We provide a concatenated structure for 2-dimension λ-quasi-twisted (λ-Q2DT) codes over Fq, which is a generalization of the concatenated structure for 2-dimension quasi-cyclic (Q2DC) codes. Further, by trace representations of λ-constacyclic codes, λ-quasi-twisted codes, 2-dimension λ-constacyclic codes and λ-Q2DT codes, we obtain a general lower bound of the minimum distance for λ-Q2DT codes of length mℓk, where m,ℓ and k are relatively prime to q.