Gazetteer	Radiation Oncology Structures Ontology	Source
http://purl.obolibrary.org/obo/GAZ_00423640	urn:absolute:RadiationOncologyStructuresOntology#Colon	LOOM
http://purl.obolibrary.org/obo/GAZ_00002897	urn:absolute:RadiationOncologyStructuresOntology#Colon	LOOM