1,721,002 research outputs found
Combining molecular targeted agents with radiation therapy for malignant gliomas
No full textThe expansion in understanding the molecular biology that characterizes cancer cells has led to the rapid development of new agents to target important molecular pathways associated with aberrant activation or suppression of cellular signal transduction pathways involved in gliomagenesis, including epidermal growth factor receptor, vascular endothelial growth factor receptor, mammalian target of rapamycin, and integrins signaling pathways. The use of antiangiogenic agent bevacizumab, epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib, mammalian target of rapamycin inhibitors temsirolimus and everolimus, and integrin inhibitor cilengitide, in combination with radiation therapy, has been supported by encouraging preclinical data, resulting in a rapid translation into clinical trials. Currently, the majority of published clinical studies on the use of these agents in combination with radiation and cytotoxic therapies have shown only modest survival benefits at best. Tumor heterogeneity and genetic instability may, at least in part, explain the poor results observed with a single-target approach. Much remains to be learned regarding the optimal combination of targeted agents with conventional chemoradiation, including the use of multipathways-targeted therapies, the selection of patients who may benefit from combined treatments based on molecular biomarkers, and the verification of effective blockade of signaling pathways. © 2013 Scaringi et al
Technical advances in radiation therapy for brain tumors
No full textRadiation therapy plays a critical role in the management of brain tumors. Recent advances in radiation techniques include the use of intensity-modulated radiotherapy (IMRT), volumetric-modulated arc therapy (VMAT) and stereotactic radiosurgery (SRS). All of these techniques allow the delivery of higher radiation doses to the target volume, at the same time reducing the risk of toxicity to normal tissues as compared with conventional 3D conformal radiotherapy (3D-CRT). Proton therapy may represent a treatment alternative to photon irradiation, due to the more favorable dose distribution to the target volume. This review summarizes current developments in radiation therapy and their clinical impact on the management of patients with brain tumors
Temozolomide-related hematologic toxicity
No full textTemozolomide (TMZ) is an oral alkylating agent used for the treatment of recurrent or newly diagnosed malignant gliomas with significant survival benefit. TMZ is generally well tolerated and safe. The most common side effects are mild to moderate, and are represented by fatigue, nausea, vomiting, thrombocytopenia, and neutropenia. However severe hematologic adverse events (HAEs), including myelodysplastic syndrome and aplastic anemia, have also been reported. In this review we present an overview of the available literature of HAEs after exposure to TMZ. © 2013 S. Karger GmbH, Freiburg
Stereotactic irradiation of GH-secreting pituitary adenomas
No full textRadiotherapy (RT) is often employed in patients with acromegaly refractory to medical and/or surgical interventions in order to prevent tumour regrowth and normalize elevated GH and IGF-I levels. It achieves tumour control and hormone normalization up to 90 and 70 of patients at 10-15 years. Despite the excellent tumour control, conventional RT is associated with a potential risk of developing late toxicity, especially hypopituitarism, and its role in the management of patients with GH-secreting pituitary adenomas remains a matter of debate. Stereotactic techniques have been developed with the aim to deliver more localized irradiation and minimize the long-term consequences of treatment, while improving its efficacy. Stereotactic irradiation can be given in a single dose as stereotactic radiosurgery (SRS) or in multiple doses as fractionated stereotactic radiotherapy (FSRT). We have reviewed the recent published literature on stereotactic techniques for GH-secreting pituitary tumors with the aim to define the efficacy and potential adverse effects of each of these techniques. Copyright © 2012 G. Minniti et al
Stereotactic radiotherapy and radiosurgery for non-functioning and secreting pituitary adenomas
No full textRadiotherapy (RT) is frequently employed in patients with residual or recurrent pituitary adenoma with excellent rates of tumor control and remission of hormonal hypersecretion. Advances in RT have improved with the use of stereotactic techniques either as fractionated stereotactic radiotherapy (FSRT) or stereotactic radiosurgery (SRS), all aiming to improve the dose distribution to the tumor while reducing the amount of normal brain receiving significant doses of radiation. We provide an overview of the recent published literature on the long-term efficacy and adverse effects of stereotactic irradiation in nonfunctioning and secreting pituitary adenomas. Both techniques are associated with excellent clinical outcomes; however, advantages and drawbacks of each of these techniques in terms of local control, hormonal excess normalization, and radiation-induced toxicity remain a matter of debate. In clinical practice, single-fraction SRS may represent a convenient approach to patients with small and medium-sized pituitary adenoma away at least 2 mm from the optic chiasm, whereas FSRT is preferred over SRS for lesions >2.5–3 cm in size and/or involving the anterior optic pathway
Integrin inhibitor cilengitide for the treatment of glioblastoma: A brief overview of current clinical results
No full textGlioblastoma is the most frequent primary malignant brain tumor in adults. Postoperative radiotherapy (RT) with concomitant and adjuvant chemotherapy with temozolomide is the standard treatment, however the prognosis remains poor with a median survival in the range of 12-15 months. In recent years, several targeted agents have been developed as potential inhibitors of molecular genetic and signal transduction pathways involved in gliomatogenesis, including those of vascular endothelial growth factor and its receptor, epidermal growth factor receptor, integrin, and mammalian target of rapamycin. The integrins are a family of transmembrane glycoprotein receptors that mediate cell matrix and cell-cell interactions, and are widely expressed in glioma cells and tumor vasculature. The critical role of integrins in angiogenesis, cell invasion and migration make them an attractive target for anticancer therapy. Inhibitory peptides and monoclonal antibodies to integrins are currently being investigated in clinical trials in patients with solid tumors, such as colorectal cancer, renal cell carcinoma, and melanoma. Cilengitide, a cyclized Arg-Gly-Glu(RGD)- containing pentapeptide that selectively blocks activation of the αvβ3 and αvβ5 integrins has shown encouraging activity in patients with glioblastoma as single agent, and in association with standard RT and temozolomide. In this review, we provide a brief overview of the preclinical experience and current clinical results of cilengitide therapy in patients with recurrent or newly diagnosed glioblastoma
Reply to Zaragori et al.: “Is IDH mutation status associated with 18F-FDopa PET uptake”
No full textWe thank Zaragori et al. for reading and commenting on our article regarding the lack of correlation between 3,4‐dihydroxy‐6‐[18F]‐fluoro-L‐phenylalanine (F-DOPA) uptake parameters and IDH mutation status and 1p/19q co-deletion in glioma. These authors had initially suggested that the presence of IDH mutation is associated with higher F-DOPA uptake in a cohort of diffuse grade II and grade III gliomas. In a later study comprising a mixed population of 58 newly diagnosed glioma and glioblastoma patients, the same group did not confirm their previous observation, showing similar static F-DOPA uptake parameters between tumors with different molecular marker
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
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