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R de Crevoisier

Publications and source records attributed to R de Crevoisier.

12 recordsLinked to original sources
PubMed2006

[Prostate localization systems for prostate radiotherapy].

The development of sophisticated conformal radiation therapy techniques for prostate cancer, such as intensity-modulated radiotherapy, implies precise and accurate targeting. Inter- and intrafraction prostate motion can be significant and should be characterized, unless the target volume may occasionally be missed. Indeed, bony landmark-based portal imaging does not provide the positional information for soft-tissue targets (prostate and seminal vesicles) or critical organs (rectum and bladder). In this article, we describe various prostate localization systems used before or during the fraction: rectal balloon, intraprostatic fiducials, ultrasound-based localization, integrated CT/linear accelerator system, megavoltage or kilovoltage cone-beam CT, Calypso 4D localization system tomotherapy, Cyberknife and Exactrac X-Ray 6D. The clinical benefit in using such prostate localization tools is not proven by randomized studies and the feasibility has just been established for some of these techniques. Nevertheless, these systems should improve local control by a more accurate delivery of an increased prescribed dose in a reduced planning target volume.

Humans↗
PubMed2006

[Image-guided radiotherapy by in-room CT-linear accelerator combination].

Target localization has become increasingly important in the advent of IMRT, as treatment margins are reduced and target doses are increased with high-dose gradients outside this target volume. The in-room CT on rails-LINAC system allows CT imaging while the patient remains immobilized in the treatment position just prior to treatment. The anatomic inter- and intra-fractional variations can be therefore quantified during a course of treatment. The position of the tumour can be checked and corrected before the fraction. In case of modification of tumour shape, a re-planning of the treatment is also feasible. However, several issues remain: the integration with routine clinical treatment due to a lack of software tools, the frequency of imaging, and the cost-efficiency ratio. The clinical experience is yet very limited but CT-image-guided radiotherapy appears promising for prostate, brain and spinal tumours.

Brain Neoplasms↗
PubMed2006

A phase II monocentric study of oxaliplatin in combination with gemcitabine (GEMOX) in patients with advanced/metastatic transitional cell carcinoma (TCC) of the urothelial tract.

BACKGROUND: The aim of the study was to evaluate the activity and the safety of the gemcitabine-oxaliplatin (GEMOX) combination as first-line treatment in advanced/metastatic transitional cell carcinoma (TCC) of the urothelial tract. MATERIALS AND METHODS: Patients with metastatic or unresectable TCC, PS < or =2, creatinine < or =1.5 upper limit of normal range (UNL) and measurable disease according to RECIST criteria were treated with a combination of gemcitabine (1500 mg/m(2)) followed by oxaliplatin (85 mg/m(2)) on day 1 and 15 of a 28-day cycle. RESULTS: A total of 123 cycles were administered to 30 patients (median 4, range 1-8). Three complete responses (CR) and 11 partial responses (PR) were observed. Overall response rate (ORR) was 47% (95% CI 28% to 66%). Median overall survival (OS) was 15 months (95% CI 8-31). Grade 3 and 4 neutropenia were reported in three and one patient, respectively; grade 3 anaemia in three patients; grade 3 and 4 thrombocytopenia in two and one patient, respectively; grade 1, 2 and 3 peripheral neuropathy in 14, 11 and two patients, respectively; grade 2 and 3 fatigue in 13 and seven patients respectively. CONCLUSIONS: The GEMOX combination is active in advanced/metastatic TCC with minimal toxicity and needs to be evaluated in a selected population of unfit patients and compared with other non-cisplatin-containing regimens.

Aged↗
PubMed2003

[Brachytherapy in cervix cancers: development of techniques and concepts].

Brachytherapy plays an important role in the treatment of patients with cervical carcinoma. Technical modalities have evolved during the last years and have benefited from imaging modalities development, specially MRI. Imaging modalities contribute to a better knowledge of tumoral extension and critical organs. Ultrasound during brachytherapy has led to the almost complete eradication of uterine perforation. In the future, a more systematic use of systems allowing optimization may induce a better dose distribution in the tumor as well as in the critical organs. Recent data provided information in favor of a better analysis in the relative role of dose-rate, total dose and treated volume and their influence on the local control and complication incidence. Concomitant radiochemotherapy represents a standard in the treatment of patients with tumoral size exceeding 4 cm. Some questions still remain: is concomitant chemotherapy of benefit during brachytherapy? Is there any place for complementary surgery, specially in patients with complete response after external irradiation with concomitant chemotherapy and brachytherapy? In order to answer the former question, a phase III randomized trial is going to start, with the Fédération Nationale des Centres de Lutte Contre le Cancer as a promoter.

