[en] The CyberKnife VSI system has the ability to carry out treatments for injuries that move with respiration through tracking Synchrony system, compensating for the breathing of the patient through the robotic arm, and thus allowing the reduction of the volume of treatment PTV margins. Tumor tracking is based on a model of correspondence between the positions of internal fiduciales brands previously introduced in the patient, and the external positions of infrared transmitters placed on the patient. This model is associated with a few errors that should be taken into account. The objective of the study is twofold: on the one hand to study the movement of the PTV based on location, and on the other analyze errors associated with this respiratory model. (Author)

[en] The objective of this study is to analyze the results, as well as their temporal evolution in time of unit operation. (Author)

[en] Cardiac Multislice Computed Tomography (MSCT) is mainly used for the quantification of coronary artery calcification and for minimally invasive coronary angiography. Many physicians are not aware of the radiation doses delivered to the patient in these exams. The aim of this study is to evaluate and compare the radiation doses that are delivered to the patient during specific cardiac MSCT examinations in two different hospitals in Madrid. The volume computed tomographic dose index (CTDI vol), the dose length product (DLP), and the effective dose (E) are the most useful parameters to describe and compare radiation doses received from cardiac MSCT examinations. To calculate effective doses the spreadsheet developed by ImPACT was used. Computed tomography dose index (CTDIn) in air was measured with an ionization chamber model 20x5-2CT and dose-length product (DLP) values were obtained from the scanner consol for each examination. Results and conclusions: Effective dose values of 18,2 mSv and 24 mSv for coronary angiography were found in the two hospitals. The difference in dose is mainly due to the different mode of acquisition in the applied protocols rather than to the type of scanner used. (Author)

[en] Introduction The second class Radioactive Installation start -up authorization makes responsible for its security to the installation exploiter and supervisor. The specifications established in the authorization, which are mandatory, point out several actions, some of these actions are the hermeticity tests of radioactive sources an radiologic controls of environment dosimetry. It is necessary to optimize the time spent in each activity, managing them as reasonably as possible. An important matter to take into account is to keep and control only those radioactive or radiological equipment which, even if are in work, have an appropriate performance for the patient treatment Material And Method a Paz hospital has an intracavity brachytherapy (L.D.R.), Curietron model. The Radioprotection Department proposed to remove from service the unit due to its age, this was carried out by the Commission of Guarantee and Quality Control. There were different solutions taken into account to decommission the unit, finally the option chosen as the most convenient for the installation was to manage directly the withdrawal of the radioactive material which consisted of seven Cs-137 probes model CsM1 and total nominal certificated activity of 7770 MBq ( 210 mCi ) dated in May 2005. It also has to be considered as a radioactive waste the inner storage elements of the Curietron and the transport and storage curie stock, built with depleted uranium. To accomplish this aim an evacuation container was designed consisting of an alloy of low-melting point (M.C.P.96), which fulfills the transport conditions imposed by E.N.R.E.S.A. ( Empresa Nacional de Residuos Radiactivos, S.A). A theoretical calculation was performed to estimate the thickness of the shield which adequate to the rate of dose in contact demanded. Accuracy of these calculations has been verified using T.L. dosimetry. Results The radiation levels during the extraction intervention of the radioactive probes and its transfer to the evacuation container, with the seven probes in their plastic stands, reach 2.5 mSv/h at a distance of 50 cm. The TLD dosimetry performed on the top of the container has an average value of 1,11 mSv/h in contact. The theoretical calculation shows 1.6 mSv/h. We understand that the difference is due to the formalism used in the calculation of the building factor. Conclusion Removing from service encapsulated sources as a solid radioactive waste can be performed in an easy way from the Radioprotection Department. The theoretical calculation of the evacuation container has been compared to experimental T.L. measurements to prove the rate of equivalent dose levels demanded by E.N.R.E.S.A.. The comparison of the economic evaluation of several procedures supports the election made in the management of the evacuation process. (authors)

[en] Full text of publication follows: Purpose: The purpose of this study is to analyze the current situation of an Interventional Radiology installation. A retrospective study of the doses received by interventional radiology specialists was carried out in order to optimize the radiologic protection activities. Material And Methods: Interventional Radiology is a speciality in which staff involved can be exposed to significant occupational radiation risks. The dosimetric data gathered since the incorporation date in the installation of three interventional radiologists are reported. Relations between doses and workload are studied. A retrospective estimation of effective doses and dose to lens was performed using dosimetric records. The variety of interventional procedures are analyzed in order to determine if radiation protection activities has been taken to minimize risk, and the benefits of carrying out these activities are also evaluated. Results And Conclusions: The workload increase and different activity of the three radiologists has derived in an occupational dose increase. Training and quality assurance are indispensable in interventional radiology to minimize occupational risk. (authors)

[en] The present study summarizes preliminary data addressed to complete the present knowledge on the microwave (M.V.)-exposure doses and conditions in workers exposed chronically to relatively high, though nonthermal, levels of that non ionizing radiations (N.I.R.). The obtained data are of direct application to radiation protection in occupational media provided that: 1) help to detect and eradicate practices and situations that result in overexposure; 2) they constitute a basis for the design and development of strategies for exposure control and minimization, and 3) they represent a dosimetric support necessary to properly interpret past and future epidemiologic and experimental data on potential health effects of chronic exposures to M.W. radiation at work. The described results will be extended through additional dosimetric recordings in other hospitals. The dosimetric data will be compared to the results of questionnaires among the electro-therapists working at the units studied. The objective is to identify potential relationships between exposure doses and specific diseases or level of risk perception among the investigated professional group. (authors)