 They both have similar penetration depth in tissue (5 mm for 186Re and 11 mm for 188Re), but 186Re has advantage of longer lifetime (90 hours vs. 17 hours).188Re is also being used experimentally in a novel treatment of pancreatic cancer where it is delivered by means of the bacterium "Listeria monocytogenes".Related by periodic trends, rhenium has a similar chemistry to that of technetium; work done to label rhenium onto target compounds can often be translated to technetium.