SPECT-CT: a valuable method to document the regeneration of lymphatics and autotransplanted lymph node fragments

Abstract

The transplantation of lymph node fragments and stimulation of lymph vessel regeneration seems to be a promising model to prevent lymphoedema in patients after mammary tumour excision combined with axillary lymph node dissection and irradiation. This study evaluated the advantages of SPECT-CT in studying the regeneration of lymph vessels and lymphoid tissue after autologous lymph node transplantation. Five minipigs underwent autologous lymph node transplantation in the left groin. The lymph node was excised, cut into six pieces and embedded into two newly created subcutaneous pouches on this side. The superficial lymph node of the right groin was removed as a control. Five months after surgery the lymph flow of both legs was investigated using conventional lymphoscintigraphy and SPECT-CT with 10 MBq(99m)Tc-nanocolloid in combination with Berlin Blue injected subcutaneously into the draining area. The integration of the transplanted lymph node fragments was shown. The SPECT-CT results correlated with the in situ findings observed at dissection. Afferent and efferent lymph flow could be followed up to the lumbar trunks. The use of SPECT-CT allowed exact localisation of the lymph node fragments in three-dimensional space and the regeneration of the lymph node fragments was documented histologically. SPECT-CT is a good method to evaluate lymphatic flow and document lymph node regeneration. The data suggest that autologous lymph node transplantation is a promising model for prevention of lymphoedema.