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Search Results: 1 - 10 of 22404 matches for " Roberto Orecchia "
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Heating cancer stem cells to reduce tumor relapse
Pier Pelicci, Paola Dalton, Roberto Orecchia
Breast Cancer Research , 2011, DOI: 10.1186/bcr2847
Abstract: According to the cancer stem cell (CSC) hypothesis [1,2], tumorigenicity, the capacity to propagate a tumor, is not an intrinsic property of any tumor cell, but the defining function of a specialized cell-type, the CSC. Within individual tumors, only CSCs are able to reform a tumor after transplantion in mouse recipients. Notably, these tumors have the same cellular heterogeneity as the initial one, including both tumorigenic (CSCs) and non-tumorigenic cells (the remaining cells). CSCs express some surface markers of the corresponding normal tissue stem cells, while the non-tumorigenic remaining cells express markers of progenitors or more differentiated cells.The existence of a cell hierarchy within tumors is shown by CSCs' ability to reform biologically hetero-geneous tumors also from single-cell transplantation, whereby a CSC generates, through a single asymmetric mitotic division, phenocopies of itself (self-renewal) and differentiated/non-tumorigenic tumor cells [3].While the CSC theory lacks definitive proof, it bears important implications for cancer treatment. Anti-cancer drugs have been selected in early clinical trials for their property to reduce tumor size, an effect that reflects their ability to kill the bulk of tumor cells, but not necessarily the rare CSCs. These might then become the cellular base of clinical relapse.Drugs capable of reducing tumor size and producing clinical remission are available for many tumor types. Nonetheless, tumors eventually relapse in a large proportion of cases, even after long intervals. For instance, in mammary tumors relapse rate after chemotherapy and/or radiotherapy remains very high (up to approximately 50%) and may occur as late as 30 years after manifestation of disease. Thus, the initial treatment might have spared a small population of cells with the ability to survive for long periods of time and to re-initiate tumor growth; cells that, according to the CSC theory, would be, by definition, CSCs. Stem cells are
Partial breast irradiation and intraoperative radiotherapy
R Orecchia
Breast Cancer Research , 2007, DOI: 10.1186/bcr1694
Abstract: PBI allows reducing the radiation field to only the initially involved quadrant of the breast and significantly shortens the duration of radiation therapy. This may represent the possibility of overcoming constraints such as accessibility to the radiation therapy centres, and the socioeconomic impact on the working life and on the personal habits of the patient. PBI seems to have a positive impact on patients' quality of life. Another important advantage is the avoidance of interactions with systemic therapy that may determine delays in the initiation or in the carrying out of the conventional treatment.These possible benefits must be balanced with the potential risk of recurrence within the untreated tissue in the breast receiving PBI as well as the unknown long-term cosmetic results with the accelerated techniques. Significant practical considerations also include the choice of technique, interstitial brachytherapy (high dose-rate versus low dose-rate), balloon-based brachytherapy (MammoSite?), external beam (3D-conformal versus intensity modulated radiation therapy), and intra-operative irradiation (electrons versus low-energy X-ray device). The choice of the technique has an impact on the schedules and dose-rate that can be used, on the volume that can be irradiated and on the dose homogeneity achievable.Patient selection also remains uncertain, including questions regarding age exclusions, applicability with various primary tumour sizes, hystopathological features, the tumour-free margin and amount of tumour near the margins, and negative (including micrometastasis) or positive axillary lymph node status (up to three or more).For this reason, data coming from the multicentric or unicentric large phase III ongoing trials in the United States and Europe comparing standard irradiation with the different PBI schedules and techniques will hopefully support the movement of PBI into routine clinical practice. Issues of patient selection, target volume definition, tota
Points in generic position and conductor of varieties with ordinary multiple subvarieties of codimension one
Ferruccio Orecchia
Mathematics , 1998,
Abstract: We extend results of our previous papers, on ordinary multiple points of curves, and on the computation of their conductor, to ordinary multiple subvarieties of codimension one.
