1,720,995 research outputs found
Surgery for soft tissue sarcomas
No full textSoft-tissue sarcomas are rare tumours of extreme heterogeneity. The degree of malignancy, the dimensions, the spontaneous necrosis and vascular invasion are important prognostic factors. Surgery, curative in more than 90 % of cases, is the main therapy. Obtaining adequate surgical margins (wide or radical) is essential. An important surgical aggressiveness however requires more complex reconstructions (free flaps, motor units transplants, nerves and tendons grafts etc.). Resection margins are must be adequate or if not, the use of radiotherapy will improve local control. The effect of radiotherapy does not differ significantly whether it is used pre- or post-operatively. The first, however, most frequently leads to local complications. Interstitial brachytherapy and intra-operative radiotherapy have special advantages. Currently, with surgery combined with radiation therapy, the risk of local recurrence is less than 10 %. Loco-regional treatment (infusion of hyperthermia with TNF, neo-adjuvant chemotherapy, etc.) are reserved for non-operable patients and may produce a reduction in the neoplastic mass which allows conservative surgery in 85 % of cases
Combining limb-sparing surgery with radiation therapy in high-grade soft tissue sarcoma of extremities - Is it effective?
No full textBACKGROUND: Limb-sparing surgery in combination with radiation therapy is a well-established treatment for high-grade soft tissue sarcomas of the extremities. But selection of cases and optimal sequence of irradiation and surgery still remain controversial.
METHODS: 769 patients with a high-grade soft tissue sarcoma of the extremities, who underwent a limb-sparing surgery, were retrospectively reviewed. Group 1 (N = 89) was treated with neo-adjuvant radiation therapy, group 2 (N = 315) with adjuvant irradiation and group 3 (N = 365) with surgery alone.
RESULTS: After a mean follow up of 45 months 95 local recurrences occurred resulting in a local recurrence-free survival of 83.2% after 5 years and 75.9% after 10 years. Contaminated surgical margins (Odds ratio: 2.42) and previous inadequate surgeries (Odds ratio: 1.89) were identified as risk factors for failed local control. Neo-adjuvant radiation therapy provides the best local recurrence-free rate for 5 years (90.0%), whereas after 10 years (78.3%) adjuvant irradiation showed better local control. The metastatic-free rate was independent from achieved surgical margins (p = 0.179). Group 1 showed the highest rate of revision surgery (9.0%), followed by group 3 (5.5%) and group 2 (4.4%) (p = 0.085). However, the rate of irradiation-correlated side effects was higher in group 2 (15.2%) than in group 1 (11.2%) (p = 0.221).
CONCLUSION: Surgery has to be effective for successful local control and remains the mainstay of the treatment in combination with neo-adjuvant as well as adjuvant irradiation. In really wide or even radical resections the benefit of radiation therapy can be discussed as the irradiation induced side effects are not negligible
Osteoarticular allografts in paediatric bone tumor reconstruction of the knee
No full textOsteoarticular allografts represent a reconstructive option after bone tumor resection around the knee in growing children. The major advantage is the chance to preserve the growth plate of the remaining bone, but the disadvantage is the high failure rate eventually requiring definitive prosthetic replacement at skeletal maturity. We retrospectively reviewed 22 patients who underwent osteoarticular allograft reconstructions of the distal femur (16) or proximal tibia (6). There were 12 females and 10 males with an average age at surgery of 11 years (7-15). The diagnosis was osteosarcoma in 19 cases and Ewing sarcoma in 3. All patients underwent pre- and post-operative chemotherapy. At an average follow-up of 103 months (12-167), 18 patients (82%) were alive and 4 had died (18%). We observed 10 allograft failures requiring prosthetic replacement, 6 in distal femur and 4 in proximal tibia reconstructions. At last follow-up 8 allografts (36%) were still in place. Overall allograft survival was 79.6% at five and 45.8% at ten years. In distal femur, allograft survival was 86.2% at five and 59.1% at ten years. In proximal tibia, allograft survival was 62.5% at 5 years and 31.2% at 67 months. Average limb shortening was 3 cm (0- 5) in 8 patients with the allograft still in situ and 2 cm (0-4) in 10 patients after prosthetic replacement. Average MSTS functional score of the whole series was 25 (83.7%). The MSTS score of patients after revision with prosthetic replacement was 24 (80%) while patients who still had the allograft retained had an average MSTS scores of 26.8 (89.3%). In conclusion, osteoarticular allograft reconstruction of the knee after bone tumor resection in pediatric age can be considered a temporary solution with the aim to limit limb length discrepancy before definitive prosthetic replacement after skeletal maturity
LIPOSARCOMA MIXOIDE/A CELLULE ROTONDE: RISULTATI CLINICI DI 148 CASI
No full textIntroduzione: lo scopo di questo studio è di valutare i risultati clinici del trattamento multimodale dei pazienti affetti da liposarcoma mixoide/a cellule rotonde (MRCL) e di esaminare i fattori prognostici sul controllo locale e sistemico e sulla sopravvivenza.
