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J J Mazeron

Publications and source records attributed to J J Mazeron.

At least 19 recordsLinked to original sources
PubMed2001

Pulsed dose rate brachytherapy in head and neck cancers. Feasibility study of a French cooperative group.

PURPOSE: To prospectively evaluate the feasibility of pulsed dose rate (PDR) brachytherapy to mimic the continuous low dose rate (cLDR) iridium wire technique in head and neck carcinomas. MATERIALS AND METHODS: A series of 30 patients were included from June 1995 to May 1998. The primaries were located in the oral cavity (four T1, seven T2 and two T3), the velotonsillar arch (eight T1 and eight T2) and the posterior wall (one T3). Thirteen were irradiated by exclusive brachytherapy (dose, > or =45 Gy). The PDR delivered 0.5 Gy/pulse, one pulse/h, day and night, to mimic cLDR irradiation. RESULTS: The implantation was feasible for all the patients, usually easy and of good quality. The mean duration/pulse was 13 min, with a mean source activity of 171 mCi. Patient tolerance was poor in nine cases. Sixteen patients could receive the whole PDR treatment with a total ranging from 30 to 120 pulses without any problem. Seven had short breakdowns (< or =6 h). Seven had definitive breakdowns, but could end the irradiation by manual afterloading of iridium 192 wires. The radioprotection was better (or complete), except for one patient. Most of the breakdowns were related to kinking or flattering of the tube. CONCLUSIONS: PDR is feasible in head and neck carcinomas, but necessitates improvement of the quality and control of the plastic tubes.

Brachytherapy↗
PubMed2000

[Radiotherapy of brain astrocytomas and oligodendrogliomas of the adult].

Gliomas are moderately radiosensitive. The main prognostic factors are the anatomicopathological type and grade of glioma, the performance status, age of the patient and the extent of the surgery. According to data from the literature, high-grade gliomas should be given 60 Gy in five weekly fractions of 1.7 to 2 Gy in a volume including tumor or tumor bed, edema and a 2- to 3-cm margin. A dose of 45 Gy would be sufficient for low-grade gliomas, according to the results of a recent randomized EORTC trial. Brachytherapy and radiosurgery techniques may be indicated in selected cases.

Adult↗
PubMed1999

Breast boost--why, how, when...?

BACKGROUND: Breast conservation management including tumorectomy or quadrantectomy and external beam radiotherapy with a dose of 45 to 50 Gy in the treatment of small breast carcinomas is generally accepted. The use of a radiation boost--in particular for specific subgroups--has not been clarified. With regard to the boost technique there is some controversy between groups emphasizing the value of electron boost treatment and groups pointing out the value of interstitial boost treatment. This controversy has become even more complicated as there is an increasing number of institutions reporting the use of HDR interstitial brachytherapy for boost treatment. The most critical issue with regard to interstitial HDR brachytherapy is the assumed serious long-term morbidity after a high single radiation dose as used in HDR-treatments. METHODS AND RESULTS: This article gives a perspective and recommendations on some aspects of this issue (indication, timing, target volume, dose and dose rate). CONCLUSION: More information about the indication for a boost is to be expected from the EORTC trial 22881/10882. Careful selection of treatment procedures for specific subgroups of patients and refinement in surgical procedures and radiotherapy techniques may be useful in improving the clinical and cosmetic results in breast conservation therapy. Prospective trials comparing on the one hand different boost techniques and on the other hand particular morphologic criteria in treatments with boost and without boost are needed to give more detailed recommendations for boost indications and for boost techniques.

Brachytherapy↗
PubMed1999

Treatment of squamous cell anal canal carcinoma with pulsed dose rate brachytherapy. Feasibility study of a French cooperative group.

BACKGROUND AND PURPOSE: To evaluate the feasibility of pulsed dose rate (PDR) brochytherapy in squamous cell anal canal carcinoma (SCACC). MATERIALS AND METHODS: In this study a series of 19 patients with SCACC were included between 1995 and 1997. All patients were treated with curative intent with external beam radiotherapy (EBRT) (44-50 Gy) and one or two cycles of concomitant fluorouracilcisplatinum. After a gap of 2-3 weeks PDR interstitial brachytherapy was performed with a rigid needles technique. The dose was between 10-25 Gy (PARIS system). RESULTS: All patients are alive. No severe grade 3-4 toxicity was encountered. One local relapse one metastatis were seen in two distinct patients. There was no dysfunction of the after loading machine. CONCLUSION: The feasibility of PDR brachytherapy appears good in SCACC. It is an attractive alternative to low dose rate brachytherapy.

