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J J Mazeron

Publications and source records attributed to J J Mazeron.

At least 19 recordsLinked to original sources
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↗
PubMed1997

[Late effects of ionizing radiations on head and neck region tissues].

Numerous structures are included in the irradiated volume of patients presenting with head and neck cancer: skin, mucosa, bone, teeth, cartilage, muscles, salivary glands, etc. Curative intent treatment of such tumours requires aggressive approach which can lead to severe sequellae. These sequellae are in most cases dose-dependent and volume-dependent. However, an appropriate technique might decrease the severity of such sequellae. Details of these late changes are presented, including their pathophysiology, clinical syndromes, potential treatment, and prevention.

Dose-Response Relationship, Radiation↗
PubMed1997

[Late effects of ionizing radiations on the vulva, vagina and uterus].

Reporting and scoring complications after radiotherapy of gynaecological cancers is difficult because of the variety of treatment techniques involved. Use of an international classification is necessary to compare results obtained in series of patients treated in different institutions. An international group of experts designed in the early nineties the so-called French-Italian glossary. This classification of late effects is now completed with the new LENT SOMA scales. This paper contains details of these late changes, including their pathophysiology, clinical syndromes, potential treatment, and prevention.

Brachytherapy↗
PubMed1997

[Induction chemotherapy followed by concomitant combined radiotherapy and chemotherapy in stage III non-small cell bronchial carcinoma].

PURPOSE: To determine the efficacy and safety of induction chemotherapy followed by concomitant chemoradiotherapy in the treatment of stage III non-small cell lung cancer and whether the response to induction chemotherapy can predict the response to subsequent chemoradiotherapy and survival. MATERIALS AND METHODS: Between December 1987 and June 1993, 46 patients with previously untreated stage III non-small cell lung cancer received every 21 days induction chemotherapy (ICT) including three cycles of 5-fluorouracil (600 mg/m2/d in short infusion from d1 to d5), cisplatin (15 mg/m2/d from d1 to d5), etoposide (50 mg/m2/d from d1 to d5) and hydroxyurea (1,500 mg/d from d1 to d5). The first 21 patients also received bleomycin (3 mg/m2/d from d1 to d5). All patients received concomitant chemotherapy and had chest radiotherapy (CCRT). Patients received irradiation (65 Gy/33-6 fractions/7 weeks) on d25 after the third cycle of chemotherapy. Concomitant chemotherapy was composed of cisplatin (20 mg/m2) and 5-fluorouracil (500 mg/m2) that were administered each Monday and Thursday during radiotherapy. Maintenance chemotherapy consisted of thiotepa (10 mg/m2) and methotrexate (10 mg/m2) that were administered every 2 weeks for 6 months. RESULTS: Pulmonary toxicity was observed in four out of 21 patients who had received bleomycin and subsequently developed pulmonary fibrosis, leading to death for two of them. ICT alone produced five complete responses (11%) and 13 partial responses (28%). The combination of chemotherapy and radiotherapy led to 19 complete responses (41%) and 14 partial responses (30%). Eighteen of the 18 responders (100%) to ICT responded to subsequent CCRT, of whom 13 (72%) became complete responders. Fifteen of the 28 non-responders to ICT (53%) responded to CCRT, six of them being complete responders (21%) (P < 0.001). The median overall survival rate was 17 months when considering all patients, 25 months in patients responding to ICT and 13 months in non-responders. The 2-year survival rates were 28, 55 and 11%, respectively (P < 0.05). ICT did not influence the rate of subsequent metastatic events. However, locoregional reprogression was lower in responders to ICT. The number of metastatic events was not significantly related to response to ICT. By contrast, the rate of local failure was higher when there was resistance to ICT (75% versus 39%). Out of the 19 complete responders to CCRT (13 responders to ICT and six non-responders to ICT), four developed secondary locoregional reprogression (21%) and six developed metastatic disease (31%). In complete responders to CCRT, the rate of locoregional failure was 15% in responders to ICT (2/13) and 33% (2/6) in non-responders to ICT. Four out of the 13 responders to CCRT after response to ICT (31%) and two out of the six complete responders to CCRT developed metastatic disease after non-response to ICT. CONCLUSION: There is a statistically significant relationship not only between the response to ICT and the response to CCRT, but also between the response to ICT and the local outcome and survival.

