Sentinel node mapping of VX2 carcinoma in rabbit thigh with CT lymphography using ethiodized oil.
OBJECTIVE
To assess the feasibility of computed tomography (CT) lymphography using ethiodized oil for sentinel node mapping in experimentally induced VX2 carcinoma in the rabbit thigh.


METHODS
This experiment received approval from the institutional animal use and care administrative advisory committee. Twenty-three rabbits with VX2 carcinoma in the thigh underwent CT before and after (1 hour, 2 hour) peritumoral injection of 2 mL ethiodized oil. After the CT examination, sentinel nodes were identified by peritumoral injection of methylene blue and subsequently removed. The retrieved sentinel and non-sentinel lymph nodes were investigated with radiographic and pathologic examinations. Based on the comparison of CT findings with those of radiographic and pathologic examinations, the diagnostic performance of CT for sentinel node identification was assessed.


RESULTS
All 23 rabbits showed 53 ethiodized oil retention nodes on post-injection CT and specimen radiography, and 52 methylene blue-stained nodes at the right femoroiliac area. Of the 52 blue-stained sentinel nodes, 50 nodes demonstrated ethiodized oil retention. Thus, the sentinel node detection rate of CT was 96% (50 of 52). On pathologic examination, 28 sentinel nodes in 17 rabbits (nodes/rabbit, mean ± standard deviation, 1.7 ± 0.6) harbored metastasis. Twenty seven of the 28 metastatic sentinel nodes were found to have ethiodized oil retention.


CONCLUSIONS
Computed tomography lymphography using ethiodized oil may be feasible for sentinel node mapping in experimentally induced VX2 carcinoma in the rabbit thigh.
Department of Radiology, Seoul National University Bundang Hospital, Seongnam 463-707, Korea.
Yoon Jin
YJ
Lee
Department of Radiology, Seoul National University Bundang Hospital, Seongnam 463-707, Korea.
Young Hoon
YH
Kim
Department of Radiology, Seoul National University Bundang Hospital, Seongnam 463-707, Korea.
Kyoung Ho
KH
Lee
Department of Radiology, Seoul National University Bundang Hospital, Seongnam 463-707, Korea.
Ji Hoon
JH
Park
Department of Pathology, Seoul National University Bundang Hospital, Seongnam 463-707, Korea.
Hye Seung
HS
Lee
Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 110-744, Korea.
Seung Chai
SC
Jung
Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 135-720, Korea.
Seung-Moon
SM
Joo
D000818:Animals; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D003287:Contrast Media; D004998:Ethiodized Oil; D005240:Feasibility Studies; D005260:Female; D007267:Injections; D008197:Lymph Node Excision / Q000379:methods; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008220:Lymphography / Q000379:methods*; D011817:Rabbits; D013848:Thigh; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D004998:Ethiodized Oil
Animal model; Computed tomography; Lymphatic metastasis; Lymphography; Sentinel lymph node