How to adapt #prefix/#suffix for each option in radio form using hook_form_alter()?
In your form_alter you can tell drupal to use your custom theme_radio like this:

$form['attributes']['#theme'] = 'MYCUSTOM_radio_theme';


Then in 'MYCUSTOM_radio_theme:

$element = $variables['element'];


$element['#attributes']['type'] = 'radio';



element_set_attributes($element, array('id', 'name','#return_value' =&gt; 'value'));



if (isset($element['#return_value']) &amp;&amp; $element['#value'] !== FALSE &amp;&amp; $element['#value'] == $element['#return_value']) {
    $element['#attributes']['checked'] = 'checked';



}
  _form_set_class($element, array('form-radio'));

  return '&lt;div class="test"&gt;&lt;input' . drupal_attributes($element['#attributes']) . ' /&gt;&lt;/div&gt;';