mediante tabla de Snellen y se convirtió en unidades LogMAR. El espesor macular se evaluó mediante tomografía de coherencia óptica (OCT). Según la presentación clínica se las clasificó en: 1. Oclusión de rama (ORVR), incluyendo las oclusiones hemisféricas y 2. Oclusión de vena central (OVCR), incluyendo oclusión venosa hemicentral. A su vez, mediante angiografía fluoresceínica se las clasificó en oclusiones predominántemente isquémicas, y predominántemente no isquémicas. Las variables cuantitativas se analizaron mediante medidas de tendencia central, dispersión y forma. Los cambios en la agudeza visual se calcularon utilizando la prueba de Wilcoxon. Las diferencias entre variables continuas fueron calculadas mediante la prueba T de Student para variables paramétricas, y Mann Whitney para variables no paramétricas. RESULTADOS: La edad promedio fue de 66,8 años (DE: 13,65; rango= 31-92 años). El 55% de los casos estudiados fueron OVCR y el 37,5% ORVR. La media del total de inyecciones durante los 18 meses de seguimiento fue de 4,11±1,61 (rango= 1 a 6). La terapia con láser de rescate se realizó en 10 (25%) pacientes. Todos los pacientes que debieron ser tratados con láser tuvieron una AV inferior a 1 décima al final del seguimiento. La agudeza visual promedio al inicio del tratamiento fue de 1,092 con una desviación estándar (DE) de 0,36, con un rango de 0,10 y 1,60. Tras el inicio del tratamiento, todos los grupos de pacientes logran un incremento significativo en la AV (P= <0,0001). A los 18 meses de tratamiento la agudeza visual promedio fue de 0,739 con una DE de 0,45 con un rango de entre 0,00 y 1,50. La agudeza visual media de los pacientes con OVCR antes del tratamiento fue de 1,09 (DE: 0,35; rango= máxima 0,50 y mínima 1,60), y a los 18 meses de tratamiento de 0,87 (DE: 0,73; rango= 0,20 a 1,50). En cambio, los pacientes con ORVR antes del tratamiento presentaron una media de 1,10 (DE: 0,31; rango= máxima de 0,40 y mínima de 1,6), y luego del tratamiento una media de 0,53 (DE: 0,38; rango= máxima 0,1 y mínima 1,2). El 54,5% de los casos fue de predominio isquémico o mixtos, y el 43,5% fue a predominio edematosos al inicio del tratamiento. La agudeza visual media de los pacientes con tipo edematoso fue de 0,93 (DE: 0,34; rango= máxima 0,10 y mínima 1,40), mientras que los pacientes con patología isquémica presentaron una media de 1,25 (DE: 0,32; rango= máxima de 0,40 y mínima de 1,6). Ambos grupos respondieron en forma significativa al tratamiento (p< 0.05). Sin embargo, los pacientes con predominio edematoso lograron una mejoría mayor que aquellos con predominio isquémico. (P=0.0054) La agudeza visual media de los pacientes con predominio edematoso a los 18 meses del tratamiento fue de 0,50 (DE: 0,44; rango= máxima 0,0 y mínima 1,40), mientras que los pacientes con predominio isquémico presentaron una media de 0,97 (DE: 0,35; rango= máxima 0,20 y mínima 1,4). La media de los espesores maculares previo al inicio del tratamiento fue de 654.19 ± 272.05 micras (rango= 215 a 1497 micras), mientras que la media luego del tratamiento fue de 449 ± 247,62 micras (rango= 140 a 1005 micras) (p=0,0009). No hubo efectos colaterales ni complicaciones locales ni sistémicas atribuibles a la inyección de bevacizumab durante el seguimiento. CONCLUSIÓN: El bevacizumab fue eficaz en el tratamiento del edema macular secundario a OVR. La respuesta terapéutica fue mayor en las ORVR. En nuestra serie no hubo complicaciones oculares ni sistémicas vinculadas al tratamiento. (AU)

