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Jean-Jacques Mazeron

Publications and source records attributed to Jean-Jacques Mazeron.

31 records · Page 2Linked to original sources
PubMed2003

Radiation-induced cognitive dysfunction: the protective effect of ethyol in young rats.

PURPOSE: To evaluate the protective learning and memory effect of Ethyol in irradiated young rats. METHODS AND MATERIALS: One hundred twenty-eight 45-day-old Wistar rats received whole brain fractionated radiation (30 Gy), whereas 48 rats received sham irradiation. Four irradiated subgroups were defined: saline, 37.5 mg/kg, 75 mg/kg, and 150 mg/kg Ethyol. Sequential behavioral studies including one-way and two-way avoidance tasks were undertaken before and after radiation. RESULTS: Before radiation, the performances of all groups were similar. For the one-way avoidance task, at 1, 3, and 6 months postradiation, saline-irradiated rats had a lower percentage of avoidance than sham- or Ethyol- (75 or 150 mg/kg) irradiated rats (p <or= 0.001). Nevertheless, lower percentage of avoidance (p <or= 0.001) was only seen at 1 month postradiation in saline-irradiated rats, after comparison with their preradiation values. For the two-way avoidance task, performed only after radiation, saline-irradiated rats had a lower percentage of avoidance than sham- or Ethyol- (150 or 75 mg/kg) irradiated rats at 1, 2.5, 4.5, and 7.5 months (p = 0.000). Rats treated with Ethyol did not differ from sham-irradiated rats in both avoidance tasks, except for the 37.5 mg/kg-Ethyol group which showed lower performances 6 months postradiation (p = 0.005, one-way avoidance). CONCLUSIONS: Treatment with 75 or 150 mg/kg of Ethyol prevents radiation-induced learning and transitory memory dysfunction in young rats.

Amifostine↗
PubMed2003

Proton beam therapy in the management of central nervous system tumors in childhood: the preliminary experience of the Centre de Protonthérapie d'Orsay.

BACKGROUND: The purpose of the study was to evaluate clinical results and complications of a combination of proton and photon irradiation administered to 17 children with selected central nervous system (CNS) tumors. PROCEDURE: Between July 1994 and September 2000, 17 children, aged from 5 to 17 years (median: 12 years) with intracranial benign (6 cases) or malignant (11 cases) tumors, were treated with photons (median dose: 40 Gy; 24-54) and protons (median dose: 20 CGE; 9-31) at the Centre de Protonthérapie d'Orsay (CPO). RESULTS: Mean follow-up was 27 months (3-81). Two patients recurred locally (one marginal and one in situ). Fifteen patients are alive and doing well. Overall, 12, 24, and 36-month local control rate was 92 +/- 8% and, 12, 24, and 36-month overall survival rates were 93 +/- 6%, 83 +/- 11%, and 83 +/- 11%, respectively. Clinical initial symptoms remained stable or subsided in all patients. Early toxicities were in the expected range. CONCLUSIONS: With a mean 27 months follow-up, protontherapy was well tolerated for doses upto 69 CGE and with an excellent local control rate.

Adolescent↗
PubMed2003

Radiation therapy for chordoma and chondrosarcoma of the skull base and the cervical spine. Prognostic factors and patterns of failure.

