In this paper, a new reconfiguration policy and a new algorithm for the virtual topology design, named CONGA-VTD (Cost-OptimizatioN Genetic Algorithm for Virtual Topology Design) for Wavelength-Routed Optical Networks are proposed. The objectives of both proposals are to minimize the Packet Loss Ratio (PLR) and the OPerational EXpenditures (OPEX). A simulation study is presented to demonstrate the advantages of the new techniques in both normal operation and in presence of failures. The reconfiguration policy is compared to two static ones to determine the benefits of the reconfiguration process in terms of PLR, OPEX and resources in operation.