Ordinary Subvarieties of codimension one
Ferruccio Orecchia
Mathematics , 1998,
Abstract: In this paper we extend the properties of ordinary points of curves [10] to ordinary closed points of one-dimensional affine reduced schemes and then to ordinary subvarieties of codimension one.
A new option for early breast cancer patients previously irradiated for Hodgkin's disease: intraoperative radiotherapy with electrons (ELIOT)
Mattia Intra, Oreste Gentilini, Paolo Veronesi, Mario Ciocca, Alberto Luini, Roberta Lazzari, Javier Soteldo, Gabriel Farante, Roberto Orecchia, Umberto Veronesi
Breast Cancer Research , 2005, DOI: 10.1186/bcr1310
Abstract: Six patients affected by early breast cancer previously treated with mantle radiation for HD underwent BCS associated with full-dose intraoperative radiotherapy with electrons (ELIOT).A total dose of 21 Gy (prescribed at 90% isodose) in five cases and 17 Gy (at 100% isodose) in one case were delivered directly to the mammary gland without acute complications and with good cosmetic results. After an average of 30.8 months of follow up, no late sequelae were observed and the patients are free of disease.In patients previously irradiated for HD, ELIOT can avoid repeat irradiation of the whole breast, permit BCS and decrease the number of avoidable mastectomies.The risk of developing breast cancer after radiotherapy for Hodgkin's disease (HD) is well documented and is attributed to the incidental inclusion of portions of the breast in the portals used to irradiate the mediastinum with or without infraclavicular/axillary regions [1,2]. This increased risk depends on several patient and treatment factors, including radiation dose, radiation treatment field and age at treatment [3]. The estimated risk is also affected by the duration of follow up after radiotherapy and the method used to calculate risk [4]. Based on concern about possible severe sequelae arising after a high total cumulative dose to the breast, several authors [5,6] have suggested mastectomy as the treatment of choice for breast cancer arising after radiotherapy for HD.Few studies have been published whereby alternative therapies to mastectomy have been employed; they describe local excision alone, or interstitial brachytherapy and local excision followed by local field external beam radiotherapy [7-10].In order to avoid a dangerously high total cumulative dose of radiotherapy to the whole breast, soft tissues of the thoracic wall, lung and heart, without rejecting the possibility of breast conserving surgery (BCS), we evaluated the potential of performing full-dose intraoperative radiotherapy with electro
Intra-fraction setup variability: IR optical localization vs. X-ray imaging in a hypofractionated patient population
Maria Spadea, Barbara Tagaste, Marco Riboldi, Eleonora Preve, Daniela Alterio, Gaia Piperno, Cristina Garibaldi, Roberto Orecchia, Antonio Pedotti, Guido Baroni
Radiation Oncology , 2011, DOI: 10.1186/1748-717x-6-38
Abstract: We analyzed data coming from 87 patients treated with hypo-fractionated radiotherapy at cranial and extra-cranial sites. Patient setup was realized through the ExacTrac X-ray 6D system (BrainLAB, Germany), consisting of 2 infrared TV cameras for external fiducial localization and X-ray imaging in double projection for image registration. Before irradiation, patients were pre-aligned relying on optical marker localization. Patient position was refined through the automatic matching of X-ray images to digitally reconstructed radiographs, providing 6 corrective parameters that were automatically applied using a robotic couch. Infrared patient localization and X-ray imaging were performed at the end of treatment, thus providing independent measures of intra-fraction motion.According to optical measurements, the size of intra-fraction motion was (median ± quartile) 0.3 ± 0.3 mm, 0.6 ± 0.6 mm, 0.7 ± 0.6 mm for cranial, abdominal and lung patients, respectively. X-ray image registration estimated larger intra-fraction motion, equal to 0.9 ± 0.8 mm, 1.3 ± 1.2 mm, 1.8 ± 2.2 mm, correspondingly.Optical tracking highlighted negligible intra-fraction motion at both cranial and extra-cranial sites. The larger