INTRODUCTION: Within the retinal vascular disease,retinal venous occlusion (RVO) represents the second most common cause of vision loss after diabetic retinopathy. In turn, it is estimated that the RVO affects approximately 1.6% of people worldwide. It has been described two different types of RVO: the central retinal vein occlusion (CRVO), which includes the hemicentral retinal vein occlusion (HCRVO), and the branch retinal vein occlusion (BRVO), which includes Major BRVO (occlusion of a retinal vein that drains one of the quadrants or more), Minor BRVO (occlusion of a retinal vein that drains less than a quadrant) and Hemispheric retinal vein occlusions (half or more of the retina). According to the occlusive pattern of the retinal capillary bed, this disease is classified as ischemic (or non perfused); when the areas of noncapillary perfusion, seen under fluorescein angiography, have an extension of more than 10 disc diameters; and non-ischemic (o perfused), presenting a pathogenesis, diagnosis, prognosis and different treatment. Non-ischemic form is generally more benign, with a less dramatic visual impairment, a greater chance of spontaneous recovery, a better treatment response, and generally has no risk of neovascularization. Instead; ischemic form is much more severe, causing a more dramatic visual acuity decline, with little chance of clinical improvement, an increased risk of blindness and an increased risk of neovascularization. Although the physiopathogenesis of OVR is not accurately known, it is suggested that the thickening and stiffness of arteries and arterioles caused by arteriosclerosis leads to compression of the retinal veins at the sites where adventitia is shared with arteries (in its intraneural route to the optic nerve and the arteriovenous crossings), leading eventually to a turbulent blood flow, damage to endothelial cells, thrombus formation and eventual vein occlusion. This theory is supported by studies showing pathological structural changes in veins and arteries of patients with VO. Moreover, other factors related to venous deregulation, such as inadequate vasoconstriction and increased vascular permeability, could also play an important role in the retinal venous occlusive phenomena. In some patients, especially young people and adults under 50 years old, inflammatory disorders and hypercoagulable states may contribute to the hysiopathogenesis of the RVO. It has been shown that the presence of vascular endothelial growth factor (VEGF) increased significantly the chances to develop retinal vein occlusions. The result is a blood­retinal barrier dysfunction and an increased vascular permeability, with consequent macular edema. It has also been reported that VEGF plays an important role in the pathogenesis of macular edema in both ORV and CRVO.10 While there is insufficient level 1 evidence to support OVR treatment, multiple therapeutic possibilities have been described, such as anticoagulation, intravitreal fibrinolysis, hemodilution, laser photocoagulation, laser-induced anastomosis, radial optical neurotomy, adventiciotomía, intravitreal injection of triamcinolone acetonide, intravitreal injection of dexamethasone, and injection intravitreal antiangiogenic monoclonal antibodies, such as ranibizumab, bevacizumab, and aflibercept, alone or associated with photocoagulation, have shown efficacy and variables complications rates. Intravitreal injection of bevacizumab, a recombinant monoclonal antibody that acts directly against any active form of VEGF, has been shown to be effective in reducing macular thickness and improving visual acuity in the treatment of OVR. However, the need for multiple injections has been reported since the effects of intravitreal bevacizumab (as well as the other antiangiogenics) are short-lived. On one hand, Bevacizumab has the disadvantage that it is administered off-label; in addition each dose must be extracted from a vial for oncological use, which represents a risk of contamination if strictly rules of asepsis are not taken. On the other hand, the cost of each dose is lower than that of other products (ranibizumab, aflibercept) already approved for intraocular use. This allows that more patients have access to a prolonged treatment in underdeveloped or developing countries, such as Argentina. PURPOSE: To evaluate changes in visual acuity and macular thickness after intravitreal bevacizumab for the treatment of macular edema in patients with retinal vein occlusions (RVO). PATIENS AND METHODS: 39 consecutive patients with macular edema complicating RVO and treated with intravitreal injections of bevacizumab 1.25 mg/0.05 ml alone or associated with scattered peripheral laser photocoagulation, with a minimun follow-up of 18 months, were evaluated. Snellen visual acuity in LogMar units and macular thinckness measured by optical coherence tomography (OCT) were the end points. According to clinical and fluorescein angiographic presentation RVO were classified in branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO), and in non ischemic and ischemic. Wilcoxon test for paired variables, Mann Whitney for independant variables, and Student test for continuous variables, were used for statistical analysis. RESULTS: With a mean age of 66.8 years (SD: 13.65; range= 31-92 years), 62.5% of cases were CRVO and 37.5% BRVO. Mean number of injections was 4.11±161 (range= 1-6). Laser was performed in 25% of patients that did not respond to bevacizumab. At 18 months of follow-up, improvement of visual acuity and macular thickness was statistically significant (p=0.0001 and p=0.0009 respectively). BRVO showed better response to treatment than CRVO. Best visual results were obtained at first month (median= 1.00 P25= 0.5 P75= 1.30) and at 9 month (median= 0.8 P25= 0.5 P75= 1.20) after first injection, but no further improvement was observed beyond 9 months of treatment (p=0.84). No significant visual and macular thickness differences were obtained between patients treated with bevacizumab alone (p=0.116) and bevacizumab and laser (p=0.846). No ocular or systemic attributable-to-treatment side effects were observed. CONCLUSIONS: Bevacizumab was effective in improving visual acuity and reducing macular thinckness in patients with macular edema complicating RVO, especially in BRVO. No ocular or systemic complications were observed during follow-up. (AU)