BACKGROUND: Prospective analysis of local tumor control, survival and treatment complications in 67 consecutive patients treated with fractionated photon and proton radiation for chordoma or chondrosarcoma of the base of the skull and the cervical spine. PATIENTS AND METHODS: Between December 1995 and January 2000, 67 patients with a median age of 52 years (range: 14-85 years), were treated at the Centre de Protonthérapie d'Orsay (CPO), France, using the 201-MeV proton beam, 49 for chordoma and 18 for chondrosarcoma. Irradiation combined high-energy photons and protons. Photons represented two thirds of the total dose and protons one third. The median total dose delivered within gross tumor volume (GTV) was 67 Cobalt Gray Equivalents (CGE; range: 60-70 CGE). RESULTS: Within a median follow-up of 29 months (range: 4-71 months), the 3-year local control rates were 71% and 85% for chordomas and chondrosarcomas, respectively, and the 3-year overall survival rates 88% and 75%, respectively. 14 tumors (21.5%) failed locally (eight within the GTV, four within the clinical target volume [CTV], and two without further assessment). Seven patients died from their tumor and another one from a nonrelated condition (pulmonary embolism). The maximum tumor diameter and, similarly, the GTV were larger in relapsing patients, compared with the rest of the population: 56 mm vs 44 mm (p = 0.024) and 50 ml vs 22 ml (p = 0.0083), respectively. In univariate analysis, age < or = 52 years at the time of radiotherapy (p = 0.002), maximum diameter < 45 mm (p = 0.02), and GTV < 28 ml (p = 0.02) impacted positively on local control. On multivariate analysis, only age was an independent prognostic factor of local control. CONCLUSION: In chordomas and chondrosarcomas of the skull base and cervical spine, combined photon and proton radiation therapy offers excellent chances of cure. In two thirds of the cases, relapses are located in the GTV. Maximum diameter, GTV, and age are prognostic indicators of local control. These results should be confirmed during a longer follow-up.

Adolescent↗
PubMed2003

Three irradiation treatment options including radiosurgery for brain metastases from primary lung cancer.

PURPOSE: To determine local control and survival rates in 92 patients with 145 brain metastases treated with three options of radiotherapy including stereotactic radiosurgery (SR). METHODS: Between July 1994 and August 2002, 92 consecutive patients with 145 metastases were treated with a SR, 34 with initially SR alone, 22 initially with an association of whole-brain radiotherapy (WBRT) and 36 with SR alone for recurrent new brain metastasis after WBRT. At time of treatment, extracranial disease was controlled in 46 (50%) and uncontrolled in 46 (50%). Pathologies were adenocarcinoma in 54 cases (59%), squamous cell carcinoma in 14 cases (15%), small cell carcinoma in 10 cases (11%) and miscellaneous in 14 cases (15%). All patients underwent only one treatment fraction for 1 or 2 metastases in 73 cases (83%) and for more than 2 metastases for the others. RESULTS: The characteristics of patients and metastases in the group treated initially with SR alone and in the group treated initially with WBRT+SR were comparable. Median follow-up was 29 months (18-36). Overall, the median and the 1- and 2-year rates of overall survival were, respectively, 9 months, 37 and 20%. A controlled extracranial disease, a high Karnofsky index and a low number of metastasis were independent prognostic factor of overall survival, respectively, HR 0.53 (95% CI 0.31-0.90, P=0.01), HR 0.95 (95% CI 0.92-0.97, P=0.0002), and HR 0.48 (95% CI 0.25-0.90, P=0.02). Thirteen metastases were not controlled (9%). Six-month and 1-year local control rate were, respectively, 93 and 86%. High delivered dose was an independent prognostic factor of local control, HR 0.41 (95% CI 0.18-0.95, P=0.03). A controlled extracranial disease was favourable independent prognostic factor of brain free-disease free survival, HR 0.47 (95% CI 0.2-0.98, P=0.04). Although there was a trend of a better local control, overall and brain disease free survivals rates in the WBRT+SR group compared to SR alone one, the difference were not statistically different. CONCLUSION: Local control and survival rates are acceptable for a palliative treatment for the three option of treatment. In this series, the number of patients is not enough great to conclude to the necessity of the association of WBRT to SR. Re-irradiation is a safe treatment after new metastases appeared in previously irradiated area.

Adult↗
PubMed2003

Predictive factors of radiation necrosis after radiosurgery for cerebral metastases.

The aim of this study was to determine if the risk of radiation necrosis after radiosurgery is related to the presence of normal tissue included in the prescription volume. Between 1994 and 2001, 377 patients representing 760 lesions were treated by radiosurgery in our center with a 10-MV LINAC. The median age of the patients was 57 years (range 30-86 years), median tumor volume was 4.9 cm(3), median peripheral dose (70%) was 15.6 Gy and median dose at the isocenter was 21.6 Gy. Karnofsky index, disease control and number of lesions were the only parameters significantly influencing survival (median 8.6 months), while disease-free survival was correlated with the number of isocenters. Seven percent of the patients presented severe complications, including nine episodes of radiation necrosis. The only parameter influencing the risk of radiation necrosis was the conformity index (p = 0.001). These findings emphasize the importance of reducing falsely irradiated normal tissue during radiosurgery to prevent radiation necrosis.

