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A Bridier

Publications and source records attributed to A Bridier.

41 records · Page 3Linked to original sources
PubMed1979

Total body irradiation techniques and dosimetry.

Irradiation techniques and dosimetric methods used for total body irradiation (TBI) performed at Institut Gustave Roussy (Villejuif) are presented. TBI are performed in a 5,6 MV X-ray beam produced by a linear accelerator Neptune. The patient, lying laterally on a couch at 4.20 m from the target, is irradiated by a horizontal beam with a mean nominal dose rate at the abdomen mid-plane of about 9 cGy per minute. The procedure used for TBI consists of three parts in order to deliver 8 Gy in the whole body except for lungs which are protected with a lead screen during a part of irradiation and receive a dose of 4 Gy. We have preferred using "in vivo" measurements methods rather than calculations to determine the doses at different points of the patients. Two kinds of detectors are placed on the patient's skin all along the total body irradiation : two sets of five Therados semi conductors probes permit to control the irradiation and lithium fluoride thermoluminescent dosimeters are used like reference detectors. The dosimetric results obtained during the TBI performed at IGR are discussed.

Abdomen↗
PubMed1977

Whole cutaneous irradiation in mycosis fungoides with 55KV x-rays. Technical study.

The authors describe a technique for a whole cutaneous superficial irradiation of mycosis fungoides by means of a fixed 55 KV X-Rays generator and a moving couche. Results of the dosimetric study are compared with thoses obtained with Lithium fluoride. Since 1964, twenty five patients have been treated. The results appear to be equivalent to those obtained with electrons. The technical problems of each methods are discussed.

Humans↗
PubMedDate not supplied

[Validation of biological dosimetry in patients conditioned with total body irradiation: conventional cytogenetics and in situ hybridization(FISH)].

PURPOSE: Validation of biological dosimetry versus physical dosimetry in malignant haemopathy patients conditioned by total body irradiation (TBI) before bone marrow transplantation (BMT). PATIENTS AND METHODS: The scoring of chromosomal aberrations in peripheral lymphocytes irradiated in vivo was used to perform the biological dosimetry. The data were compared to those obtained with healthy volunteers' total blood exposed to in vitro irradiation with linear accelerator doses (0.2, 0.5, 0.75, 1, 2, 3, 4 and 5 Gy) for dose-response curves. In experimental animal models, can in vivo and in vitro responses be considered as being the same? All the published human data are based on retrospective dose evaluation with very large uncertainties on the dose precisely delivered to the subject. TBI before BMT was taken as a model where the dose calculation results from the physical method, with homogeneous beam and dose delivered precisely along the entire organism. In vivo response allows us to validate biological dosimetry in 15 adult patients (female + male), before (D = 0 Gy) and after the first fraction of 1.8 Gy, delivered by a linear accelerator (18 MV, dose-rate of 15.8 cGy/min-1). Two methods, conventional cytogenetics (CCG) and fluorescent in situ hybridization (FISH painting) of chromosome 4 were respectively used to analyze the unstable chromosome aberrations and stable chromosome aberrations. RESULTS: Healthy volunteer lymphocytes, before irradiation, yielded 0.1% dicentrics and 0.3% translocations of chromosome 4, with 2.5% for the whole genome. Patients before irradiation had 2% dicentrics and 11.48% chromosome 4 translocations for the whole genome. In the 15 patients, for a physical dose of 1.8 Gy, the evaluated biological dose was 1.93 Gy (95% CI: 1.85-2.05 Gy) with conventional cytogenetics and 2.06 Gy (95% CI: 1.75-2.15 Gy) with FISH. CONCLUSION: These results, in which the biologically estimated dose is in complete agreement with the dose calculated by physical dosimetry in the homogeneous irradiation model, suggest the validation of biological dosimetry in TBI conditioning.

Adolescent↗
PubMedDate not supplied

[Preliminary dosimetry study of the Orsay synchrocyclotron proton beam with a view to applying it therapeutically].

Using proton beams for treatment of malignant tumors of the eye allows high dose irradiation of the tumor volume with negligible irradiation of the surrounding critical structures. Actually, the clinical results reported from the Boston or Villigen groups which have experience of such a technique, are impressive. In France, it is planned to use soon 200 MeV proton beams from the Orsay synchrocyclotron 20 km from Paris. Therefore, a feasibility study has been conducted during year 1988, consisting of a dosimetric analysis of the characteristics of the Orsay proton beams. It was concluded that only simple modifications were necessary to make the beam clinically available for protontherapy and more specifically for treatment of uveal melanomas.

Animals↗