The accumulation of radiolabeled SST analogue in retroorbital tissue has been demonstrated in vivo with 111In-DTPA-D-Phe1-octreotide (Octreoscan) scintigraphy [35–38] and the level of uptake of somatostatin analogs in orbital scintigrams was positively correlated with TAO activity, supporting the possibility that SSTR expression may decrease during treatment. This evidence concerns the gene SST and thromboangiitis obliterans.