Table 3.

Updated recommendations for sst2A immunohistochemistry on formalin-fixed, paraffin-embedded tumor tissues

Method	Use UMB-1 antibody
	Define the best experimental conditions (antibody concentration, antigen retrieval method) in individual laboratories
	Use representative large tissue sections of well-fixed tumors
Analysis of tumor cell staining	Assess only membranous staining
	Assess percentage of stained tumor cells
	Assess staining intensity (according to figure 1)
Interpretation of results	-If >10% tumor cells are stained, the tumor is very likely to express high somatostatin receptor levels that would allow successful in vivo somatostatin receptor targeting -If 1–10% of tumor cells are stained, it is inconclusive if enough receptors for in vivo somatostatin receptor targeting are present. A weak staining intensity in these cases is, however, suggestive of too low somatostatin receptor levels. -If there is no tumor cell staining at all, the tumor is likely not to express enough somatostatin receptors for in vivo somatostatin receptor targeting