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L Bousquet

Publications and source records attributed to L Bousquet.

5 recordsLinked to original sources
PubMed1993

Effect of drug transit time between exchange locus with plasma and sampling site.

In pharmacokinetic models used to describe the behavior of drugs in living organisms, generally neither the amount of drug flowing in pipes between compartments nor the transfer delay between the plasma-lymph exchange areas and a site of measurement are taken into account. Several former publications dealt with exchanges between two or more different organs assuming that the blood flow was constant or that the variation of the lymphatic flow was negligible or noting that the amount of drug present in pipes was not easily taken into account. In this article, we deal with concentration in a site of interstitial exchanges with regard to concentration in a sampling site with a varying blood flow, assuming that the transit time depends both on the fluid flow and the path length through pipes. In all considered cases, the plasma concentration profile may be highly altered by a change in the flow rate.

Humans↗
PubMed1975

[Influence of inaccuracy of certain parameters on dose distribution in telecobalt therapy (author's transl)].

Progress in dosimetry and in radiobiology together with the evolution of radiation generators led to adopt very elaborated radiotherapy protocols. However, the therapist should have confidence in these protocols on condition that irradiation parameters are strictly respected. For obvious reasons, this is impossible despite the meticulous rules. In this, paper, we therefore intend to study the role of the angle of incidence on the actual distribution of doses; we also study the inaccuracy of certain parameters recorded during preparation for the therapy or shown during successive irradiation courses. In this paper we retain only errors which can be easily quantified. These are errors concerning the irradiation apparatus (source to skin distance, angle of the rays, field dimension) and those due to factors related to the patient treated: contour measurement, entrance point of rays and positional changes of the patient. The different errors can be associated in various ways for a given therapy protocol. For the same reason, an isodose of a given nominal value will have several curves. All these tracings are lined by two curves which we call "superior and inferior envelops": these border the "incertitude area". It can be said that at the end of the treatment, the given isodose lies in this area; it is however impossible to define its form or exact position. A few examples in the text illustrate these results and show the possible practical angles of incidence. If we assume that errors during successive irradiations are distributed at random, a certain compensation is noted and the "areas of incertitude" decrease. But if the errors are constantly on the same side, as is sometimes the case, the dose distribution can be very different from that predicted in the dosimetric protocol.

Breast Neoplasms↗