CA9 and head and neck squamous cell carcinoma: The biodistribution of [111In]In-DOTA-ZCAIX:2 was directly compared with [111In]In-DTPA-G250-F(ab′)2 and [111In] In-DTPA-G250 in female BALB/C nu/nu mice bearing two HNSCC xenografts with different levels of CAIX expression.