  We study the symbology of planar Feynman integrals in dimensional
regularization by considering geometric configurations in momentum twistor
space corresponding to their leading singularities (LS). Cutting propagators in
momentum twistor space amounts to intersecting lines associated with loop and
external dual momenta, including the special line associated with the point at
infinity, which breaks dual conformal symmetry. We show that cross-ratios of
intersection points on these lines, especially those on the infinity line,
naturally produce symbol letters for Feynman integrals in $D=4-2\epsilon$,
which include and generalize their LS. At one loop, we obtain all symbol
letters using intersection points from quadruple cuts for integrals up to
pentagon kinematics with two massive corners, which agree perfectly with
canonical differential equation (CDE) results. We then obtain all two-loop
letters, for up to four-mass box and one-mass pentagon kinematics, by
considering more intersections arising from two-loop cuts. Finally we comment
on how cluster algebras appear from this construction, and importantly how we
may extend the method to non-planar integrals.