motion detected by X-ray image registration showed significant inter-patient variability, in contrast to infrared optical tracking measurement. Infrared localization is put forward as the optimal strategy to monitor intra-fraction motion, featuring robustness, flexibility and less invasivity with respect to X-ray based techniques.Over the last few years, the development of Image Guided Radiation Therapy (IGRT) technologies has resulted in the design and realization of systems allowing precise patient setup and monitoring at each therapy fraction [1-3]. The rationale is related to dose escalation and hypo-fractionated protocols, which require the precise localization of the target throughout the treatment. Morphological changes, tumor shrinkage and organ motion effects lead
Retratos ficcionales en la narrativa de Ricardo Piglia : variaciones sobre el retrato del (autor en) artista
Teresa Orecchia-Havas
Cuadernos LIRICO : Revista de la Red Interuniversitaria de Estudios sobre las Literaturas Rioplatenses Contemporáneas en Francia , 2006,
Abstract: Biografía y ficciónUna de las formas frecuentes de la presencia de la figura del autor empírico en la literatura contemporánea es la incorporación de datos biográficos en el texto, datos que pasan a formar parte del discurso ficcional sin perder la seducción de aquello que se asoma como asunto ligado al sujeto histórico que es el escritor e incluso, como material eventualmente verificable. En el caso de la obra de Piglia, lo (auto)biográfico no se inscribe nunca como totalidad (como verdad), ...
Concurrent cisplatin, continuous infusion fluorouracil and radiotherapy followed by tailored consolidation treatment in non metastatic anal squamous cell carcinoma
Maria G Zampino, Elena Magni, Maria C Leonardi, Luigi Santoro, Elena Petazzi, Cristiana Fodor, Giuseppe Petralia, Cristina Trovato, Franco Nolè, Roberto Orecchia
BMC Cancer , 2011, DOI: 10.1186/1471-2407-11-55
Abstract: TNM staged anal squamous-cell cancer patients were treated with pelvic radiotherapy concomitant to continuous infusion fluorouracil plus cisplatin for at least 2 cycles. In T3-T4 or any T - N+ tumours or in "slow-responder" cases, 1-2 chemotherapy courses were subsequently administered. Tumour assessment was performed at baseline and 6-8 weeks after radiotherapy to evaluate response.29 patients were enrolled: 4 males, 25 females; median age 57 years; baseline T1/T2/T3/T4 2/12/7/8; N involvement 17. Median dose pelvic radiotherapy was 59.4 Gy (range: 54-74). In 5 patients 2 chemotherapy courses, in 12 patients three and in 12 patients four courses were performed. At first evaluation, 27 CR (93.1%; 95% CI: 78% - 98%) and 2 SD were observed. Main grade (G) 3 toxic events were neutropenia (8%), diarrhoea (8%) and dermatitis (62%). Most frequent late events G3-G4 occurred in 14 patients: proctitis (5), dermatitis (4), bladder dysfunctions (2), sexual dysfunctions (9), lower extremity venous thromboses (2), dysuria (1), stenosis (1) and tenesmus (1). Five patients reported G1 leucopoenia. The rate of colostomy was 14%. After a median follow up of 42 months (range: 4-81), 20 patients are still alive without relapse and 3 died due to PD. The estimated 7-year DFS was 83.4% (C.I.: 68.3%-98.5%) and the estimated 7-year OS was 85.7% (C.I.: 70% - 100%). The 1-year and the estimated 7-year colostomy-free survivals were 85.9% (C.I.: 73.1% - 98.7%).Concurrent cisplatin plus fluorouracil and radiotherapy is associated with favourable local control rates and acute toxicity. Future investigations will be directed towards research into molecular biomarkers related to disease progression and resistance to chemo-radiotherapy and to the evaluation of new cytotoxic agents or targeted drugs, such as anti-epidermal growth factor receptor, concomitant to RT and to determining the role of intensity-modulated radiotherapy.Anal carcinoma is an uncommon disease that represents approximately 1% of
Surgical outcomes for colon and rectal cancer over a decade: results from a consecutive monocentric experience in 902 unselected patients
Bruno Andreoni, Antonio Chiappa, Emilio Bertani, Massimo Bellomi, Roberto Orecchia, MariaGiulia Zampino, Nicola Fazio, Marco Venturino, Franco Orsi, Angelica Sonzogni, Ugo Pace, Lorenzo Monfardini
