A system and method for determining the location of wireless sensors are disclosed. The first contact beam and the second contact beam have substantially parallel distal end portions, and at least one of the distal end portions includes an upstanding guide surface configured to receive and align a connection pin between the distal end portions. Preferred estradiol metabolites include 2-methoxyestradiol, 4-methoxyestradiol, 2-hydroxyestradiol, and 4-hydroxyestradiol, andor to synthetic derivatives and analogues thereof or prodrugs thereof.