How can I get the value of the selected ChoiceType in Twig?

With Symfony 3.3, I already try something like this, but no response:

<tr>
    {% for choice in form.vars.value.clients %}
        <td>{{ choice.value }}</td>
    {% endfor %}
</tr>

Here is my formType:

$builder->add('name')
        ->add('contact')
        ->add('idprofession')
        ->add('idcard');

I have changed nothing because for the foreign key it is by default a choice, I want to recover the value of id profession