Adenocarcinoma↗
PubMed1997

[Postoperative radiotherapy in non-small cell lung cancer. Apropos of a series of 374 cases].

PURPOSE: Several randomized trials have led us to address the usefulness of post-surgical external beam therapy (EBT) in non-oat cell bronchial carcinoma. Results that were obtained in a group of 374 patients submitted between 1977 and 1994 to identical therapy-the follow-up being done by the same team-and results of six randomized trials are analyzed. PATIENTS AND METHODS: The tumor stages were the following: T1, 13%; T2, 56%; T3, 29%; and T4, 2%; N0, 31%; N1, 34%; and N2, 35%. There were 85% histologically complete resections. EBT was administered according to either the classical irradiation scheme (C) or as an 'equivalent hypofractionated dose' (H) in the case of complete resection. When resection was not complete, 60 to 65 Gy were administered according to a C or an H irradiation scheme. The irradiation scheme was C in 73% of the cases and H in 27%. The EBT technique has been chosen to ensure maximum lung sparing. Following a 45 Gy-irradiation with anteroposterior beams, orthogonal or, when necessary, oblique beams were used. Non homogeneity of the lungs was taken into account in establishing the treatment planning. The treatment file was collectively checked by the medical staff in 75% of the cases. EBT was indicated for N+(N1+N2), T3 and incomplete resections. RESULTS: The overall survival was 42% at 5 years and 27% at 10 years. The 5-year survival was 52% for stage I cancer (T1N0-T2N0), 60% for stage II cancer (T1N1-T2N1), 31% for stage IIIa cancer (T3N0, T1-3N2), 45% for complete resection and 30% when resection was not complete. CONCLUSION: Regarding the benefits of post-surgical radiotherapy, the analysis of the six randomized trials does not allow any conclusion. This might be due to either the insufficient number of cases, a follow-up time not long enough, incorrect radiotherapy, or insufficient available data. Comparison of the results pertaining to the six trials with those of our series shows an advantage for the current series, indicating that survival is likely to be improved if EBT is correctly done with regard to the dose, volume and technique used.

Actuarial Analysis↗
PubMed1997

[Role of radiotherapy in the management of adenocarcinoma of the breast accessible to conservative surgery].

Standard treatment for limited stage adenocarcinoma of the breast includes lumpectomy (or a quadrantectomy), axillary node dissection, regional radiation therapy and, if the prognostic factors are unfavourable, chemotherapy and/or hormone therapy. This is supported by the results of American and European randomised trials. There have been many attempts at improving the modalities of conservative surgery and postoperative radiation therapy in order to maximize local control and minimize late sequellae. It is also likely that induction chemotherapy and external beam radiotherapy applied in selected cases increase the proportion of patients who can be offered conservative surgery.

Adenocarcinoma↗
PubMed1997

[Localized prostatic adenocarcinoma: role of pelvic radiotherapy following radical prostatectomy].

Radical prostatectomy after pelvic lymphadenectomy is an effective treatment for patients with T1-2 pN0 adenocarcinoma of the prostate. However, pathologic analysis of resected tissue reveals that in 20 to 40% of clinical stage B lesions, the tumour has extended locally beyond the prostate. This infra-clinical disease may be the origin of local relapse. Radiation oncologists are often asked to deliver post-operative irradiation. There is sufficient evidence in the literature that postoperative radiation therapy can improve local control rate for patients with pT3 pN0 adenocarcinoma of the prostate; however, the effect of this radiotherapy on survival in this category of patients remains unclear. It is the reason why randomised clinical trials have been implemented for investigating the role of pelvic external irradiation with respect to the effects on local control, acute and late morbidity, overall survival and cancer-related survival, and for better defining the selective indications of radiotherapy, regarding pathological data.

Adenocarcinoma↗
PubMed1997

[Radiotherapy of glioblastoma].