Adult↗
PubMed2003

[Chemoradiotherapy of solid tumours in the adult: current views and perspectives].

Clinical trials carried out during the last decade have given clear indication on the potential of concomitant association of radiotherapy and chemotherapy for improving local control and survival rates in the management of locally advanced solid tumours. In most trials, cisplatin was used alone or in combination with other drugs. Meta-analysis pointed to the potential of these combinations in head and neck, lung, cervical and oesophagus cancers. The interaction of radiotherapy with chemotherapy for these solid tumours appears to depend primarily on the time-scheduling of radiation versus drug exposure and on radiation fractionation. Major improvements aiming at increasing therapeutic index, are expected from studies on the mode of action of drugs and on the mechanisms of acute toxicity of drugs and radiation.

Adult↗
PubMed2003

[Stereotaxic irradiation of brain metastasis in elderly patients].

AIMS: Analysis of results of stereotactic irradiation for brain metastases for patients older than 70 years. PATIENTS AND METHODS: From January 1994 to January 2002, 53 patients received stereotactic irradiation for a total of 105 brain metastases. There were 26 females and 27 males. Median age was 73 years (70-86). Median interval between cancer diagnosis and brain metastases was 18 months (0-216). Metastases were diagnosed after development of related clinical symptoms in 34 patients (64.1%). Patients were irradiated for one to 6 metastases. Twenty-nine patients (54.7%) were treated for only one metastasis. Median metastasis diameter and volume were respectively 24 mm (5-74.9 mm) and 2.1 cc (0.02-71.3). Eighty-three metastases were supratentorial (79%), and 22 subtentorial (21%). Forty-five underwent only one procedure (85%) and 8 patients underwent a second procedure for one or several new metastases. Three patients were irradiated with whole brain radiotherapy (WBRT) concomitantly of radiosurgery and three patients received WBRT after radiosurgery for development of more than four metastases or for carcinomatous meningitis. RESULTS: The median follow-up was 8 months (1-33). Median minimum and maximum doses delivered to the metastases were respectively, 16.42 Gy (6.5-20.5) and 20.36 Gy (13.2-41.9). The median overall survival duration was 9 months. Three-, 6-, 12- and 18-month overall survival rates were respectively, 85.6% +/- 5, 65.2% +/- 7.1, 35.5% +/- 7.8 and 26.6% +/- 8. According to unifactorial analysis, two prognostic factors of overall survival were retrieved, extra-cranial disease status and RPAa (Recursive Partitioning Analysis for aged patients) separated in three classes including Karnofsky index performance status and extra-cranial disease status, respectively p = 0.043 et p = 0.016. According to multifactorial analysis only RPAa was an independent prognostic factor of overall survival (p = 0.019, RR: 0.89, 95% confidence interval [0.017-0.47]). Median brain disease-free survival was 12 months. Three-, 6-, 12- and 18-month free-brain disease survival rates were, 81.5% +/- 6.4, 68.7% +/- 8, 47.2% +/- 9.9 and 35.4% +/- 12.6, respectively. No prognostic factor of free-brain disease survival was retrieved. Crude local control rate was 97%. Only three metastases relapsed. Six and 12-month local control rates were 98.6% +/- 1.4 and 88.5% +/- 7.6. Among 34 patients with initial clinical symptoms, one patient presented an aggravation, 9 improved up to complete response (26.5%), 13 patients presented a partial remission (38.2%) and 5 were stabilized (14.7%). For 6 patients, data were not available. We observed 3 radionecroses and 1 hemorrhage of the metastases. CONCLUSION: Radiosurgery in the elderly was efficient and well tolerated. Age alone should not be used to deny potentially beneficial radiosurgery to any patient with brain metastases.

Aged↗
PubMed2002

Highly conformal therapy using proton component in the management of meningiomas. Preliminary experience of the Centre de Protonthérapie d'Orsay.

