1,720,976 research outputs found
Preoperative chemoradiation versus short term radiation alone with delayed surgery for stage II and III resectable rectal cancer
No full textThe aim of the randomized controlled trial was to compare the results of two different treatment options for stage II and III resectable rectal cancer: preoperative chemoradiotherapy and short term radiotherapy with delayed surgery (6 weeks). The objectives of the study were as follows: 1. to perform systematic literature review and meta-analysis comparing preoperative chemoradiotherapy with short-term radiotherapy 2. to compare radical resection rates between the groups; 3. to compare sphincter saving procedure rates; 4. to compare morbidity and mortality rates; 5. to evaluate the rates of downstaging and the rates of complete response; 6. to assess the role of preoperative treatment on the number of lymph nodes and the number of metastatic lymph nodes detected in the tumor bearing specimen. Arms 1. chemoradiotherapy arm - radiotherapy 50Gy/25fr, 1.8-2Gy per fraction over 5 weeks with chemotherapy 5-Fu/Lv ( 400mg/m² 5-Fluouracil, 20mg/m² Leucovorine) during first and last week of radiotherapy ( surgery after 6-7 weeks). 2. short-term radiotherapy with delayed surgery arm – radiotherapy 25Gy/5fr, 5Gy per fraction over 5 days (surgery after 6-7 weeks). preoperative short term radiation group 5x5 Gy during 5 days and surgery after 6 weeks Inclusion Criteria: • histologically confirmed stage II and III rectal cancer less than 15 cm from anal verge • less than 80 years old • no other cancer during 5 years period • compensate cardiovascular, pulmonary, hepatic and renal functions
The comparative value of magnetic resonance tomography and computed tomography examinations for II and III stages of rectal cancer
No full textSUMMARY The aim and the goals of the study: To evaluate the precision of rectal cancer radiological diagnostics, comparing the rectal cancer stages before and after neoadjuvant therapy. Objectives of the study: 1. To evaluate the decrease of the II–III stages rectal cancer stage and size in the large fraction radiation treatment with delayed surgery group and combined small fraction chemoradiation treatment group by MRI and CT methods. 2. To assess and compare the precision of MRI and CT when determining the RC stages before and after the neoadjuvant treatment. 3. To assess the MRI and CT sensitivity and specificity when determining the RC response to the neoadjuvant treatment. 4. To evaluate the MRI–DW ADC numeric value margin, characteristic of rectal tumour tissue before and after the neoadjuvant therapy, as well as the trial sensitivity and specificity when assessing the RC response to the neoadjuvant therapy. Scientific novelty: This is the first randomized controlled trial in Lithuania assessing two methods of neoadjuvant treatment for stage II and III respectable rectal cancer Conclusions: 1. Statistically significant rectal tumour size, T and N stage reduction, as well as CRM variation were determined after the neoadjuvant treatment in the combined chemoradiation and large fraction radiation treatment groups by means of radiological diagnostics methods. 2. When assessing the neoadjuvant treatment effectiveness with examination before and after the neoadjuvant therapy, it was determined that tumour T variation evaluation is more precise when using MRI (the probability of T stage discrepancy is 3.36 vs. 3.16), and N stage variation evaluation is more precise when using CT (the probability of N stage discrepancy is 2.25 vs. 1.27), in comparison with the MRI trial. 3. When assessing the neoadjuvant treatment effectiveness by comparing radiological diagnostic methods with pathomorphological examination methods low sensitivity and specificity of the radiological examination methods were determined: the MRI sensitivity – 63.18% and specificity – 52.14% and CT, respectively – 63.74% and 61.94%. 4. The evaluation of residual tumour tissue after the neoadjuvant therapy MRI – DW showed high sensitivity and specificity indicators: sensitivity – 97.8%, specificity – 58.3%. Statistically significant tumour tissue before the neoadjuvant treatment and the recovered tumour tissue after the treatment ADC values were determined, respectively: 0.620×10–3 mm2/s and 1.080×10–3 mm2/s
Coloanal anastomosis in rectal cancer surgery
No full textPurpose. To determine the efficacy of proctectomy with coloanal anastomosis for adenocarcinoma of the lower third of the rectum, and to compare quality of life after colonal anatomosis with low anterior rectal resection. Material and methods. Twenty coloanal anatomosies were performed on 1996\u962001 in Kaunas Medical University Hospital. Coloanal anatomosis was performed due to 1 villous adenoma and 19 adenocarcinomas. Postoperative functional results and quality of life were assesed by questionnaire, which was sent by mail to 17 patients after coloanal anatomosis and randomly assigned to 35 patients after low anterior rectal resection. Questionnaire was answered by 10 patients (59%) after coloanal anatomosis and 23 patients (66%) after low anterior rectal resection. Results. Four general and 7 surgical complications occurred after coloanal anatomosis. Postoperative mortality was 15% (3 cases). Symptomatic anastomotic strictures revealed in 2 patients. The frequency of defecation 6 and more times per day after coloanal anatomosis were in 2 cases (20%) and after low anterior rectal resection in 3 cases (13%). In coloanal anatomosis group normal continence occurred in 40% of cases and after low anterior rectal resection \u96 in 65%. One patient had incontinence of solids after low anterior rectal resection. In 4 cases after low anterior rectal resection occurred stable urine dysfunction. In coloanal anatomosis group sexual dysfunction occurred in 30% of cases, after low anterior rectal resection \u96 in 22%. After both operations about 50% patients felt better. Hard social, emotional problems had only one patient with incontinence of solids. In other aspects quality of life was similar in both groups. Conclusions. Proctectomy with coloanal anastomosis is suitable and safe procedure to treat lower third rectal cancer, with functional results and quality of life similar to low anterior rectal resection
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
The Role of the regional (intraarterial) chemotherapy in the treatment of colorectal cancer metastatic to the liver
No full textThis focuses on review one of the methods of locoregional treatment \u96 intraarterial hepatic infusion. Metastatic hepatic malignancies are the leading cause of cancer death. Surgical resection of metastatic hepatic malignancies has been the only established treatment modality offering potential for cure. Although surgical resection has significantly improved survival, only 5\u9620 percent of patients with colorectal carcinoma metastatic to the liver are surgical candidates. Conventional systemic (intravenous) chemotherapy with fluoropirimidines is effective only for 10\u9621 percent of patients with metastatic colorectal carcinoma. The limitations of surgical resection and the limited efficacy and generalized toxicity of systemic chemotherapy have sparked considerable interest in intraarterial hepatic infusion and especially in combination of systemic and intraarterial chemotherapy
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