<prompt> Renal carcinoma with solitary lung secondary is best treated byRadiotherapySurgeryChemotherapyImmunotherapy  <response>: Surgery is the best option because 1 cytoreductive surgery will help in increase the action of immunotherapy 2 metstatectomy surgery to remove metstatectomy with curative intent has good prognosis in pulmonary Mets Ref : Campbell and Walsh urology 11th edition . chapter 63. pg no 1502 