CPT Assistant March 2010 states one surgical component and one guidance code should be reported for each lesion. However, according to CMS National Correct Coding Policy Manual (Chapter 9), Medicare (and others), only allow ONE guidance code PER ENCOUNTER, not per lesion, number of biopsies, etc. (MC guideline does not apply to stereotactic or mammo guidance, since those codes state "each lesion.")
Having said all that, in your example, if they are in the same area, only code one guidance code. If there were biopsies on RT and LT, or one at 12 o'clock and one at 6 o'clock, I would code twice. Check your major carrier's policies and submit accordingly.
Just a side note, we (professional side) are seeing denials (MC, Aetna, and others) on the clip placement as of 2013 because it's now deemed "technical component only." We have been told by a national auditing company to continue to bill the 19295 for 2013, without expectation of payment, and that there are new bundled codes in store for 2014.
Hope that helps!