Retro peritoneal liposarcomas are rare (less than 15% of sarcomas) whose prognosis is locoregional. In the treatment of retroperitoneal liposarcomas main prognostic factor is the quality of the surgical resection. The effect of radiotherapy combined with surgery is uncertain and until now limited perhaps because of limited prescribed doses (of the order of 45Gy to 50Gy) due to high risk of organ toxicity nearby. The helical tomotherapy is an innovative equipment radiotherapy to make conformational radiotherapy modulation intensity and is particularly suitable for irradiations precision (imaging mode associated with daily scanner) in large complex volumes. Increasing doses (increase of the prescribed dose to 54 Gy, thus potentially curative), the helical tomotherapy should allow to improve the efficacy of radiotherapy.
Retro peritoneal liposarcomas are rare (less than 15% of sarcomas) whose prognosis is locoregional. In the treatment of retroperitoneal liposarcomas main prognostic factor is the quality of the surgical resection. The effect of radiotherapy combined with surgery is uncertain and until now limited perhaps because of limited prescribed doses (of the order of 45Gy to 50Gy) due to high risk of organ toxicity nearby. Two elements can overcome these difficulties: * Preoperative radiotherapy made rather than Postoperatively, the tumor in place back the gastrointestinal tract and reducing toxicity, * The contribution of conformal radiotherapy techniques with intensity modulation (IMRT). The helical tomotherapy is an innovative equipment radiotherapy to make conformational radiotherapy modulation intensity and is particularly suitable for irradiations precision (imaging mode associated with daily scanner) in large complex volumes. Increasing doses (increase of the prescribed dose to 54 Gy, thus potentially curative), the helical tomotherapy should allow to improve the efficacy of radiotherapy.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
48
Evaluation of the efficacy of the combination with radio-surgery helical tomotherapy irradiation to a dose of radiation of 54 Gy in patients with retroperitoneal liposarcoma of operable
Centre Paul Strauss
Strasbourg, Alsace, France
Institut Bergonié
Bordeaux, Aquitaine, France
Centre Claudius Regaud
Toulouse, Midi-Pyrénées, France
Centre René Gauducheau
Nantes, Pays de la Loire Region, France
Institut Curie
Paris, Île-de-France Region, France
Cumulative Incidence Rate of Local Recurrence and Competing Risks (All Patients)
Evaluation of the efficacy of the combination with radio-surgery helical tomotherapy irradiation to a dose of radiation of 54 Gy in patients with retroperitoneal liposarcoma of operable. The effectiveness will be evaluated in terms of local recurrence-free survival 3 years. Given the data and the lack of independence between local recurrence and metastasis events, the Kaplan Meier method cannot be applied. An estimation method adapted to the presence of competing risks is necessary. Including other events (metastasis, deaths...) consist in using a competing risk analysis methodology where the specific incidence of each type of event is estimated in the presence of the other types of events. The following results represent the cumulative incidence (as a percentage) of local recurrence on the one hand and the cumulative incidence of competing risks (distant metastasis or death) on the other hand.
Time frame: 3 years from start of the tomotherapy treatment
Cumulative Incidence Rate of Local Recurrence and Competing Risks (Liposarcoma Well Differentiated)
Evaluation of the efficacy of the combination with radio-surgery helical tomotherapy irradiation to a dose of radiation of 54 Gy in patients with retroperitoneal liposarcoma of operable. The effectiveness will be evaluated in terms of local recurrence-free survival 3 years.Given the data and the lack of independence between local recurrence and metastasis events, the Kaplan Meier method cannot be applied. An estimation method adapted to the presence of competing risks is necessary. Including other events (metastasis, deaths...) consist in using a competing risk analysis methodology where the specific incidence of each type of event is estimated in the presence of the other types of events. The following results represent the cumulative incidence (as a percentage) of local recurrence on the one hand and the cumulative incidence of competing risks (distant metastasis or death) on the other hand.
Time frame: 3 years from start of the tomotherapy treatment
Cumulative Incidence Rate of Local Recurrence and Competing Risks (Liposarcoma Dedifferentiated or Pleomorphic)
Evaluation of the efficacy of the combination with radio-surgery helical tomotherapy irradiation to a dose of radiation of 54 Gy in patients with retroperitoneal liposarcoma of operable. The effectiveness will be evaluated in terms of local recurrence-free survival 3 years.Given the data and the lack of independence between local recurrence and metastasis events, the Kaplan Meier method cannot be applied. An estimation method adapted to the presence of competing risks is necessary. Including other events (metastasis, deaths...) consist in using a competing risk analysis methodology where the specific incidence of each type of event is estimated in the presence of the other types of events. The following results represent the cumulative incidence (as a percentage) of local recurrence on the one hand and the cumulative incidence of competing risks (distant metastasis or death) on the other hand.
Time frame: 3 years from start of the tomotherapy treatment
Percentage of Participants With Disease-Free Survival (All Patients)
Evaluation of the efficacy of the combination with radio-surgery helical tomotherapy irradiation to a dose of radiation of 54 Gy in patients with retroperitoneal liposarcoma of operable. The effectiveness will be evaluated in terms of disease free survival rate at 3 years, with the kaplan-meier method. The disease-free survival time is calculated between the date of the start of the tomotherapy treatment and the date of death, distant metastasis or local recurrence (events), whichever occur first, or the date of last news (censorship).
Time frame: 3 years from start of the tomotherapy treatment
Percentage of Participants With Disease-Free Survival (Liposarcoma Well Differentiated)
Evaluation of the efficacy of the combination with radio-surgery helical tomotherapy irradiation to a dose of radiation of 54 Gy in patients with retroperitoneal liposarcoma of operable. The effectiveness will be evaluated in terms of disease free survival rate at 3 years, with the kaplan-meier method. The disease-free survival time is calculated between the date of the start of the tomotherapy treatment and the date of death, distant metastasis or local recurrence (events), whichever occur first, or the date of last news (censorship).
Time frame: 3 years from start of the tomotherapy treatment
Percentage of Participants With Disease-Free Survival (Liposarcoma Dedifferentiated or Pleomorphic)
Evaluation of the efficacy of the combination with radio-surgery helical tomotherapy irradiation to a dose of radiation of 54 Gy in patients with retroperitoneal liposarcoma of operable. The effectiveness will be evaluated in terms of disease free survival rate at 3 years, with the kaplan-meier method. The disease-free survival time is calculated between the date of the start of the tomotherapy treatment and the date of death, distant metastasis or local recurrence (events), whichever occur first, or the date of last news (censorship).
Time frame: 3 years from start of the tomotherapy treatment
Percentage of Participants With Overall Survival (All Patients)
Evaluation of the efficacy of the combination with radio-surgery helical tomotherapy irradiation to a dose of radiation of 54 Gy in patients with retroperitoneal liposarcoma of operable. The effectiveness will be evaluated in terms of overall survival rate at 1, 3 and 5 years, with the kaplan-meier method. The overall survival time is calculated between the date of the start of the tomotherapy treatment and the date of death (event), or the date of last news (censorship).
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Time frame: 1 year, 3 years and 5 years from start of the tomotherapy treatment