AIMS: To evaluate the efficacy and the tolerance of an escalated dose of external conformal fractionated radiation therapy combining photons and protons in the treatment of intracranial meningiomas. PATIENTS AND METHODS: Between December 1995 and December 1999, 17 patients received a treatment by 201-MeV proton beam at the Centre de Protonthérapie d'Orsay (CPO) for a meningioma. Five patients presented a histologically atypical or malignant meningioma, twelve patients a benign one that was recurrent or rapidly progressive. In two cases radiotherapy was administered in the initial course of the disease and in 15 cases at the time of relapse. A highly conformal approach was used combining high-energy photons and protons for approximately 2/3 and 1/3 of the total dose. The median total dose delivered within gross tumor volume was 61 Cobalt Gray Equivalent CGE (25-69). RESULTS: Median follow-up was 37 months (17-60). The 4-year local control and overall survival rates were 87.5 +/- 12% and 88.9 +/- 11%, respectively. One patient failed locally within the clinical tumor volume. One patient died of intercurrent disease. A complete or partial clinical improvement was seen in most of patients. Radiologically, there were eleven stable diseases and five partial responses. In 12/15 recurrent cases, the free interval after radiotherapy is longer than that achieved by the initial surgery. This radiotherapy was well tolerated. CONCLUSIONS: In both benign and more aggressive meningiomas, the combination of conformal photons and protons with a dose escalated by 10-15% offers clinical improvements in most patients as well as radiological long-term stabilization.

Adolescent↗
PubMed2002

Head and neck brachytherapy.

Experience accumulated over several decades in the treatment of head and neck tumors by irradiation has demonstrated the need for a high tumor dose to achieve local control. With external beam irradiation alone, it is difficult to spare adjacent normal tissues, resulting in undesirable late effects on the salivary glands, mandible, and muscles of mastication. Interstitial implantation is ideally suited to deliver a high dose limited to the volume of the primary tumor, thus maximizing tumor control while minimizing complications. A large experience has been accumulated with low dose rate (LDR) brachytherapy in treatment of carcinoma of oral cavity, oropharynx, and nasopharynx. Recent analysis of large clinical series provided data indicating that modalities of LDR brachytherapy should be optimized in treating these tumors 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 these 2 last modalities will be discussed.

Brachytherapy↗
PubMed2002

Linac radiosurgery for brain metastasis of melanoma.

PURPOSE: To evaluate the efficacy and toxicity of stereotactic radiotherapy in the treatment of brain metastases of melanoma. PATIENTS AND METHODS: From 1994 to 2001, 25 patients presenting with 61 metastases of cutaneous melanoma were treated with radiosurgery. Median age was 47 years (range: 25-73 years) and median Karnofski performance status 80 (range: 50-100). Twenty patients had one radiosurgery, 5 had two or three. Median metastasis diameter was 21 mm (range: 6-54.4 mm), and median metastasis volume was 1.7 cm(3) (range: 0.4-25.6 cm(3)). Irradiation was delivered by a linear accelerator. Median minimal dose was 14.1 Gy (range: 10-19.4 Gy), and median maximal dose was 20.5 Gy (range: 16-48 Gy). RESULTS: Mean follow-up was 12.6 months (range: 1-85 months). Five metastases progressed (9.8%), 2-12 months after radiosurgery. Three-, 6- and 12-month local control rates were 95 +/- 3, 90 +/- 5 and 84 +/- 7%, respectively. By univariate analysis, only absence of extracranial tumor was a prognostic factor of local control. Three-, 6- and 12-month brain-disease-free survival rates were 75 +/- 9, 68 +/- 11 and 38 +/- 13%, respectively. According to univariate analysis, only the Score Index for Radiosurgery in brain metastases (SIR) was a prognostic factor of brain-event-free survival (p = 0.03). Median survival was 8 months. Three-, 6- and 12-month overall survival rates were 75 +/- 9, 53 +/- 10, and 29 +/- 10%, respectively. According to univariate analysis, extracranial controlled disease status (p = 0.03), and SIR (p = 0.04) were prognostic factors for overall survival. According to multivariate analysis, none was an independent prognosticator for overall survival. Complications were minimal. CONCLUSION: Radiosurgical treatment of brain metastases of melanoma is effective and accurate. The use of radiosurgery alone is an appropriate management strategy for many patients with brain metastases of melanoma.