Antineoplastic Agents↗
PubMed2002

[Recommendations for quality control in curietherapy].

Brachytherapy consists of sealed radioactive source implantation. The diversity in the nature of radioelements, in their energy and activity requires strict implantation and utilization rules. These rules include radioactive source physical parameters check, after-loading machine and treatment planning system quality assurance and safe and reproducible dosimetric systems. Patient and medical workers information guarantee radioprotection and prevention of accidental exposures.

Brachytherapy↗
PubMed2000

Radiotherapy in head and neck cancer in the elderly: a challenge.

Elderly patients represent the most rapidly growing subgroup of the patient population in France and in the majority of industrialized countries. The effect of age in terms of the prognosis and response to treatment remains unclear. The management strategy (curative versus palliative) for head and neck cancer in the elderly has given vent to divergent opinions and controversies in several respects (the type and quality of treatment, quality of life and economic consequences). This review only focuses on the radiotherapy schedule and head and neck cancers. We compare aged patients with head and neck cancer to younger patients in terms of clinical features, tumor biology, type of treatment, side effects and response. We conclude that if the patient is in a good general condition following a complete evaluation of the cancer, physicians should propose curative treatment with radiotherapy because retrospective trials demonstrate that response in older patients when treated aggressively is comparable to that of younger patients. However, specific trials concerning aged patients with head and neck cancer, quality of life and radiotherapy are warranted.

Age Factors↗
PubMed2000

[Concomitant radiochemotherapy in cancer of the cervix uteri: modifications of the standards].

For a long time, combined external irradiation and brachytherapy has been considered as the standard treatment in patients with advanced cervical cancers. Recently, five clinical randomized trials assessing the role of cis-platin-based chemotherapy delivered concomitantly to radiotherapy have been conducted in the United States. Another clinical randomized trial assessing the role of epirubicin was conducted by the Queen Mary Hospital in Hong Kong. With more than 2,000 enrolled patients, these studies showed converging results with an overall and disease-free survival improvement in the arms combining cis-platin and epirubicin-based chemotherapy and irradiation. These combinations led to a significant decrease in loco-regional evolution or recurrence rates, or even in pulmonary metastases rates. The relative risk of recurrences was decreased by 50%. The relative risk of death was decreased by 40%. The differences, however, were less significant in patients with advanced stages III or IVA. Hematological and digestive acute toxicity was significantly higher in the radiochemotherapy groups, but long-term complications were comparable. The results of these randomized trials have led to a modification in the standard of treatment in these poor prognosis cervix cancers. Five of the randomized trials evidenced the superiority of cis-platin-based chemotherapy, but the optimal chemotherapeutic regimens remain to be defined.

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

[Dose-effect of chemotherapy in bronchial small-cell cancer].

Treatment of patients with small-cell lung cancer (SCLC) remains disappointing despite high initial complete response rate. The dramatic initial chemosensitivity of tumor cells is frustrated by the early emergence of drug resistant clonogenic cells, regardless of front line treatments. Enhancement of dose-intensity (DI) can be achieved by various strategies: initial or late intensive chemotherapy with the use of hematological supports, moderate increase in the initial dose of chemotherapy or intensive weekly chemotherapy. Although the dose relationship is fairly well established regarding the response rate, the effect of DI on survival is not clearly shown in most of the different trials. But the effect of a moderate increase in the initial dose of cisplatinum and cyclophosphamide on survival, opens new directions in the therapeutic strategy of SCLC. The contribution of hematopoietic growth factors and reinfusion of hematopoietic progenitors may be of great interest in the management of this disease.

Antineoplastic Agents↗
PubMedDate not supplied

[Curietherapy in uterine cervix cancers: what therapeutic trends?].

Brachytherapy is a fundamental step in the treatment of patients with cervical cancer. Brachytherapy allows a significant increase in the local control rate as well as the survival rate. Brachytherapy has to be performed as soon as possible after external irradiation in order to maintain the overall treatment time below 53 days. Technical and dosimetric data characterizing low dose-rate brachytherapy using ICRU 38 recommendations have led to an improvement in local control and a decrease in complications. Data are less well known for other dose rates. The role of interstitial brachytherapy is not clearly defined and its potential benefit is probably balanced by an increase in severe complications. Concomitant brachy-chemotherapy requires further clinical investigations, even if concomitant radio-chemotherapy has become a standard in advanced cervical cancers.

Antineoplastic Agents↗