Bayesian analysis of a disability model for lung cancer survival.

Bayesian reasoning, survival analysis and multi-state models are used to assess survival times for Stage IV non-small-cell lung cancer patients and the evolution of the disease over time. Bayesian estimation is done using minimum informative priors for the Weibull regression survival model, leading to an automatic inferential procedure. Markov chain Monte Carlo methods have been used for approximating posterior distributions and the Bayesian information criterion has been considered for covariate selection. In particular, the posterior distribution of the transition probabilities, resulting from the multi-state model, constitutes a very interesting tool which could be useful to help oncologists and patients make efficient and effective decisions.

IMP-3 expression in keratoacanthomas and squamous cell carcinomas of the skin: an immunohistochemical study.

The protein insulin-like growth factor II mRNA binding protein 3 (IMP3) is an important factor for cell migration and adhesion in malignancies. Recent studies have shown a remarkable overexpression of IMP3 in different human malignant neoplasms and also revealed it as an important prognostic marker in some tumor entities. The purpose of this study is to compare IMP3 immunostaining in squamous cellular skin tumor and determine whether IMP3 can aid in the differential diagnosis of these lesions. To our knowledge, IMP3 expression has not been investigated in skin squamous cell proliferations thus far. Immunohistochemical staining for IMP3 was performed on slides organized by samples from 67 patients, 34 with keratoacanthoma and 33 with primary squamous cell carcinoma (16 invasive and 17 in situ). The majority of our KAs (25/34) were negative for IMP-3 staining. The majority of SCCs (19/33) are positive for IMP3 staining. The percentage of IMP3 positive cells increases significantly in group SCC (p=0.0111), and in particular in the SCC in situ group (p=0.0021) with respect to the KA group.  IMP3 intensity staining increases significantly in SCCs (p=0.0213), and particularly in SCCs (p=0.008) with respect to KA. Our data show that IMP3 expression is different in keratoacanthomas with respect to squamous cell carcinoma. IMP3 assessment and staining pattern, together with a careful histological study, can be useful in the differential diagnosis between KA e SCC.

The usefulness of c-Kit in the immunohistochemical assessment of melanocytic lesions.

C-Kit (CD117), the receptor for the stem cell factor, a growth factor for melanocyte migration and proliferation, has shown differential immunostaining in various benign and malignant melanocytic lesions. The purpose of this study is to compare c-Kit immunostaining in benign nevi and in primary and metastatic malignant melanomas, to determine whether c-Kit can aid in the differential diagnosis of these lesions. c-Kit immunostaining was performed in 60 cases of pigmented lesions, including 39 benign nevi (5 blue nevi, 5 intradermal nevi, 3 junctional nevi, 15 cases of primary compound nevus, 11 cases of Spitz nevus), 18 cases of primary malignant melanoma and 3 cases of metastatic melanoma. The vast majority of nevi and melanomas examined in this study were positive for c-Kit, with minimal differences between benign and malignant lesions. C-Kit cytoplasmatic immunoreactivity in the intraepidermal proliferating nevus cells, was detected in benign pigmented lesions as well as in malignant melanoma, increasing with the age of patients (P=0.007) in both groups. The patient's age at presentation appeared to be the variable able to cluster benign and malignant pigmented lesions. The percentage of c-Kit positive intraepidermal nevus cells was better associated with age despite other variables (P=0.014). The intensity and percentage of c-Kit positivity in the proliferating nevus cells in the dermis was significantly increased in malignant melanocytic lesions (P=0.015 and P=0.008) compared to benign lesions (compound melanocytic nevi, Spitz nevi, intradermal nevi, blue nevi). Immunostaning for c-Kit in metastatic melanomas was negative. Interestingly in two cases of melanoma occurring on a pre-existent nevus, the melanoma tumor cells showed strong cytoplasmatic and membranous positivity for c-kit, in contrast with the absence of any immunoreactivity in pre-existent intradermal nevus cells. C-Kit does not appear to be a strong immunohistochemical marker for distinguishing melanoma from melanocytic nevi, if we consider c-Kit expression in intraepidermal proliferating cells. The c-Kit expression in proliferating melanocytes in the dermis could help in the differential diagnosis between a superficial spreading melanoma (with dermis invasion) and a compound nevus or an intradermal nevus. Finally, c-Kit could be a good diagnostic tool for distinguishing benign compound nevi from malignant melanocytic lesions with dermis invasion and to differentiate metastatic melanoma from primary melanoma.