Glioblastoma cells appear to be inherently radioresistant and to present a significant fraction of hypoxic cells. The most significant prognostic factors to compare results achieved in several series of patients are the age, performance status and quality of surgical resection. Several randomized trials have provided evidence supporting the efficacy of radiation therapy in the treatment of glioblastoma. Prescription of a 60-Gy dose delivered according to a conventional dose-fractionation scheme (single daily fractions of 1.7 to 2 Gy five times per week) in a target volume with a 2-3 cm margin of tissue surrounding the perimeter of the contrast enhancing lesion on computerized tomography and magnetic resonance imaging is derived from observations made in several retrospective and prospective studies. Evidence of improvement in survival was observed neither in patients receiving hyperfractioned and accelerated radiotherapy, nor in patients for whom radiation sensitizers such as nitroimidazole compounds or halogenated pyrimidine analogs were associated to radiation therapy. The addition of nitrosourea to radiotherapy increases the 2-year survival rate by about 10%. Combination of full-dose external beam radiotherapy and brachytherapy or radiosurgery boost in selected patients with glioblastoma leads to an increase in the median survival, while external beam radiation alone in patients with similar prognosis does not.

Age Factors↗
PubMed1997

[Radiosurgery].

Radiosurgery refers to the possibility of the destruction of a small area in the brain with a high dose of radiation, after determination of the target with stereotactic coordinates. Arteriovenous malformations of small size not treatable by direct surgery are obliterated by radiosurgery in nearly 80 p. 100 of the cases. Cerebral metastasis are also effectively treated with a good local control, especially in case of small solitary lesion. In acoustic tumor, of small and medium size, radiosurgery appears to be an alternative to surgery. Other benign tumors (meningioma, pituitary adenoma) have also been treated, but long-term studies are still necessary to evaluate the efficacy of this technic.

Brain Neoplasms↗
PubMed1996

[Radiotherapy of brain tumors].

When radiotherapy is employed for central nervous system tumours, several clinical considerations relating to the special normal tissue environment in which they are located deserve recognition. First of all the radiosensitivity of normal brain is nearly equivalent to that of the majority of the primary tumours requiring irradiation. Secondly destroyed normal neural tissue never regenates, but partial recovery is possible following limited injury. Thirdly definition of the target volume is determined mostly by indirect means from a synthesis of neuroradiological findings (C.T. scans, M.R.I.). Finally the rigidity of the intact cranium confers greater clinical significance on mass effects including postradiotherapeutic edema. Most brain tumours respond to external irradiation which may be applied either postoperatively or definitively, e.g. gliomas, lymphomas, medulloblastomas, and metastases. New stereotactic techniques, including radiosurgery, interstitial brachytherapy, and proton beam radiotherapy allow the delivery of larger dose in a limited volume.

Adult↗
PubMed1996

Intra arterial chemotherapy with ACNU and radiotherapy in inoperable malignant gliomas.

For the non-operable malignant glioma patients, prognosis remains poor, with a survival of 8 months for the glioblastomas (G), and 15 months for anaplastic astrocytomas (AA). 27 histologic proven malignant gliomas (17 AA and 10 G) were treated between April 1991 and June 1992. Median age was 48 years. The therapeutic protocol consisted of three courses of intra arterial chemotherapy (IAC) with ACNU, at intervals of six weeks, and a localised 60 Gy radiotherapy between the first and the second IAC course. 72 courses of IAC were delivered (2.4 per patient). Response rate was 51.8%. Median survival (MS) was 13 months, with a survival rate of 28% at 24 months. For the AA, MS was 21 months, with a survival rate of 37% at 24 months. For the G, median survival was 10 months. Responders were 65% for AA, 30% for G. Non responders all died before 24 months had relapsed with a MS of 9 months. 54% of responding patients had a 2 years survival. Toxicity were acceptable with 7% of haematological toxicity and partial loss of visual acuity in 11% of the case. No chronic neurological sequellae were noted. We compare theses results with two previous trials, concerning inoperable patients, treated by association of radiotherapy and systemic chemotherapy. Survival seems to be equivalent with HeCNU and with this treatment, but toxicity decrease with ACNU. Early radiotherapy does not increase complications. This treatment can be used for patients with inoperable malignant gliomas.

Adult↗