Search PubMed⌕ Search

Biomedical subjects

J Dutreix

Publications and source records attributed to J Dutreix.

At least 37 records · Page 2Linked to original sources
PubMed1986

Biologic and anatomic problems of lung shielding in whole-body irradiation.

Lung shielding by lead blocks for reducing the dose to the lungs in whole-body irradiation results in relative protection of the leukemia cell population. The consequence is acceptable if the dose reduction is moderate (from 10 to 8 Gy) and if the shielded volume amounts to a small fraction (5%) of the body weight. The suggestion was made that certain limits should be put on the extent of shielding, so that the shielded lung fraction represents only 60% of the total lung volume.

Humans↗
PubMed1984

Combined interstitial hyperthermia and brachytherapy: Institute Gustave Roussy technique and preliminary results.

In 1981, a protocol was developed at the Institute Gustave-Roussy, utilizing combined interstitial hyperthermia and brachytherapy, to treat recurrent tumors in previously irradiated areas. This protocol consisted of interstitial hyperthermia, 44 degrees C for 45 minutes, followed immediately by iridium 192 curietherapy, delivering 30 Gy in 2 or 3 days to the tumor volume. Fourteen implantations have been performed in 11 patients. Complete eradication of tumor has been achieved thus far in 10 cases. Two patients were not evaluable because of rapid death resulting from diffuse metastases, and two patients demonstrated a partial response (greater than 50% tumor reduction). Treatment has been generally well tolerated despite prior high dose irradiation. There has been only one serious complication-a large area of painful necrosis following retreatment of a recurrent floor of mouth carcinoma. Special "metallic-plastic" tubes were developed to improve tissue tolerance. We were able to document that a high and homogeneous temperature could be delivered throughout the tumor volume. The technical innovations, and the techniques of implantation and temperature documentation are described below.

Adenocarcinoma↗
PubMed1983

Radiosensitivity in Fanconi anaemia: application to the conditioning regimen for bone marrow transplantation.

Fanconi anaemia, an autosomal recessive constitutional aplastic anaemia, seems to be related to a DNA repair mechanism defect. Bone marrow transplantation is sthe only treatment which can cure these patients. Previous attempts at BMT have shown an increased sensitivity to Cyclophosphamide used for the conditioning. Such a sensitivity has also been observed in vitro when Fanconi anaemia cells were incubated with alkylating agents. We have tested the in vivo radiosensitivity and cell repair after skin contact radiotherapy to calculate the irradiation dose which could be tolerated by FA patients. Eight patients have been tested and the results confirmed the suspected increased radiosensitivity in the majority of patients. Following these results, four patients were conditioned with low dose Cyclophosphamide (20 mg/kg) associated with 5 Grays thoraco-abdominal irradiation. All had a take and no major complication of the conditioning regimen. All are alive in good condition from day 51 to day 330 after transplant. Oesophagitis was one major unexpected complication. This study confirms the possibility of curing FA patients with BMT when the conditioning regimen is modified according to the pathophysiology of the disease.

Adolescent↗
PubMed1983

Technical basis for the application of localized hyperthermia.

Techniques of localized hyperthermia have been developed these last years. Very superficial tumors may be heated by infra-red radiation, radiative diathermy at high frequencies (2450 MHz) or even by techniques of contact hyperthermia. Superficial tumors (some cm deep) may be heated by radiative diathermy at lower frequencies (434 MHz or 915 MHz), inductive diathermy or ultrasound. Deeper tumors (about 10 cm deep) are the most problematic. They may be heated by capacitive diathermy at frequencies of 13.5 or 27 MHz under favourable conditions, or perhaps by ultrasound when multiple transducers are used. Hyperthermic extracorporeal perfusion (in limbs) and interstitial hyperthermia are efficient and promising techniques but their indications are limited.

Diathermy↗
PubMed1982

[Perspectives of hyperthermia in the treatment of tumors of the maxillofacial region].

Hyperthermia used alone or in association with radiotherapy and chemotherapy opens new perspectives in the treatment of tumours. Its application in the maxillo-facial area has special features by virtue of the inhomogeneity of the tissues and the sensitivity of some of them. The region is suitable for the use of interstitial and endocavitary techniques which provide localised and uniform heating. Preliminary clinical study was aimed essentially at the improvement of the technique and the evaluation of tolerance. The effects seen on tumours are encouraging and study is being continued with more routine association of hyperthermia and irradiation.

Diathermy↗
PubMed1981

[Interstitial techniques of hyperthermia (author's transl)].

The interstitial techniques of hyperthermia allow one to obtain a precise specific absorption rate (S.A.R.) in a well-defined volume. We have available a low-frequency prototype amplifier, that is capable of heating up to 6 needles. This device was able to heat small volumes in animals, and then was used for patients. Five superficial tumoral nodules have been treated: the first results seem positive. The next step will be the combination of the techniques of interstitial hyperthermia with brachytherapy.

Animals↗
PubMed1981

Biological and technical principles of total body irradiation for bone marrow graft conditioning.

The aims of total body irradiation, namely immunologic suppression of the hematopoietic tissues and eventually eradication of leukemia, require a large dose which may cause detrimental effects on healthy tissues. The main problem is raised by the interstitial pneumonitis and a relative protection of the lung is advisable. A partial reduction of the dose to the lung may cause an important increase of the number of surviving cells in the cell population the irradiation is aiming aiming at. Technical problems are raised to keep this increase to an acceptable value. A relative protection of the critical tissues can be achieved by a convenient time distribution of the dose, since the repair of sublethal injuries taking place between the sessions of a fractionated irradiation or during the course of low dose rate irradiation is larger for intestine, lung..., than for bone marrow and probably leukemic cells. Animal experiments have provided radiobiological data for estimating the therapeutic benefit related to the fraction number or to the dose rate.

Bone Marrow↗
PubMed1981

[Hyperthermia main techniques (author's transl)].

Superficial tumours with a small thickness can be correctly heated by various techniques. Some difficulties arise for a uniform heating across tumours several centimeters thick; they are considerably increased for deep located tumours. The possibilities of various methods of diathermy are discussed with consideration of blood flow and controlled surface cooling. A peculiar attention is devoted to conductive methods using electrodes supplied by 1 MHz current generator, and placed in contact (tubes, plates) or inside (needles) the tumour.

Animals↗