The role of genomic and antigenomic HCV-RNA strands as predictive factors of response to pegylated interferon plus ribavirin therapy.

BACKGROUND: Hepatitis C virus replicates by the synthesis of an antigenomic HCV-RNA. As the end point of anti-viral therapy is to decrease viral replication, the amount of antigenomic HCV-RNA could influence the response. AIM: To study if amounts of genomic and antigenomic HCV-RNA in the baseline liver biopsy are predictive factors of response to anti-viral therapy. METHODS: Eighty-eight patients with chronic HCV infection (anti-HIV-negative) treated with pegyltaed-interferon-alpha2b plus ribavirin for 12 months were included. Intrahepatic genomic and antigenomic HCV-RNA concentrations were determined by real-time polymerase chain reaction and percentage of infected hepatocytes by in situ hybridization. RESULTS: Of the 88 patients, 31% were responders while 69% were not. Median of antigenomic HCV-RNA in liver of responders and non-responders was 120 000 copies/microg RNA (range: 10,000-775,000) vs. 150,000 copies/microg RNA (range: 100-3,200,000; P = 0.38). Median of genomic HCV-RNA in liver of responders was 1,250,000 copies/microg RNA (range: 5000-9,000,000) and in non-responders 3,180,000 copies/microg RNA (range: 4600-18,000,000; P = 0.0191). Predictive factors of response in the logistic regression were: intrahepatic amount of genomic HCV-RNA, percentage of infected hepatocytes and previous therapy. CONCLUSION: Response to 12 months of therapy with pegylated interferon-alpha2b plus ribavirin depends on the amount of genomic HCV-RNA in the pre-treatment liver biopsy.

La biopsia mediante sutura en bolsa de tabaco presuturada en el diagnóstico y tratamiento de los pólipos umbilicales. Réplica / Biopsy by presutured purse-string suture in the diagnosis and treatment of umbilical polyps. Reply

No disponible

No disponible

[Persistence of the omphalomesenteric duct. Childhood differential diagnosis of umbilical granuloma]. / Persistencia del conducto onfalomesentérico. Diagnóstico diferencial de granuloma umbilical en la infancia.

The omphalomesenteric duct is an embryonic structure which communicates the vitelline duct with the midgut. It normally disappears between the fifth and ninth weeks of intrauterine life. Anomalies related with the total or partial absence of this involution are show in 2 % of the population. We report a case of persistence of the omphalomesenteric duct and review the bibliography to establish the differences between this anomaly and umbilical granuloma, which is the main differential diagnosis.

Persistencia del conducto onfalomesentérico. Diagnóstico diferencial de granuloma umbilical en la infancia / Persistence of the omphalomesenteric duct. Childhood differential diagnosis of umbilical granuloma

El conducto onfalomesentérico es una estructura embrionaria que comunica al saco vitelino con el intestino medio que generalmente desaparece entre la quinta y la novena semanas de vida intrauterina. Las anomalías relacionadas con la ausencia total o parcial de dicha involución se presentan en un 2 % de la población. Presentamos un caso de persistencia del conducto onfalomesentérico y realizamos una revisión bibliográfica para establecer las diferencias que existen entre esta anomalía y el granuloma umbilical que es su principal diagnóstico diferencial

