Indocyanine green (ICG)-based fluorescence navigation system for discrimination of kidney cancer from normal parenchyma: application during partial nephrectomy.
OBJECTIVE
To determine the definite border between normal and tumor kidney tissues during partial nephrectomy (PN) procedures using intraoperative indocyanine green (ICG)-based fluorescence imaging.


METHODS
Sixteen potential candidates for PN with organ-confined, small renal masses treated between July 2008 and June 2011 at Shimane University Hospital were enrolled. An ICG-based fluorescence navigation (FN) system was used to evaluate the border between the tumor and normal kidney parenchyma (step 1), the cavity following tumor excision (step 2), and the negative surgical margin of resected tissues (step 3). The R.E.N.A.L nephrometry score (RNS) was applied to evaluate the correlation between tumor anatomy and ICG-based fluorescence imaging.


RESULTS
In step 1, in vivo probing revealed 14 tumors with a mean RNS of 7 points that showed quite low ICG fluorescence signals in the tumor mass as compared with normal kidney parenchyma. In step 2, in vivo probing around the bed revealed highly fluorescent signals with no remnant tumor residing in 10 cases with a mean RNS of 6 points. In step 3, ex vivo probing revealed cancer tissues involving normal parenchyma that were completely excised with minimum amounts of normal parenchyma in all 16 resected specimens.


CONCLUSIONS
ICG-based FN system was very helpful for confirming negative margin status in even the most complex cases. Further evaluations may open the door for widespread use of this ICG-based FN system as a feasible and attractive alternative during a PN procedure.
Department of Urology, Shimane University School of Medicine, 89-1 Enya-cho, Izumo 693-8501, Japan. mitsui@med.shimane-u.ac.jp
Yozo
Y
Mitsui
Hiroaki
H
Shiina
Naoko
N
Arichi
Takeo
T
Hiraoka
Shogo
S
Inoue
Masahiro
M
Sumura
Satoshi
S
Honda
Hiroaki
H
Yasumoto
Mikio
M
Igawa
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018207:Angiomyolipoma / Q000473:pathology / Q000601:surgery*; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000601:surgery*; D004396:Coloring Agents; D005260:Female; D005453:Fluorescence; D006801:Humans; D007208:Indocyanine Green; D007275:Injections, Intravenous; D007432:Intraoperative Period; D007672:Kidney Cortex; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods*; D055815:Young Adult
D004396:Coloring Agents; D007208:Indocyanine Green