442 research outputs found

    Sinonasal Malignancies and Charged Particle Radiation Treatment: A Systematic Literature Review

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    Background. Paranasal and nasal cavity malignancies are rare tumors that frequently present at advanced stages. Tumor extension and anatomic complexity pose a challenge for their treatment. Due to their peculiar physical and biological properties particle radiation therapy, i.e. protons and ions can have a role in their management. We performed a systematic literature review to gather clinical evidence about their use to treat sinonasal malignancies. Materials and Methods. We searched the browsers PubMed and Medline as well as specific journals and conference proceedings. Inclusion criteria were: at least 10 patients, English language, reporting outcome and/or toxicity data. Results. We found six studies with data on clinical outcome. Carbon and helium ions were each used in one study, protons in four. Toxicity was specifically described in five studies. One reported acute toxicity of carbon ions, one dealt with brain toxicity from both carbon ions and protons. Three papers reported on visual toxicity: one from carbon ions, one from protons and one from both. Specific data were extracted and compared with the most pertinent literature. Conclusion. Particle radiation therapy is in its early phase of development. Promising results achieved so far must be confirmed in further studies

    Radiotherapy after Conservative Surgery in Ductal Carcinoma In Situ of the Breast: A Review

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    Several large prospective and retrospective studies have demonstrated excellent long-term outcomes after breast conservative treatment with radiation in invasive breast cancer. Breast-conserving surgery (BCS) followed by radiotherapy (RT) is an accepted management strategy for patients with DCIS. Adding radiation treatment after conservative surgery enables to reduce, without any significant risks, the rate of local recurrence (LR) by approximately 50% in retrospective and randomized clinical trials. As about 50% of LRs are invasive and have a negative psychological impact, minimizing recurrence is important. Local and local-regional recurrences after initial breast conservation treatment with radiation can be salvaged with high rates of survival and freedom from distant metastases

    Numerical Simulation of the Medical Linear Accelerator Electron Beams Absorption by ABS-Plastic doped with Metal

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    In this paper the numerical simulation results of the dose spatial distribution of the medical electron beams in ABS-plastic doped with different concentrations of lead and zinc are shown. The dependences of the test material density on the lead and zinc mass concentrations are illustrated. The depth dose distributions of the medical electron beams in the modified ABS-plastic for three energies 6 MeV, 12 MeV and 20 MeV are tested. The electron beam shapes in the transverse plane in ABS-plastic doped with different concentrations of lead and zinc are presented

    Report of long-term follow-up in a randomized trial comparing radiation therapy and radiation therapy plus hyperthermia to metastatic lymphnodes in stage IV head and neck patients

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    Purpose: The treatment of inoperable metastatic lymphnodes in patients with head and neck cancer represents a therapeutic challenge. Clinical results using conventional radiation therapy are disappointing; on the other hand, the evaluation of recent innovative radiotherapeutic methods is still pending. The end points of this analysis were focused on long-term local control, on its potential influence on survival, and on late toxicity of a previously reported randomized Phase III study comparing conventionally fractionated radical irradiation alone or combined with local hyperthermia in fixed and inoperable metastatic neck lymphnodes. Methods and Materials: The medical records of 41 patients (44 nodes) with advanced locoregional Stage IV squamous cell cancer of the head and neck and randomized to treatment in the period 1985-1986 with irradiation alone ( 22 23 evaluable nodes) or combined with external hyperthermia ( 18 21 evaluable nodes), were re-evaluated. Results: The statistically significant difference observed in "early" response (p = 0.0164) in favor of the combined treatment results in improved 5-year actuarial nodal control (p = 0.015). Clinical improvement noted in tumor control positively affects survival, leading to a statistically significant difference in survival at 5 years (p = 0.02). With respect to side effects, no clearly enhanced acute or late toxicity has been found; as severe late effects, two patients with bone necroses possibly related to the combined treatment have been observed. Thermal analysis failed to show a significant correlation between heating parameters and the end points of the study. Conclusion: This report with 5-year follow-up confirms the efficacy and the absence of severe toxicity of the combination of radical radiation and hyperthermia in the treatment of metastatic lymphnodes in Stage IV squamous cell carcinoma of the head and neck

    Heteronormatividad, autoestima y bullying homofóbico en Argentina

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    El presente trabajo tuvo como objetivo principal analizar, desde una perspectiva de géneros, el bullying homofóbico y su repercusión en la autoestima de aquellos sujetos de identidades y orientaciones sexuales no heteronormativas. Para lo mismo, se encuestó mediante la utilización del Google Forms, a 220 adultos/as que se escolarizaron en Argentina y que respondieron en base a sus experiencias de escolarización pasada. De esta forma, se relevaron distintos tipos de acoso escolar a personas LGBTIQ y diferentes formas de reacción de las mismas frente a otras situaciones de acoso. Finalmente, se dio cuenta de la variación de la autoestima en las personas víctimas de bullying homofóbico y de la relación entre el acoso recibido, y la adopción de un rol de observador activo frente a otras situaciones de igual carácter.    </p

    Combinatorial optimisation in radiotherapy treatment planning

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    The goal of radiotherapy is to cover a target area with a desired radiation dose while keeping the exposition of non-target areas as low as possible in order to reduce radiation side effects. In the case of Intensity Modulated Proton Therapy (IMPT), the dose distribution is typically designed via a treatment planning optimisation process based on classical optimisation algorithms on some objective functions. We investigate the planning optimisation problem under the point of view of the Theory of Complexity in general and, in particular, of the Combinatorial Optimisation Theory. We firstly give a formal definition of a simplified version of the problem that is in the complexity class NPO. We prove that above version is computationally hard, i.e. it belongs to the class NPO\PTAS if NP not equal P. We show how Combinatorial Optimisation Theory can give valuable tools, both conceptual and practical, in treatment plan definition, opening the way for new deterministic algorithms with bounded time complexity which have to support the technological evolution up to adaptive plans exploiting near real time solutions

    Metastatic Thymoma of the Breast

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    Breast metastasis from nonmammary malignant neoplasms is uncommon, and it accounts for approximately 2% of all breast tumors. Distant metastasis of thymoma is very rare, and especially to extrathorcic areas. We report a female who had a metastatic thymoma in her breast 20 years after undergoing resection for a non-invasive thymoma. She presented with a palpable mass in her left breast. Mammography and ultrasonogram showed a lobular mass at the anterior glandular portion. Histological examination after surgical excision revealed a metastatic thymoma
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