The omphalomesenteric duct is an embryonic structure which communicates the vitelline duct with the midgut. It normally disappears between the fifth and ninth weeks of intrauterine life. Anomalies related with the total or partial absence of this involution are show in 2 % of the population. We report a case of persistence of the omphalomesenteric duct and review the bibliography to establish the differences between this anomaly and umbilical granuloma, which is the main differential diagnosis

Sistemas de contención de órganos en movimiento: Radioterapia Adaptada a la Respiración (RAR) / Content systems of moving organs: radiotherapy adapted to respiration (RAR)

No disponible

[Partial breast irradiation: high dose rate peroperative brachytherapy technique using the MammoSite]. / Irradiation partielle du sein: technique de curiethérapie de haut débit de dose après l'implantation peropératoire du dispositif MammoSite.

In the conservative management of breast cancer, radiation therapy delivering 45 to 50 Gy to the whole breast, in 4.5 to 5 weeks, followed by a booster dose of 10 to 20 Gy is the standard of care. Based on the numerous studies which have reported that the local recurrences occurs within and surrounding the primary tumor site and in order to decrease the treatment duration and its morbidity, partial breast irradiation using several techniques has been developed. Partial irradiation may be considered as an alternative local adjuvant treatment for selected patients with favorable prognostic factors. Using external beam radiation therapy, the 3D-conformal technique is appropriate to deliver the whole dose to a limited volume. In UK, an intraoperative technique using a miniature beam of low energy of x-ray (50 Kv) has been developed (Targit). Milan's team have developed an intraoperative electrons beam radiotherapy using a dedicated linear accelerator in the operative room. In USA and Canada the MammoSite has been advised for clinical use in per-operative brachytherapy of the breast. These two last techniques are currently compared in phase III randomised studies to the standard whole breast irradiation followed by a tumour bed booster dose. In this review we will focus on the MammoSite technique and will describe the per-operative implantation procedure, radiological controls ad dosimetric aspects.

[Impact of medical counselling on giving up smoking during pregnancy]. / Impacto del consejo médico para dejar de fumar durante la gestación.

OBJECTIVE: Women s tobacco consumption has increased in Spain in recent years, especially among women of reproductive age. This study aims to evaluate the impact of medical counselling integrated into pre-natal care on tobacco consumption during pregnancy and the period after delivery. DESIGN: Quasi-experimental intervention study.Setting. Hospital del Mar, Barcelona. PATIENTS: 219 patients who attended the Hospital del Mar for delivery during 1996 (control group) and 169 patients seen during their pregnancies at the same hospital in 1997 (intervention group). INTERVENTIONS: The control group patients had received normal care. The pregnant women in the intervention group received systematic structured counselling on giving up smoking, backed up by a special brochure composed for this purpose. MEASUREMENTS AND RESULTS: The intervention and control groups showed no statistically significant differences either in their social or demographic variables or in their tobacco consumption. In both groups the evolution of their smoking during pregnancy was determined during their pre-natal visits and six months after delivery through a telephone interview. 44 of the women in the control group (20.1%) gave up smoking before their first pre-natal visit, and 11 (5%) gave up during pregnancy. In the intervention group 26 (17.7%) had given up spontaneously and 16 (10.9%) gave up during pregnancy. Of those who gave up completely during pregnancy, 36.4% of women in the control group and 64.3% in the intervention group remained abstinent at six months (P=.002). CONCLUSIONS: Counselling at pre-natal check-ups to give up smoking lightly increases the number of women who give up and reduces significantly the number of post-delivery backsliders.

Impacto del consejo médico para dejar de fumar durante la gestación / Impact of medical counselling on giving up smoking during pregnancy

