Prospective monocentric study, non-randomized of the detection of sarcopenia in clinical practice in patients with ovarian or endometrial cancer requiring systemic oncological treatment. main question : Identify the criteria correlated with the presence of sarcopenia (defined by the measurement of the IMS by the CT-X method in L3) among the impedancemetry and the HAS malnutrition criteria. Data collection will be done at 6 months, 12 months after the date of inclusion.