CUTANEOUS DRAINAGE LYMPHATIC MAP WITH INTERSTITIAL MULTIDETECTOR-ROW COMPUTED TOMOGRAPHIC LYMPHOGRAPHY USING IOPAMIDOL: PRELIMINARY RESULTS

Abstract

We performed preliminary tests of thefeasibility of multi-detector computedtomographic lymphography (MDCT-LG) withinterstitial injection of iopamidol for mappingcutaneous lymphatic drainage pathways.MDCT-LG images were obtained followingcutaneous injection of a total of 1ml iopamidolbilaterally into hind legs of 10 dogs. Thelocations of the first draining lymph nodeswere marked on the skin under MDCT-LGguidance. Five dogs served for postmortemexamination of lymphatic anatomy, and theremaining 5 underwent MDCT-LG afterligation of the afferent lymphatic vessels ofthe first draining popliteal nodes. Clinically,MDCT-LG was attempted in 6 patients withcutaneous malignant melanoma and comparedwith Tc-99m-human serum albumin lymphoscintigraphy.MDCT-LG clearly visualized thefirst draining lymph nodes and their afferentlymphatic vessels draining from the contrastinjection sites with detailed underlyinganatomy in all dogs. At surgery, all these firstdraining nodes could be found at predictedlocations under MDCT-LG guidance. MDCTLGshowed rerouting of lymphatic vesselsafter ligation of the afferent lymph vessels ofthe popliteal nodes in the second 5 dogs.Clinically, MDCT-LG also allowed accuratemapping and biopsy of the first draining nodesfrom primary tumors at predicted locations,with minimal skin incision. Lymphoscintigraphyfailed to identify these nodes due tooverlapping radioactivity of clustered nodes ortransport of the radiotracer to subsequentdistant nodes in 4 patients. Although a moreextensive study is warranted for furthervalidation, preoperative interstitial MDCT-LGappears to have the potential feasibility foraccurate sentinel lymph node mapping andbiopsy in patients with cutaneous melanoma.