Objetivo. El consumo de tabaco entre las mujeres ha aumentado en España en los últimos años, especialmente entre los grupos en edad reproductiva. El objetivo del estudio es evaluar el impacto del consejo médico integrado en la atención prenatal sobre el consumo de tabaco durante el embarazo y en el posparto. Diseño. Estudio de intervención cuasiexperimental. Emplazamiento. Hospital del Mar de Barcelona. Pacientes. El grupo control estaba constituido por 219 pacientes que acudieron para atención al parto al hospital del Mar en 1996, el grupo de intervención, por 169 pacientes atendidas durante el embarazo en el mismo hospital en 1997.Intervenciones. Las pacientes del grupo control habían recibido atención habitual. Las gestantes del grupo de intervención recibieron de forma sistemática un consejo estructurado para dejar de fumar, reforzado por un folleto elaborado con esta finalidad. Mediciones y resultados. Los grupos de intervención y control no presentaban diferencias estadísticamente significativas en las variables sociodemográficas ni en el consumo de tabaco. En ambos grupos se determinó la evolución del hábito tabáquico durante el embarazo a lo largo de las visitas prenatales, y a los 6 meses posparto, a través de una entrevista telefónica. De las gestantes del grupo control, 44 (20,1 per cent) habían dejado de fumar antes de la primera visita prenatal y 11(5 per cent) lo hicieron durante el embarazo. En el grupo de intervención 26 (17,7 per cent) habían dejado de fumar espontáneamente y 16 (10,9 per cent) dejaron de fumar durante el embarazo. De las que dejaron de fumar completamente durante el embarazo, se mantenían abstinentes a los 6 meses el 36,4 per cent de las mujeres del grupo de control y el 64,3 per cent en el grupo de intervención (p = 0,002). Conclusiones. El consejo para dejar de fumar en la visita prenatal produce un aumento discreto en la proporción de abandonos, y una disminución significativa de las recaídas en el posparto. (AU)

Validez del consumo declarado de tabaco en el embarazo / Validity of pregnant women´s stated tobacco consumption

Objetivos. Analizarla relación entre el consumo de tabaco declarado por las embarazadas que declaran fumar antes de la gestación y los niveles de cotinina en orina al inicio y al final de la gestación. Diseño. Estudio observacional, longitudinal. Participantes. Grupo de estudio: 147 gestantes que acuden a primera visita de control prenatal a consultas externas del Hospital del Mar de Barcelona durante 1997. Grupo de control: 50 gestantes no fumadoras atendidas para control de embarazo durante 1997. Mediciones. Número de cigarrillos que declaran fumar al día en la primera visita de control en nuestro centro y en la última visita antes del parto. Niveles de cotinina en las orinas aportadas a dichas visitas. Resultados. La media de cotinina en las gestantes que declaran haber dejado de fumar es superior a la de las no fumadoras. Existe una relación lineal estadísticamente significativa entre el número de cigarrillos declarados y los niveles de cotinina en la primera visita y en la última visita de control gestacional, así como entre la variación de número de cigarrillos y niveles de cotinina entre ambas visitas. El valor predictivo negativo de la declaración del habito tabáquico es del 82,9 por ciento. Conclusiones. Se observa cierto grado de infradeclaración entre las gestantes fumadoras, si bien hay una buena correlación entre declaración de consumo y niveles de cotinina. La infradeclaración no aumenta a pesar del consejo reiterado para dejar de fumar, por lo que, a pesar de sus limitaciones, puede ser un indicador útil para evaluar el efecto de las intervenciones orientadas a promover el abandono del tabaquismo durante la gestación (AU)

El abandono del tabaquismo durante la gestación y la recaída / Smoking cessation during pregnancy and relapses

Introducción El hábito tabáquico en las mujeres españolas está aumentando, especialmente entre las mujeres de 25 a 44 años, que es el grupo con una tasa de fertilidad más elevada. Por tanto, existe una preocupación creciente por el aumento del riesgo asociado al tabaco, de forma directa a las mujeres y de forma indirecta a los fetos y a los hijos. Sin embargo, estas mujeres realizan muchos contactos con el sistema sanitario y son muy sensible a los mensajes sanitarios, especialmente durante el embarazo. Objetivo: Evaluar la prevalencia del hábito tabaco en nuestra población de mujeres gestantes. Evaluar la proporción de mujeres que dejan de fumar durante el embarazo. Analizar los factores que podrían influir en esta tasa de abandono. Material y métodos: Setecientas seis mujeres gestantes que recibieron atención al parto en el Hospital Universitario del Mar durante los meses de enero a diciembre de 1996. Cuestionario personal retrospectivo en la estancia hospitalaria postparto y obtención de datos de las historias clínicas. Encuesta telefónica a los 6 meses postparto.Resultados: El 31 por ciento de las mujeres eran fumadoras en el momento del diagnóstico del embarazo. El 20,1 por ciento dejó de fumar antes de la primera visita prenatal y el 5 por ciento tras la primera visita y durante el primer trimestre de embarazo. Se logró seguimiento telefónico a los 6 meses en el 52 por ciento de las gestantes fumadoras, de las que un 36,4 por ciento afirmaron seguir sin fumar. La abstinencia fue más frecuente entre las gestantes que fumaban menos y las que siguieron un mejor control prenatal, mientras que la mayor incidencia de recaídas se produjo entre las que fumaban más antes de la gestación y las que no realizaron lactancia materna.Conclusiones: Nuestra población de gestantes presenta una alta prevalencia de tabaquismo. El abandono del hábito tabáquico durante la gestación y a largo plazo es inferior a los datos encontrados en la literatura. El conocimiento de este problema nos ha llevado a desarrollar un proyecto para evaluar el impacto del consejo para dejar de fumar integrado a la consulta antenatal sobre la tasa del abandono del hábito tabáquico durante el embarazo y a largo plazo (AU)

