--- a/OrthancServer/Sources/ServerJobs/ResourceModificationJob.cpp	Wed Jan 10 07:21:50 2024 +0100
+++ b/OrthancServer/Sources/ServerJobs/ResourceModificationJob.cpp	Mon Jan 22 17:14:11 2024 +0100
@@ -210,7 +210,11 @@
     
     std::unique_ptr<DicomInstanceHasher> originalHasher;
     std::unique_ptr<ParsedDicomFile> modified;
-
+    std::set<std::string> instanceLabels;
+    std::set<std::string> seriesLabels;
+    std::set<std::string> studyLabels;
+    std::set<std::string> patientLabels;
+ 
     try
     {
       ServerContext::DicomCacheLocker locker(GetContext(), instance);
@@ -234,6 +238,15 @@
       boost::recursive_mutex::scoped_lock lock(mutex_);  // DicomModification object is not thread safe, we must protect it from here
 
       modification_->Apply(*modified);
+
+      if (modification_->AreLabelsKept())
+      {
+        GetContext().GetIndex().ListLabels(instanceLabels, instance, ResourceType_Instance);
+        // we must also save the parent labels.  This instance might currently be the only one in the hierarchy and therefore it might be in charge of restoring all labels of the hierarchy
+        GetContext().GetIndex().ListLabels(seriesLabels, originalHasher->HashSeries(), ResourceType_Series);
+        GetContext().GetIndex().ListLabels(studyLabels, originalHasher->HashStudy(), ResourceType_Study);
+        GetContext().GetIndex().ListLabels(patientLabels, originalHasher->HashPatient(), ResourceType_Patient);
+      }
     }
 
     const std::string modifiedUid = IDicomTranscoder::GetSopInstanceUid(modified->GetDcmtkObject());
@@ -318,6 +331,19 @@
                              "Error while storing a modified instance " + instance);
     }
 
+    {
+      boost::recursive_mutex::scoped_lock lock(mutex_);  // DicomModification object is not thread safe, we must protect it from here
+
+      if (modification_->AreLabelsKept())
+      {
+        GetContext().GetIndex().AddLabels(instance, ResourceType_Instance, instanceLabels);
+        GetContext().GetIndex().AddLabels(modifiedHasher.HashSeries(), ResourceType_Series, seriesLabels);
+        GetContext().GetIndex().AddLabels(modifiedHasher.HashStudy(), ResourceType_Study, studyLabels);
+        GetContext().GetIndex().AddLabels(modifiedHasher.HashPatient(), ResourceType_Patient, patientLabels);
+      }
+    }
+
+
     /**
      * The assertion below will fail if automated transcoding to a
      * lossy transfer syntax is enabled in the Orthanc core, and if