Dynamic TreeIcon in TreeGrid using SVG

I am trying to customize TreeNode.icon dynamically in the TreeGrid for the nodeIcon (without a static image URL but dynamic update an image e.g. using SVG instead). However, the TreeNode.icon API seems to be restricted to be using a SCImgURL type only.

I just wonder if there is an alternate way to achieve that. Thanks.

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SmartClient Version: v9.1p_2015-02-05/Pro Deployment (built 2015-02-05)
Windows 7 Firefox 36.0 and Chrome 40.0.2214.115 m