[en] A patient quality assurance program should be performed in IMRT treatments in order to check if computed dose matches to delivered dose. Many different devices for verification are used, such as radiographic film, radiochromic film, detector arrays or electronical portal imaging devices (EPID). The aim of this study was to introduce a new portal dose prediction method based on a superposition algorithm available in a treatment planning system (CMS XiO), considering the EPID as a phantom. Two Varian 21EX linacs equipped with amorphous silicon EPID were available. EPID were calibrated according to manufacturers procedure, so that pixel number could be read as dose values. The EPIDs were dismounted from the Exact-arm positioning device and CT images were taken. Using these CT slices, map doses were computed on the EPID imaging plane with superposition algorithm. Some tests were made to compare computed dose maps versus portal dose images by gamma index evaluation, including prostate and head and neck IMRT cases, showing a good agreement. In this method, the same energy model for the planning system was used both in the dose prediction and the treatment plan. (Author) 22 refs.

[en] In certain conditions, the welding of SA-182 (F-317L) stainless steel welded forged flanges can give rise to the appearance of lamellar tearing. The usual reception tests do not allow to detect in advance this problem, which appears during the fabrication stage. To avoid the problem it would be necessary to carry out the final heat treatments of the flanges at a temperature higher than the one included in the corresponding standard. On the other hand, and for certain conditions, the corrosion behaviour of the material might not be the proper one. (Author) 9 refs

[en] Colloid cysts (CC) are uncommon cystic endo dermal tumors located in the roof of the third ventricle. The clinical features depend on their capacity for obstructing the foramen of Monro, which results in univentricular or biventricular hydrocephalus. We present three cases of colloid cysts of the third ventricle, diagnosed by CT, reviewing their diagnostic, clinical and pathological features

[en] Historically, stereotactic radiosurgery has been associated with invasive fixation systems-location guarantee that sub-millimeter accuracy to deliver high radiation doses to small volumes. The development of noninvasive stereotactic systems (no frame) allow for greater patient comfort without compromising accuracy. System availability BrainLAB for frame less cranial arteriovenous malformations (AVM) is relatively recent. It discusses the preliminary results of the positioning accuracy of AVM patients treated with the frame less system.

[en] The CT and MR findings are reported for a patient diagnosed as having teratoma of the posterior fossa with onset in the form of intracranial hypertension. The objective of this article is to report the detection of the lesion, as well as its origin in the closure defect of the cranial cavity with the formation of a cutaneous fistula, and review the recent literature

[en] The Ct and MR findings are presented for two patients previously diagnosed as having cerebral arteriovenous malformations (AVM), treated by means of stereotaxic radiosurgery. The study of their course following corticosteroid therapy is also reported. The diagnosis was based on changes in the MR signal and density on CT and on their late onset, and was confirmed by puncture. The good clinical and radiological course is discussed. (Author) 10 refs

[en] The cerebral cavernous angioma (CA) is included in the group of cerebral malformations that can not be detected angiographically. We present the retrospective study of 16 patients, diagnosed as having CA, comparing the data provided by CT and MR, as well as the contribution of cerebral angiography. (Author) 25 refs

[en] Zirconium treated graphite tubes were investigated and compared with non-treated and palladium coated ones for in situ trapping of selenium hydride generated in a flow injection system. Selenium was effectively trapped on zirconium treated tubes at trapping temperatures of 300-600C, similar to those observed for palladium, whereas trapping temperatures higher than 600C had to be used with non-treated tubes. Zirconium treated tubes used in this work showed good stability up to 300 trapping/atomization cycles, with precision better than 5%, characteristic masses of 42 (peak height) and 133 pg (peak area) of selenium were obtained. Sensitivity of zirconium and palladium treatments were similar, but zirconium offered the advantage of a single application per tube. Detection limits were 0.11 (peak height) and 0.23 ng (peak area) for a 1 ml sample volume. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

[en] Highlights: • Development and qualification of a dimensional metrology procedure on wound superconductor trajectory based on Laser scanning system. • Dimensional control of the conductor centreline during winding, before and after heat treatment. • Radial Plate groove centreline length controlled using Laser Trackers. • Full scale wound Double Pancake prototype transferred inside Radial Plate prototype without any issues. - Abstract: The ITER Toroidal Field (TF) magnet system consists of 18 “D” shaped coils. Fusion for Energy (F4E), the European Domestic Agency for ITER, is responsible for the supply of 10 out the 19 TF coils (18 installed plus one spare coil). Each TF coil, about 300 t in weight, is made of a stainless steel case containing a Winding Pack (WP). The European manufacturing of the Radial Plates (RPs) and WPs has been awarded to two different industrial partners, whose activities are strongly linked with each other. In order to manufacture a Double Pancake (DP), first, the conductor has to be bent onto a D-shaped double spiral trajectory, then heat treated and inserted in the grooves of the RP. This represents the most challenging manufacturing step: in order to fit inside the groove, the double spiral trajectory of the conductor must match almost perfectly the trajectory of the groove, over a length above 700 m. In order to achieve this, the conductor trajectory length must be controlled with an accuracy of 1 mm over a length of 350 m while the radial plate groove has to be machined with tolerances of ±0.2 mm over dimensions of more than 10 m. In order to succeed, it has been essential to develop a metrology process capable to control with high accuracy both the DP conductor and the RP groove trajectories. This paper reports on the work carried out on the development and qualification of the dimensional metrology to monitor the manufacturing of the conductor. Reference is made to the final dimensional check of the RP focusing on the groove centreline length. In addition the results obtained on the one to one scaled prototype DP are described. Finally, the strategy and foreseen improvements for the production of DPs are discussed.