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Biomedical subjects

J Dutreix

Publications and source records attributed to J Dutreix.

At least 55 records · Page 3Linked to original sources
PubMed1979

Total body irradiation in bone marrow transplantation. Hôpital Saint-Louis results.

Total body irradiation was used in 22 patients as part of their conditionning regimen for bone marrow transplantation. Nine patients with acute leukemia received 1 000 cGy TBI in addition with chemotherapy. None of them survived and the main cause of death was interstitial pneumonitis (50%). 4 patients received 1 000 cGy with a lung shielding of 500 cGy. Two patients with acute leukemia died of leukemia and sepsis, two patients had aplastic anemia, one is surviving, the other died of severe GVHD and infectious complications. Nine patients with severe aplastic anemia strongly immunized by previous blood transfusions received 800 cGy TBI with a lung shielding of 400 cGy. No rejection was observed and 7 patients (63%) are currently alive. One patient died of interstitial pneumonitis probably related to CMV infection, one of subacute necrotizing hepatitis, two of severe acute GVHD. It is concluded from this study that TBI remains the best immunosuppressive conditioning regimen even in strongly immunized patients. It may be a contributing factor of the incidence and severity of interstitial pneumonitis. A reduction of the dose ot the lung to 400-500 cGy seems to decrease the severity of this complication.

Anemia, Aplastic↗
PubMed1979

Time factors in total body irradiation.

The role of time dose factors in the irradiation effect of the bone marrow has been investigated in mice by assessing the lethal dose 50% as a function of fraction number and dose rate. It is compared to the time dose effect in intestinal mucosa and lung, considered as critical tissues, for discussing the differential effect between these tissues.

Animals↗
PubMed1978

[The treatment of the tumors by hyperthermia (author's transl)].

This paper is a review of the biological effects of hyperthermia and of their mechanisms. A great interest has been stimulated for the treatment of the tumors by hyperthermia alone or associated to chemo and radiotherapy. The clinical application needs an accurate control of the temperature which raises difficult technical problems.

Animals↗
PubMed1977

[The value of routine in vivo measurements in radiotherapy (author's transl)].

The authors carried out routine measurements in vivo, and emphasise their value in radiotherapy. After reviewing the objectives of in vivo measurements in general, and showing the problems posed by routine measurements, they describe the technique of measurement using thermoluminescent dosimeters and the problems associated with their use in patients treated with the aid of a 5.5 MV linear accelerator. Results based upon 232 routine measurements made it possible to establish a correlation between the dose delivered and the expected dose. Under optimal functional conditions, almost all the deviations seen were less than 5% whilst higher deviations occurred when the apparatus showed signs of instability. They conclude that routine in vivo measurements are extremely useful in ensuring that planned treatment is carried out in a satisfactory manner and also in the early detection of potential faults in equipment.

Humans↗
PubMed1976

[Time factors factors in radiotherapy. Introduction (author's transl)].

The role of time factors, the fractioning and spread of irradiation, continue to occupy an important place in conference, symposia and meeting of radiotherapists and our own Society has followed this tradition by devoting to the subject this session of the Journées de Radiologie 1975. The problem is a constant feature of everyday clinical practise. Whilst the majority of radiotherapists are prudently attached to the traditional method of 5 sessions per week, they are frequently forced to change this rhythm for pathological reasons, the personal convenience of the patient or problems with apparatus. The association of transcutaneous and curietherapeutic irradiation adds new parameters : the rate of the curie-therapy, the relative contribution of the 2 methods of irradiation, their sequence and the interval which separates them. Poor results of radiotherapy in certain situations indicates the possible value of determining whether other methods of the distribution per session and in time might lead to an improvement. Under these numerous circumstances, one is led to compare different forms of irradiation and to assess their possible biological differences. Objective description of the type of irradiation may be limited to the contents of the treatment sheet. However this does not easily express the biological quantity of the irradiation. As soon as the differences between two types of irradiation involves two parameters, they can no longer be effectively compared. The usefulness of a single figure to express the biological value of irradiation is obvious. With this aim, Cohen proposes calculation of levels of cell survival resulting from irradiation and extracts the parameters of this calculation from clinical results published in the literature. By similar analysis, Ellis has deduced the overall role of time factors which is expressed by the simple relation of the N.S.D., which has itself been at the origin of other expressions seeking to be more convenient and universal. Thus various solutions to the problem are available to radiotherapists. However a wide degree of disagreement exists between them, increasing with differences between the forms of irradiation...

Humans↗
PubMed1976

[Time factors in human skin desquamations (author's transl)].

A clinical study of human skin desquamation has provided the variation of the isoeffect curve as a function of the fraction number and overall time. These results have been compared to ELLIS formula (N.S.D.). These results have been compared to relationships related to intestinal mucosa and lung. Differential effects are put in evidence between these tissues as a function of fractionation and overall time. Such differential effects are likely to exist between tumors and normal tissues; however the basic data are still missing for optimizing the time factors of the therapeutic irradiations.

Humans↗
PubMed1975

Clinical radiobiology of low dose-rate radiotherapy.

Investigative irradiations of human skin have shown that the total dose required to obtain a dry desquamation does not increase with the duration of the irradiation as rapidly as it would be expected from the kinetics of repair of the sublethal injuries. This suggests that an additional mechanism, probably accumulation of the cells in a sensitive phase, occurs during a continuous irradiation with dose-rate higher than 150 rads/hour. This effect seems to vanish at smaller dose-rates.

Cell Survival↗