[Validity of the declared tobacco consumption in pregnancy]. / Validez del consumo declarado de tabaco en el embarazo.

OBJECTIVES: To analyse the relationship between the stated consumption of tobacco by pregnant women who say they smoked before pregnancy and the levels of cotinine in their urine at the start and end of pregnancy. DESIGN: Observational, longitudinal study. PARTICIPANTS: During 1997. STUDY GROUP: 147 pregnant women at their first pre-natal visit to outclinics of the Hospital del Mar. CONTROL GROUP: 50 non-smoker pregnant women monitored during their pregnancy. MEASUREMENTS AND MAIN RESULTS: The numbers of cigarettes per day that they said they smoked on their first monitoring visit to our centre and at the last attendance before giving birth were recorded. Cotinine levels in the urine samples taken on these visits were measured. Mean cotinine in pregnant women who said they had given up smoking was higher than in non-smokers. There was a statistically significant linear relationship between the number of cigarettes stated and cotinine levels at the first and last pregnancy monitoring visits, as well as between the variation in the number of cigarettes and cotinine levels at these two visits. The negative predictive value of what they said about their tobacco habit was 82.9%. CONCLUSIONS: There was a certain under-declaration by pregnant smokers, although their statements of consumption and cotinine levels correlated closely. The under-declaration did not increase despite reiterated advice to stop smoking, which means that, despite its limitations, it could be a useful indicator for evaluating the effect of interventions aimed at stopping women smoking during pregnancy.

[Use of a multileaf collimator for the production of intensity-modulated beams]. / Utilisation d'un collimateur multilames pour la production de faisceaux modulés en intensité.

In external radiotherapy, the use of intensity modulated fields has been proposed for tissue and non-homogeneity compensation or for the generation of conformal dose distributions. Multileaf collimators can be employed dynamically for the modulation of the X-ray field in two dimensions. Efficient dynamic collimation became possible due to advances in computer and linear accelerator technology. It presents a number of advantages over conventional methods such as the use of compensators. We have developed a program which calculates, from a given intensity distribution, the motion of the MLC leaves as a function of monitor units, and we have applied it on a Varian linear accelerator with a 40 pair multileaf collimator. The analysis of the experimental results demonstrates the feasibility and the potential of the method.

Evaluation of the scatter field for high-energy photon beam attenuators.

Based upon sector integration, a method has been developed to evaluate the scatter from attenuating beam modulators at any point in the field for arbitrarily shaped fields and attenuators with variable thickness. The method requires preliminary measurements of narrow and broad beam transmission fractions as a function of filter thickness and field size. The ratio Sp of the contribution from photons scattered by the attenuator to the non-attenuated primary contribution was derived from these measurements. Sp was determined for x-ray beam energies between 4 and 23 MV with brass and lead attenuators. This quantity was found to be practically independent of beam energy for a given field size and material. The variation of Sp as a function of slab thickness for attenuators covering the entire beam showed a maximum for a thickness of approximately one mean free path. This maximum represents about 6.0% of the transmitted primary dose for an extreme case of a very heavily (1.6 cm thick lead slab) attenuated 15 cm x 15 cm field. The 'scatter field', corresponding to the scatter contribution from the attenuator across the field, was calculated for different partial attenuators and wedges. The results show that this component has a limited influence on calculation of dose distribution, but should be taken into account in absolute dosimetry analysis for large fields and thick wedge filters.