Materiali e Metodi: sono stati revisionati i dati clinici e strumentali di 148 pazienti (89 maschi, 59 femmine) trattati nel nostro Centro negli ultimi 25 anni, con un follow-up medio di 73 mesi (min 6, max 257). La localizzazione dei MRCL è stata: arto inferiore in 129 casi (87%), arto superiore in 13 (9%) e tronco in 6 pazienti (4%). L’età media alla diagnosi era di 49 anni (min 16 - max 82). La diagnosi istologica è stata di liposarcoma a basso grado nel 49% dei casi e ad alto grado nel 51%. La dimensione del tumore era inferiore a 5 cm nel 23% dei pazienti, tra 5 e 10 cm nel 45% dei casi e maggiore di 10 cm nel 32% dei casi. Il tumore era alla prima presentazione nel 70% dei casi, mentre nel 18% dei casi si trattava di recidiva locale (RL) e nel restante 12% dei casi era stata eseguita una radicalizzazione di una precedente escissione inadeguata. La sola chirurgia è stata eseguita nel 29% dei casi, mentre sono state associate chemioterapia e/o radioterapia nel 71% dei casi. I margini chirurgici sono risultati radicali nel 1% dei casi, ampi nel 70%, marginali nel 28% e intra-lesionali nel 1%. Dopo l’escissione, in 15 casi è stato usato un lembo di copertura (di rotazione in 4 casi, libero in 11).Risultati: in 15 casi (10%) si è presentata una RL, trattata con escissione in 12 casi e amputazione in 3. Venti pazienti hanno sviluppato metastasi (14%), in un caso già presenti alla diagnosi. Le metastasi erano localizzate ai polmoni in 9 casi ed in sedi extrapolmonari in 11 casi. Al follow-up più recente l’80% dei pazienti era libero da malattia, l’8% era libero da malattia dopo escissione di RL o metastasi, il 2% era vivo con malattia, il 10% era deceduto per la malattia. 11 pazienti (5%) sono stati sottoposti ad amputazione, in un caso come prima procedura chirurgica, in 3 casi dopo RL e in 3 casi per complicazioni dovute alla radioterapia. La sopravvivenza a 5 e 10 anni è stata rispetti-vamente del 90% e 85%. La sopravvivenza libera da RL è stata dell’89% e 86% a 5 e 10 anni e la sopravvivenza libera da meta-stasi è stata del 85% e 81% a 5 e 10 anni. Abbiamo rilevato una differenza statisticamente significativa sia tra margini adeguati e inadeguati e RL (92% vs 82% a 5 anni; 86% vs 82% a 10 anni; P = 0,0457) che nello sviluppo di metastasi (94% vs 63% a 5 anni; 89% vs 63% a 10 anni; P=<0.0001).
Discussione: il trattamento multidisciplinare si è dimostrato efficace nel controllo locale e sistemico del MRCL. I margini chirurgici si sono rivelati l’unico fattore prognostico significativo sia per il controllo locale che sistemico.
Conclusioni: in oltre la metà dei casi le metastasi a distanza erano a localizzazione extra polmonare: questo dovrebbe essere tenuto in considerazione durante il follow-up
Surgical treatment of pathologic fractures of humerus
No full textThis study evaluates different operative treatment options for patients with metastatic fractures of the humerus focusing on surgical procedures, complications, function, and survival rate. From January 2003 to January 2008, 87 pathological fractures of the humerus in 85 cancer patients were surgically treated in our institutions. Histotypes were breast (n=21), lung (n=14), prostate (n=5), bladder (n=4), kidney (n=13), thyroid (n=7), larynx (n=1), lymphoma (n=5), myeloma (n=8), colon-rectum (n=1), melanoma (n=1), testicle (n=1), hepatocellular carcinoma (n=1) and unknown tumours (n=3). Lesions of the proximal epiphysis were treated with resection and endoprosthetic replacement (n=30). The remaining 57 fractures were stabilized with antegrade unreamed intra-medullary locked nailing without (9 cases) or with resection and use of cement (48 cases). The function of the upper limb was assessed using the Musculo-Skeletal Tumor Society (MSTS) rating scale and survival rate was retrospectively analysed. The mean survival time of patients after surgery was 8.3 months. Complications of endoprosthetic replacement recorded included disease relapse (n=3), soft tissue infection (n=2) and palsy of musculocutaneous nerve (n=1) whereas, for intra-medullary locked nailing there were three cases of soft tissue infection and one case of radial nerve palsy. The mean MSTS score at follow-up was 73% for endoprosthesis and 79.2% for locked intra-medullary nailing. Endoprosthetic replacement of the proximal humerus provides a good function of the upper limb, a low risk of local relapse with a low complication rate at follow-up. Unreamed nailing provides immediate stability and pain relief, minimum morbidity and early return of function
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
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