Adult↗
PubMedDate not supplied

LINAC radiosurgery for brain metastasis of renal cell carcinoma.

The purpose of the study was to evaluate the efficacy and toxicity of stereotactic radiotherapy in the treatment of the brain metastasis of renal cell carcinoma. From 1994 to 2001, 28 patients presenting with 65 metastases of renal cell cancer were treated by radiosurgery. Median age was 55 years (35-75), and median Karnofski performance status ranges between 50 and 100. Seven patients had received whole brain radiotherapy (WBRT) before radiosurgery. Twelve patients were treated by radiosurgery for 1 metastasis, 5 patients for two metastases and 6 for three, and 5 for more than three metastases. One procedure was performed in 22 patients and, 2 or 3 procedures for 6 patients. Median metastasis diameter was 19 mm (5-55 mm). Median metastasis volume was 1.28 cc (0.02-28 cc). Irradiation was delivered by linear accelerator. Median minimal dose (on the 70% isodose) was 14.7 Gy (10.8 Gy, 19.5 Gy), median maximal dose (at the isocenter) 20.5 Gy (14.3 Gy, 39.6 Gy). Median follow-up was 14 months (1-33). Two metastases progressed (3%), 2 and 12 months after radiosurgery. Overall, crude local control rate was 97% and 3-, 6- and 12-month local control rates were 98% +/- 2%, 98% +/- 2%, and 93% +/- 5%, respectively. In univariate analysis, no prognostic factor of local control was retrieved. Median brain disease-free survival was 25 months after RS. the 3-, 6- and 12-month distant brain control rates were 91% +/- 4%, 91% +/- 4%, and 70% +/- 12%, respectively. Median survival duration was 11 months. The 3-, 6-, 12- and 24-month overall survival rates were 82% +/- 7%, 67% +/- 9%, 48% +/- 10%, and 33% +/- 10%, respectively. According to univariate analysis, only site of metastasis was overall survival prognostic factor. Radiosurgery for brain metastasis of renal cell carcinoma is an effective and accurate treatment. The use of radiosurgery alone is an appropriate management strategy for many patients with brain metastasis of renal cell carcinoma. Radiosurgery is efficient even after development of new metastasis appearing after WBRT.

Adult↗
PubMedDate not supplied

[Radiation therapy for chordomas and chondrosarcomas of the base of the skull and cervical spine].

PURPOSE: Prospective analysis of local tumour control, survival and treatment complications in 67 consecutive patients treated with fractionated photon and proton radiation for a chordoma or a chondrosarcoma of the base of the skull and of the cervical spine. PATIENTS AND METHODS: Between December 1995 and January 2000, 67 patients with a median age of 52.3 years (14-85), were treated using 201 MeV proton beam of the centre de protonthérapie d'Orsay (CPO), 49 for a chordoma and 18 for a chondrosarcoma. Irradiation combined high-energy photons and protons. Photons represented 2/3 of the total dose and protons 1/3. The median total dose delivered within gross tumour volume was 67 Cobalt Gray Equivalent (CGE) (60-70). RESULTS: With a mean follow-up of 32 months (4-71), the 3-year local control rates were for chordomas and chondrosarcomas of 70.8% and 85.2%, respectively and 4-year overall survival rates of 87.7% and 75%, respectively. Fourteen tumours (21.5%) failed locally (eight within the gross tumor volume, four into the CTV and 2 in an unknown site). Seven patients died of tumour and one of intercurrent disease. In univariate analysis, age inférieur ou égal à 52.3 years (p = 0.002), maximum tumoral diameter < 44.7 mm (p = 0.02) and GTV < 28.4 mL (0.02), at time of radiotherapy, influenced positively the local control. According to multivariate analysis, only age was an independent prognostic factor of local control. Only five (7.7%) patients presented grade 3 or 4 complications. CONCLUSION: In base of skull chordomas and chondrosarcomas, the combined photon and proton therapy offers excellent chances of cure at the price of an acceptable toxicity. These results should be confirmed with a longer follow-up.

Adolescent↗