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Biomedical subjects

L Conte

Publications and source records attributed to L Conte.

82 records · Page 5Linked to original sources
PubMedDate not supplied

Radiotherapy treatment verification.

During a radiotherapy treatment, a dosimetric verification or a geometric localization can be done, in order to assess the quality of the treatment. The dosimetric verification is generally performed measuring the dose at some points inside (natural cavities) or outside the patient, and comparing it to the dose at the same points calculated and predicted by the treatment planning system. This can be done either with thermoluminescent or diodes dosimeters or with ionization chambers. The geometric localization can be done acquiring a portal image of the patient. Portal imaging can be performed either with films placed between metallic screens, or with an electronic portal imaging device such as fluoroscopic systems, solid state devices or matrix ionization chamber systems. In order to assess possible field placement errors, the portal images have to be compared with images obtained with the simulator in the same geometric conditions and/or with the digitally reconstructed radiograph (DRR) obtained with the treatment planning system. In particular, when using matrix ionization chamber systems, the portal images contain also information regarding the exit dose. This means that this kind of imaging device can be used both for geometric localization and for dosimetric verification. In this case, the exit dose measured by the portal image can be compared with the exit dose calculated and predicted by the treatment planning system. Some "in-vivo" applications of this methodology are presented.

Humans↗
PubMedDate not supplied

Detection of hazelnut oil in virgin olive oil by assessment of free sterols and triacylglycerols.

Free sterols were evaluated as factors for discriminating between genuine virgin olive oil and hazelnut-mixed virgin olive oil. Numeric analyses of the results amplified the differences between groups. The application of this method to virgin olive oil samples and their mixtures with 10% hazelnut oil distinguished between genuine and nongenuine virgin olive oil with statistical certainty. Triacylglycerol analysis was tested for the same purpose by using parameter deltaECN42, but although it possessed a discriminating capacity, it alone could not distinguish the aforementioned groups with sufficient certainty. Free delta7-sterols data were combined with deltaECN42 data into a single discriminating function to improve differentiation and bring more ruggedness, and for detection of low amounts (10%) of hazelnut oil in virgin olive oil. In fact, the values obtained by addition of delta7-sterol data and deltaECN42 data showed a higher discriminating capacity than single parameters. In a single operation the method produced all the oil fractions necessary for analysis of free sterols and triacylglycerols with ECN42. Solid-phase extraction was applied in substitution of traditional chromatography on a silica column.

Chromatography, Gas↗
PubMedDate not supplied

[Traumatic lesions of the pancreas: diagnosis and treatment].

The diagnosis and treatment of traumatic lesions of the pancreas are difficult. The deep anatomical location of the organ, the lack of truly accurate non-invasive diagnostic investigations and the frequent initial scarcity or absence of specific symptoms, often mean that a clinical assumption based on the dynamics of the trauma is fundamental for a rapid, correct diagnosis. The state of the main pancreatic duct is the most important element in establishing the prognosis and guiding the treatment, and should therefore be accurately defined before or during surgery. If the Wirsung duct is intact, even when radiological, clinical and laboratory signs indicate a pancreatic lesion, conservative treatment can be attempted. On the contrary, if there is evidence of a lesion of the duct, surgery is mandatory, bearing in mind that pancreatic resections involving removal of the portion of the gland distal to the lesion have a lower incidence of complications than do reconstructive and/or anastomotic procedures and are therefore to be preferred. Nevertheless, in selected cases, especially in young patients, Roux-en-Y pancreaticojejunostomy can avoid the risk of functional insufficiency, sparing large tracts of otherwise sacrificed glandular tissue. Only the more serious complex lesions of the head of the pancreas also affecting the duodenum require pancreaticoduodenectomy.

Adolescent↗
PubMedDate not supplied

[Management of electron accelerators for radiotherapy. Data as of 31 December 1984].

Several italian radiotherapeutic centers have supplied the data analysed, regarding problems connected with the management of electron accelerators in the years 1982-1983-1984. The data concern 27 out of the 35 accelerators settled in Italy. The average cost of purchase has proved to be of 940 M pounds with an expense of annual allowance of 94 M pounds. We have then analysed the incidences of the allowance of the purchase expenditure of the machine (23%), the allowance of the expenses for the construction of the bunker (22%), the expenses of maintenance of the machine (5%), the cost of the staff (48%) and the cost of the power supply (2%) on the management costs (about pounds 820.000 per each handled patient). The duration of the various phases of the machinery installment, from the purchase to the beginning of the treatment, the charge of work supported in the three considered years, the daily use of the machinery and the problems deriving from days of time out of services due to failures or to periodical maintenance have then been studied. The analysis of the average values of the parameters studied and of the range of their variability allows us to find out the sector in which it is possible, also at present, to intervene in order to ameliorate the employment of a linear accelerator, regarding the costs and the performance.

Cost-Benefit Analysis↗