Assessment of 99mTc-NTP 15-5 Uptake on Cartilage, a New Proteoglycan Tracer

Inclusion Criteria: Inclusion criteria specific to group 1: \- Patient with painful unilateral osteoarthritis of the knee as femorotibial pattern defined by a radiographic score of 0/1 from Kellgren / Lawrence and an average WOMAC score\> or equal to 4 and by minor disorders at MRI (MOCART 2.0 score\> 70). Inclusion criteria specific to group 2: * Patient with non-metastatic breast cancer, hormone receptor positive, HER2 negative, with indication for adjuvant therapy with aromatase inhibitor; treatment not yet started. * Age \<60 years Common inclusion criteria: * Patient with at least 31 healthy joints (based on clinical assessment) * signed written informed consent. * Affiliation to a health insurance scheme. * For women of childbearing age : negative serum pregnancy test at inclusion (less than 7 days prior injection of 99mTc-NTP 15-5). * Willing and able to comply with study visits, treatment, exams and the protocol. Exclusion Criteria: * Patients \<18 years of age. * Pregnant or lactating patient. * BMI\> 30 * History of known allergy to excipients contained in the solution of 99mTc-NTP 15-5 * Chronic inflammatory rheumatism (rheumatoid arthritis, spondyloarthropathy, psoriatic arthritis, etc.) diffuse arthritis (at least 3 joints affected), autoimmune connectivitis, fibromyalgia. * Known chronic joint pathology: osteoarthritis affecting at least 3 joints, autoimmune disease, inflammatory rheumatism (except unilateral knee arthritis). * Persons deprived of their liberty, under guardianship / curatorship, or safeguard of justice. * Treatment with NSAIDs or cessation of less than 48 h. * Inability to comply with medical requirement / follow-up of the trial for geographic, family, social or psychological reasons. These conditions should be discussed with the patient before registration in the study.