Unfortunately this is an issue with the spider mode when having a number of pie slices with zero or very small values placed next to each other. There are a few approaches that may be applied dynamically, which you may find appropriate for such scenarios.
The first one would be to disable the spider mode when there are a certain number of items with values of 0 ( or smaller than a certain value ). Another possibility would be to choose not to display labels for such values or for all values and instead use the legend to visualize them. Of course, there is always the alternative of using a different type of series, as for similar data sets as in the attached picture the bar chart type would generally be more appropriate.
the Telerik team