In renal cell carcinoma (RCC) patients, lymph node metastases detection and treatment are the most critical issues in daily clinical decision-making. Indeed, conversely to other oncological settings, a) nodal status imaging, b) sentinel node technique and c) standard lymphadenectomy have been demonstrated inadequate in the staging and management of RCC patients. A novel, accurate, standardized imaging technique is urgently needed in RCC setting to detect macro and micro nodal invasion, to identify those patients who are at higher risk of having nodal metastases, to accurately plan the best management. Recent studies suggested combining 18F-FAZA PET with CT scanning in the detection of cancer-induced hypoxia.The investigators propose to test 18F-FAZA PET-CT in detecting nodal metastases to improve the management of RCC patients.

Inclusion Criteria:

• age of at least 18 years with diagnosis of RCC;
• patients candidates to radical nephrectomy and extended lymphadenectomy
• clinical T4 cancers or renal masses with evidence of lymphadenopathies at preoperative CT scan or larger tumor (max diameter>10 cm)
• performance status 0-1;
• expected survival time of at least 3 months;
• recovery from toxic effects of any previous treatment;
• serum biochemical and haematological measurements within healthy parameters.
• Female patients of childbearing age were requested to have a negative pregnancy test
• ability to understand and understand informed consent
• acceptance and signature of informed consent

Exclusion Criteria:

• other medical conditions that might limit the amount of antibody to be administered;
• New York Heart Association Class III/IV cardiac disease;
• pregnancy and breastfeeding
• eGFR<30;
• women of child-bearing age who do not agree to use contraceptives to avoid pregnancy;
• history of autoimmune hepatitis;
• allergy to iodine;
• unavailability or immunological and clinical follow-up assessments;
• participation in another clinical trial involving an investigational agent within 4 weeks of study enrolment

Patients candidates to radical nephrectomy and extended lymphadenectomy for clinical T4 cancers (clinical Nany) or renal masses with evidence of lymphadenopathies at preoperative CT scan (clinical Tany N1) or larger tumor (clinical Tany Nany and max diameter>10 cm).