World Journal of Surgical Oncology , 2007, DOI: 10.1186/1477-7819-5-73
Abstract: A consecutive series of 902 primary colorectal cancer patients (489 M, 413 F; mean age: 63 years ± 11 years, range: 24–88 years) was evaluated and prospectively followed in a university hospital (mean follow-up 36 ± 24 months; range: 3–108 months). Perioperative mortality, morbidity, overall survival, curative resection rates, recurrence rates were analysed.Of the total, 476 colorectal cancers were localized to the colon (CC, 53%), 406 to the rectum (RC, 45%), 12 (1%) were multicentric, and 8 were identified as part of HNPCC (1%). Combining all tumours, there were 186 cancers (20.6%) defined as UICC stage I, 235 (26.1%) stage II, 270 (29.9%) stage III and 187 (20.6%) stage IV cases. Twenty-four (2.7%) cases were of undetermined stage. Postoperative complications occurred in 38% of the total group (37.8% of CC cases, 37.2% of the RC group, 66.7% of the synchronous cancer patients and 50% of those with HNPCC, p = 0.19) Mortality rate was 0.8%, (1.3% for colon cancer, 0% for rectal cancer; p = 0.023). Multivisceral resection was performed in 14.3% of cases. Disease-free survival in cases resected for cure was 73% at 5-years and 72% at 8 years. The 5- and 8-year overall survival rates were 71% and 61% respectively (total cases). At 5-year analysis, overall survival rates are 97% for stage I disease, 87% for stage II, 73% for stage III and 22% for stage IV respectively (p < 0.0001). The 5-year overall survival rates showed a marked difference in R0, R1+R2 and non resected patients (82%, 35% and 0% respectively, p < 0.0001). On multivariate analysis, resection for cure and stage at presentation but not tumour site (colon vs. rectum) were independent variables for overall survival (p < 0.0001).A prospective, uniform follow-up policy used in a single institution over the last decade provides evidence of quality assurance in colorectal cancer surgery with high rates of resection for cure where only stage at presentation functions as an independent variable for cancer-related
Flow-Based Algorithms for Local Graph Clustering
Lorenzo Orecchia,Zeyuan Allen Zhu
Computer Science , 2013, DOI: 10.1137/1.9781611973402.94
Abstract: Given a subset S of vertices of an undirected graph G, the cut-improvement problem asks us to find a subset S that is similar to A but has smaller conductance. A very elegant algorithm for this problem has been given by Andersen and Lang [AL08] and requires solving a small number of single-commodity maximum flow computations over the whole graph G. In this paper, we introduce LocalImprove, the first cut-improvement algorithm that is local, i.e. that runs in time dependent on the size of the input set A rather than on the size of the entire graph. Moreover, LocalImprove achieves this local behaviour while essentially matching the same theoretical guarantee as the global algorithm of Andersen and Lang. The main application of LocalImprove is to the design of better local-graph-partitioning algorithms. All previously known local algorithms for graph partitioning are random-walk based and can only guarantee an output conductance of O(\sqrt{OPT}) when the target set has conductance OPT \in [0,1]. Very recently, Zhu, Lattanzi and Mirrokni [ZLM13] improved this to O(OPT / \sqrt{CONN}) where the internal connectivity parameter CONN \in [0,1] is defined as the reciprocal of the mixing time of the random walk over the graph induced by the target set. In this work, we show how to use LocalImprove to obtain a constant approximation O(OPT) as long as CONN/OPT = Omega(1). This yields the first flow-based algorithm. Moreover, its performance strictly outperforms the ones based on random walks and surprisingly matches that of the best known global algorithm, which is SDP-based, in this parameter regime [MMV12]. Finally, our results show that spectral methods are not the only viable approach to the construction of local graph partitioning algorithm and open door to the study of algorithms with even better approximation and locality guarantees.
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