Indirect computed tomography lymphography using iodinated nanoparticles to detect cancerous lymph nodes in a cutaneous melanoma model.
OBJECTIVE
To evaluate differences in contrast uptake in normal and cancerous lymph nodes on indirect computed tomography (CT) in swine, we conducted lymphographic examinations after subcutaneous injection of a lymphotropic iodinated nanoparticle suspension.


METHODS
Perilesional subcutaneous contrast injections (2 ml per lesion) of a 15% wt/vol iodinated nanoparticle suspension were made in immature Sinclair miniature swine (n = 5) with cutaneous melanomas. Average attenuation, iodine concentration, node volume, and total iodine uptake were estimated on the CT scans for each opacified lymph node 24 hr after injection. Nodes were classified as normal or cancerous microscopically, and the percentage of tumor replacement was estimated in cancerous nodes.


RESULTS
Average attenuation and iodine concentration were higher in normal nodes, and total iodine uptake was higher in cancerous nodes with greater than 25% replacement (p < .05). Architectural alterations in opacified cancerous nodes included medullary filling defects, expansile cortical lesions, and disruption of corticomedullary junctions.


CONCLUSIONS
Quantitative and qualitative differences in iodinated nanoparticle enhancement characteristics are useful in distinguishing between normal and cancerous lymph nodes on indirect CT lymphography examinations.
Wisner
E R
ER
Department of Radiology, University of California Davis Medical Center, Sacramento, USA.
Katzberg
R W
RW
Link
D P
DP
Griffey
S M
SM
Drake
C M
CM
Vessey
A R
AR
Johnson
D
D
Haley
P J
PJ
D000818:Animals; D003287:Contrast Media; D003973:Diatrizoate; D007455:Iodine; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008220:Lymphography; D008546:Melanoma, Experimental / Q000000981:diagnostic imaging* / Q000556:secondary*; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000473:pathology*; D013552:Swine; D013556:Swine, Miniature; D014057:Tomography, X-Ray Computed / Q000379:methods
D003287:Contrast Media; C101475:WIN 67722; D003973:Diatrizoate; D007455:Iodine