Outputting a radio in email template for forms

I have made a form with a radio field. The form has about 10 fields. All works fine: The submitted information is saved correctly in Perch admin. The response email(s) are outputting the correct information when using the 'email template: plain text only'.

Then I made an email template. All fields had the correct output except for 1 field: a radio field. I have tried making a debug for it, but didn't succeed.

Form template snippet

<div class="gender"> 
  <perch:label class="mainlabel" for="gender">Male/Female</perch:label>
  <perch:input type="radio" name="gender" options="Male,Female" />
</div>

Email template snippet, the 'gender' field is at the end of the line.

<tr>
  <th>Name</th>
  <td><perch:email id="firstname" /> <perch:email id="lastname" /> <perch:email id="gender" /></td>
</tr>  

I hope this is sufficient information for you to analyse.

So the problem is, the gender field will not output to the email (template). Can you help?

thx