That’s essentially what I did, I’ve posted my code below.

piklist('field', array(
    'type' => 'radio'
    ,'field' => 'news_sidebar_conditional'
    ,'label' => __('Does this news item have a sidebar?', 'piklist-demo')
    ,'choices' => array(
      'show' => 'Yes'
      ,'hide' => 'No'
    )
    ,'value' => 'hide'
  ));

piklist('field', array(
    'type' => 'editor'
    ,'field' => 'news_sidebar'
    ,'scope' => 'post_meta'
    ,'template' => 'field'
    ,'options' => array (
      'wpautop' => true
      ,'media_buttons' => true
      ,'tabindex' => ''
      ,'editor_css' => ''
      ,'editor_class' => ''
      ,'teeny' => false
      ,'dfw' => false
      ,'tinymce' => true
      ,'quicktags' => true
      ,'drag_drop_upload' => true
    )
    ,'on_post_status' => array(
      'value' => 'lock'
    )
    ,'conditions' => array(
      array(
        'field' => 'news_sidebar_conditional'
        ,'value' => 'show'
      )
    )
  ));