Lymphangiography shows perfusion defect in a lymph node at an early stage of metastasis.

This defect area is a tumor. In this area, there are very few lymph sinuses and blood vessels [1].

Thus, the response rate to systemic chemotherapy via blood flow is low.

References

[1] R. Iwamura, M. Sakamoto, S. Mori, T. Kodama, Imaging of the Mouse Lymphatic Sinus during Early Stage Lymph Node Metastasis Using Intranodal Lymphangiography with X-ray Micro-computed Tomography, Molecular Imaging and Biology 21 (2019) 825-834.