Evolution of Bone Mineral Density (BMD) in Patients With Lymphoma Undergoing Chemotherapy

Inclusion Criteria: * Subjects aged 18 to 80 with lymphoma, * Histological diagnosis of Hodgkin's lymphoma (HL) or non-Hodgkin lymphoma (NHL) of follicular or aggressive (large cell or other), * Patients who have not yet started their chemotherapy or who have started for less than a month * Patient has signed informed consent. Exclusion Criteria: * Pathological fractures at the time of initial diagnosis of lymphoma, * Compression of neurological epidural, * Patients receiving treatment for osteoporosis (including bisphosphonates, selective modulators of estrogen receptor, calcitonin and parathyroid hormone Teriparatide). * Discovery of osteoporosis or osteopenia fracture during the initial evaluation requiring the establishment of an osteoporosis treatment, * Radiotherapy to the lumbar spine or hip studied, * Location of bone lymphoma in the lumbar spine or hip studied, * History of disorders affecting bone metabolism (prostate cancer with androgen, stomach cancer, hyperparathyroidism, hyperthyroidism, uncontrolled ...) * A person incapable of giving consent personally, * Pregnant or breastfeeding women, * Protected Person (under guardianship) * Patient not affiliated with a social security system.