  The spinor-helicity formalism has proven to be very efficient in the
calculation of scattering amplitudes in quantum field theory, while the loop
tree duality (LTD) representation of multi-loop integrals exhibits appealing
and interesting advantages with respect to other approaches. In view of the
most recent developments in LTD, we exploit the synergies with the
spinor-helicity formalism to analyse illustrative one- and two-loop scattering
processes. We focus our discussion on the local UV renormalisation of IR and UV
finite amplitudes and present a fully automated numerical implementation that
provides efficient expressions which are integrable directly in four space-time
dimensions.
