Sitefinity Cache Manager

Sitefinity utilizes the Enterprise Library Caching Application Block for caching some of its data. In order to obtain an instance of the ICacheManager interface you have to call the GetCacheManager(string instanceName) method of Telerik.Sitefinity.Services.SystemManager class. Follow is how you can access the Manager.
var cacheManager = SystemManager.GetCacheManager(CacheManagerInstance.Global);

You can add or retrieve contents from the cache as following

string _sCacheKey = "TopNavigationString";

Public string TopNavigationString{
  set{

   cacheManager.Add(sCacheKey ,
      value,
       Telerik.Microsoft.Practices.EnterpriseLibrary.Caching.CacheItemPriority.Normal,
         null,
          Telerik.Microsoft.Practices.EnterpriseLibrary.Caching.Expirations.AbsoluteTime(TimeSpan.FromMinutes(this.CacheTimeoutMinutes)));
  }
  get{
      if (cacheManager.Contains(cacheKey))
      {
           return cacheManager.GetData(cacheKey) as string;

      }
  }
}