Biomedical subjects

Renaud De Crevoisier

Publications and source records attributed to Renaud De Crevoisier.

5 recordsLinked to original sources

PubMed2005

Ultrasound-based localization.

Ultrasound is a noninvasive, relatively easy, rapid, and real-time imaging technique for organ targeting for radiotherapy. Its application has been developed to a greater extent in prostate cancer than in other sites in which it has been shown to improve the accuracy of daily treatment delivery. With the move toward dose escalation and the need to maximally spare the adjacent critical structures through more conformal therapy and smaller field margins, an innovative technique for accurate and reproducible tumor targeting is mandatory. Basic ultrasound principles and organ location lend themselves well to the application of this modality in prostate cancer. Promising results using daily ultrasound-guided B-mode acquisition and targeting for patients with upper abdominal tumors suggest an area for additional trials and study. For breast cancer radiotherapy, ultrasound serves to define involved primary and nodal sites, especially in patients in whom surgical evaluation will not be the first therapeutic step.

Abdominal Neoplasms↗

PubMed2004

Combined treatment of anaplastic thyroid carcinoma with surgery, chemotherapy, and hyperfractionated accelerated external radiotherapy.

PURPOSE: To analyze a prospective protocol combining surgery, chemotherapy (CT), and hyperfractionated accelerated radiotherapy (RT) in anaplastic thyroid carcinoma. METHODS AND MATERIALS: Thirty anaplastic thyroid carcinoma patients (mean age, 59 years) were treated during 1990-2000. Tumor extended beyond the capsule gland in 26 patients, with tracheal extension in 8. Lymph node metastases were present in 18 patients and lung metastases in 6. Surgery was performed before RT-CT in 20 patients and afterwards in 4. Two cycles of doxorubicin (60 mg/m(2)) and cisplatin (120 mg/m(2)) were delivered before RT and four cycles after RT. RT consisted of two daily fractions of 1.25 Gy, 5 days per week to a total dose of 40 Gy to the cervical lymph node areas and the superior mediastinum. RESULTS: Acute toxicity (World Health Organization criteria) was Grade 3 or 4 pharyngoesophagitis in 10 patients; Grade 4 neutropenia in 21, with infection in 13; and Grade 3 or 4 anemia and thrombopenia in 8 and 4, respectively. At the end of the treatment, a complete local response was observed in 19 patients. With a median follow-up of 45 months (range, 12-78 months), 7 patients were alive in complete remission, of whom 6 had initially received a complete tumor resection. Overall survival rate at 3 years was 27% (95% confidence interval 10-44%) and median survival 10 months. In multivariate analysis, tracheal extension and macroscopic complete tumor resection were significant factors in overall survival. Death was related to local progression in 5% of patients, to distant metastases in 68%, and to both in 27%. CONCLUSIONS: Main toxicity was hematologic. High long-term survival was obtained when RT-CT was given after complete surgery. This protocol avoided local tumor progression, and death was mainly caused by distant metastases.

Adult↗

PubMed2003

Cyclooxygenase-2 inhibitor NS398 enhances antitumor effect of irradiation on hormone refractory human prostate carcinoma cells.

PURPOSE: We examined the potential therapeutic effect of NS398, a selective cyclooxygenase-2 (COX-2) inhibitor, combined with irradiation on human prostate adenocarcinoma DU145 cells. MATERIALS AND METHODS: The effect on tumor growth, proliferation testing and clonogenic survival was determined to evaluate its antitumor effect when exposed to NS398 or combined with irradiation. Immunoblotting analyses were done to detect the expression of COX-2, nuclear factor-kappaB p50 and Rel A p65 because evidence suggested a biological association of COX-2 with alterations in these markers. Reverse transcriptase-polymerase chain reaction was also performed to show its effect on the transcription level of COX-2. RESULTS: Exposure of DU145 cells to NS398 alone suppressed proliferation in a dose and time dependent manner. Examination of the NS398 effect on the radiation response showed marked enhancement of radiosensitivity. Western blot indicated that NS398 down-regulated the expression of COX-2, nuclear factor-kappaB, p50 and Rel A p65, whereas the effect was more pronounced when combined with irradiation. Reverse transcriptase-polymerase chain reaction showed that the NS398 antitumor effect was associated with COX-2 transcription inhibition. Importantly COX-2 expression was enhanced by irradiation but this phenomenon was abolished when cells were exposed to NS398. Inhibition of tumor growth in animal model was observed when mice were treated with NS398 alone and irradiation alone, and this effect was maximal when treated with NS398 and irradiation. CONCLUSIONS: These results suggest that NS398 could be used as a potential therapeutic agent combined with irradiation for prostate adenocarcinoma.

Adenocarcinoma↗

PubMed2002

Chromosomal aberrations induced by chemotherapy and radiotherapy in lymphocytes from patients with breast carcinoma.

PURPOSE: Stable chromosomal aberrations (SCAs) have been found in circulating lymphocytes from patients treated for breast carcinoma. Therefore, we tried to define their incidence in such patients, to determine an in vitro dose-effect relationship, and to correlate these data with clinical parameters. METHODS AND MATERIALS: This prospective study included 25 patients who, after surgery, underwent either radiotherapy (RT) alone (n = 15) or RT combined with chemotherapy (n = 10). SCAs were scored using the fluorescent in situ hybridization technique before RT and 4 and 12 months after RT. Dose-effect curves were established by in vitro irradiation of blood samples with 2 and 4 Gy, before and after treatment. RESULTS: In all patients, the rate of SCAs increased significantly after external irradiation. No significant decrease in SCAs was observed during the first year after RT. RT and chemotherapy had no effect on the lymphocyte in vitro dose-effect relationship. No relationship was found in the distribution of patients between the yield of SCAs scored after external irradiation and after in vitro irradiation. SCAs after RT or in vitro irradiation did not correlate with family history of breast carcinoma or acute toxicity of treatment. More significantly, the yield of SCA after external irradiation was strongly related to the irradiation of the internal mammary chain and the supraclavicular lymph node area, suggesting that the volume of irradiated blood vessels was an essential parameter in determining the rate of SCAs. CONCLUSION: A high and stable yield of SCAs persisted at least 1 year after external irradiation. The nature of the volume irradiated containing large blood vessels was the major determinant of the observed biologic dose.

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↗