The computation of perturbative corrections to processes involving heavy quarks is crucial for
the precision program of the LHC and future colliders. In this article, we describe a powerful
approach to calculate higher-orders in QCD skipping the traditional subtraction method. Our
proposal is based on the loop-tree duality (LTD) theorem, which allows to rewrite virtual contributions
in terms of integrals over the real emission phase-space. Then, we proceed to combine
both real and virtual contributions at the integrand level, obtaining regular expressions that can
be numerically integrated in four space-time dimensions. In this way, we avoid dealing with
complicated massive Feynman integrals and introducing infrared counter-terms. Some reference
examples are explained, in order to exhibit the potential of our method.