Symfony2 dynamic routing - caching issue

I'm trying to create dynamic routes as I have created a CMS where each page created can be associated to a route. I'm using the example from this link - http://php-and-symfony.matthiasnoback.nl/2012/01/symfony2-dynamically-add-routes/ and all works fine, however the routing is cached, therefore one route will work but then the next won't unless I clear the cache. Is it possible to remove just the routing cache at this stage or is there another alternative? I don't want to remove the whole cache directory on each page load as that wouldn't make sense. Here is the example code:

namespace Acme\RoutingBundle\Routing;

use Symfony\Component\Config\Loader\LoaderInterface;
use Symfony\Component\Config\Loader\LoaderResolver;
use Symfony\Component\Routing\Route;
use Symfony\Component\Routing\RouteCollection;

class ExtraLoader implements LoaderInterface
{
private $loaded = false;

public function load($resource, $type = null)
{
    if (true === $this->loaded) {
        throw new \RuntimeException('Do not add this loader twice');
    }

    $routes = new RouteCollection();

    $pattern = '/extra';
    $defaults = array(
        '_controller' => 'AcmeRoutingBundle:Demo:extraRoute',
    );

    $route = new Route($pattern, $defaults);
    $routes->add('extraRoute', $route);

    return $routes;
}

public function supports($resource, $type = null)
{
    return 'extra' === $type;
}

public function getResolver()
{
}

public function setResolver(LoaderResolver $resolver)
{
    // irrelevant to us, since we don't need a resolver
}
}

Then I've made a service for the ExtraLoader:

<!-- in /src/Acme/RoutingBundle/Resources/config/services.xml -->
<?xml version="1.0" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://s