▁in ▁the ▁da ▁V inci ▁S urg ical ▁System ). ▁ ▁C lin ical ▁applications ▁ ▁The ▁major ▁limitation ▁in ▁F GS ▁is ▁the ▁avail ability ▁of ▁clin ically ▁approved ▁flu ores cent ▁d yes ▁which ▁have ▁a ▁novel ▁bi ological ▁indic ation . ▁Ind oc yan ine ▁Green ▁( IC G ) ▁has ▁been ▁widely ▁used ▁as ▁a ▁non - specific ▁agent ▁to ▁detect ▁sent in el ▁l ym ph ▁nodes ▁during ▁surg ery . ▁I CG ▁has ▁the ▁main ▁advantage ▁of ▁absor bing ▁and ▁em itting ▁light ▁in ▁the ▁near ▁inf ra red , ▁allowing ▁detection ▁of ▁nodes ▁under ▁several ▁cent im eters ▁of ▁t issue . ▁M eth yl ene ▁Blue ▁can ▁also ▁be ▁used ▁for ▁the ▁same ▁purpose , ▁with ▁an ▁exc itation ▁peak ▁in ▁the ▁red ▁portion ▁of ▁the ▁spectrum . ▁First ▁clin ical ▁applications ▁using ▁tum or - specific ▁agents ▁that ▁detect ▁depos its ▁of ▁o var ian ▁cancer ▁during ▁surg ery ▁have ▁been ▁carried ▁out . ▁ ▁History ▁ ▁The ▁first ▁uses ▁of ▁F GS ▁dates ▁back ▁to ▁the ▁ 1 9 4 0 s ▁when ▁flu ores ce in ▁was ▁first ▁used ▁in ▁humans ▁to ▁enh ance ▁the ▁imag ing ▁of ▁brain ▁tum ors , ▁c yst s , ▁ed ema ▁and ▁blood ▁flow ▁in ▁v ivo . ▁ ▁In ▁modern ▁times ▁the ▁use ▁has ▁fallen ▁off , ▁until ▁a ▁mult ic enter ▁trial ▁in ▁Germany ▁concluded ▁that ▁F GS ▁to ▁help ▁guide ▁gli oma ▁res ection ▁based ▁upon ▁flu ores c ence ▁from ▁P