Which type of CT scan required for detecting metastatic clear cell renal cancer in chest/abdomen, is it plain or contrast?

This sounds like. Radiology calling. It should be the radiologist deciding, but the contrast tends to identify vessels, and some tumors "flush" with contrast. The contrast is iodine based. One wants to see vessels in venous phase in a kidney tumor, and looking for metastasis to liver and lung. I vote for contrast.
CAT SCAN/METASTATIS. The best way to check for metastatic disease in chest and abdomen is with and without contrast.