Adult↗
PubMed1999

Treatment of malignant gliomas in the elderly.

The benefit of standard treatment of malignant glioma in older patients is debated. In order to assess the effect of a combination of surgery, radiotherapy and chemotherapy on survival of elderly patients with high grade gliomas, 30 consecutive patients older than 70 years with malignant supratentorial gliomas were studied between 9/93 and 9/96. Median age was 73 years (70-79). The mean Karnofsky performance status (KPS) was 66 (30-100). Patients underwent maximum possible surgery, followed by a course of radiotherapy (45 Gy/25 fractions/5 weeks) with 3 or 4 orthogonal beams and a 2 cm margin around the tumor bed. The administration of chemotherapy was left at the discretion of the responsible physician and 12 patients received reduced dose nitrosourea-based chemotherapy. The overall median survival was 36 weeks. The median time to progression was 26 weeks. Three months after surgery, 26 patients were alive, 5 were in complete response, 2 in partial response and 10 were stabilized. Preradiotherapy KPS was the only significant prognostic factor with a median survival of 40 weeks in patients with KPS > or = 70 and 25 weeks when KPS was < 70 (logrank test, p = 0.05). In responding and stable patients (57% of the group) the median KPS was 68 and 66 at 1 and 3 months after the completion of radiotherapy. There was no case of radiotherapy-induced dementia with this regimen. Four out of 12 patients who received chemotherapy, experienced WHO grade 3/4 hematotoxicity. This study suggest that some patients older than 70 years with KPS > or = 70 may benefit from the treatment of malignant gliomas with surgery followed by reduced dose of limited field radiotherapy. Further studies are needed to define the most appropriate dose of radiotherapy and to evaluate further the risk/benefit ratio of a reduced dose chemotherapy in this population.

Aged↗
PubMed1998

The centenary of discovery of radium.

Henri Becquerel presented the discovery of radium by Pierre and Marie Curie at the Paris Academy of Science on 26th December 1898. One century later, radium has been abandoned, mainly for radiation protection difficulties. It is, however, likely that modern techniques of brachytherapy have inherited to those designed for radium sources, and that radium has cured thousands and thousands patients all over the world for about eighty years. The history of discovery and medical use of radium is summarised.

Famous Persons↗
PubMed1998

How to optimize therapeutic ratio in brachytherapy of head and neck squamous cell carcinoma?

Considerable experience has been accumulated with low dose rate (LDR) brachytherapy in the treatment of squamous cell carcinoma of the oral cavity and oropharynx, 4 cm or less in diameter. Recent analysis of large clinical series provided data indicating that modalities of LDR brachytherapy should be optimized in treating these tumours for increasing therapeutic ratio. LDR brachytherapy is now challenged by high dose rate (HDR) brachytherapy and pulsed dose rate (PDR) brachytherapy. Preliminary results obtained with the last two modalities are discussed in comparison with those achieved with LDR brachytherapy.

Brachytherapy↗
PubMed1998

[Update on radiotherapy].

Explore the source record for details and available documents.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

[Radiotherapy-induced cognitive dysfunction in 4-months-old male Wistar rats]].

PURPOSE: Behavioral dysfunction of memory process arising 4 months after whole brain irradiation (30 Gy/10 fractions/12 days) has been demonstrated in 16-27 month old rats, as compared with non irradiated rats. This study was therefore aimed at delivering the same irradiation in young rats and comparing results with those previously obtained in old rats. MATERIAL AND METHODS: Thirty-three 4-month old rats were included into the study. Eighteen received whole brain irradiation (30 Gy/10 fractions/12 days), and 18 were given sham irradiation. Sequential behavior studies were done before irradiation and during the 7 months following irradiation. RESULTS: Significant decrease in memory function was observed in irradiated rats 1 month (p < 0.001), 3 months (p < 0.013), and 6 months (p = 0.007) post-irradiation. This was accompanied by learning deficit 1 month (p = 0.01), 4.5 months (p = 0.03), and 7 months (p = 0.009) post-irradiation. CONCLUSION: Response to radiation therapy observed in young rats differed from that observed in old rats. Young rats showed earlier decrease in memory function than old rats, but this deficit was followed by partial recovery. Learning deficits also arised earlier in young rats than in old rats. In two cases this deficit was permanent.

Age Factors↗