gistfile1.txt

// Use "appendChild" on the CDATA node we created. 

$placemarkDescriptionNode = $dom->createElement('description');

$placemarkDescriptionCDATANode = $dom->createCDATASection(html_entity_decode($row['description']));

$placemarkDescriptionCDATANode = $placemarkDescriptionNode->appendChild($placemarkDescriptionCDATANode);

// So we create a wrapper node, called "description". 
// Then we create a node that will contain your "CDATA" that's stored in a variable (I get it straight from my database).
// Then we append the CDATA Node into the description/wrapper node.