Ve se essa função te ajuda:
<html>
<head>
<script type="text/javascript">
function habilita_radios( check, id_td_radios )
{
var radios = document.getElementById( id_td_radios ).getElementsByTagName('input');
for( var i=0; i<radios.length; i++ )
{
radios.disabled = check.checked ? '' : true;
}
}
</script>
</head>
<body>
<table>
<tr>
<td><input type="checkbox" name="check1" onclick="habilita_radios( this, 'radio1');"></td>
<td>1 - Apostilas</td>
<td id="radio1">
<input type="radio" name="radio1" value="sim" disabled="disabled" />Sim
<input type="radio" name="radio1" value="nao" disabled="disabled" />Não
</td>
</tr>
<tr>
<td><input type="checkbox" name="check1" onclick="habilita_radios( this, 'radio2');"></td>
<td>2 - Tutoriais</td>
<td id="radio2">
<input type="radio" name="radio2" value="sim" disabled="disabled" />Sim
<input type="radio" name="radio2" value="nao" disabled="disabled" />Não
</td>
</tr>
<tr>
<td><input type="checkbox" name="check1" onclick="habilita_radios( this, 'radio3');"></td>
<td>3 - Livros</td>
<td id="radio3">
<input type="radio" name="radio3" value="sim" disabled="disabled" />Sim
<input type="radio" name="radio3" value="nao" disabled="disabled" />Não
</td>
</tr>
</table>
</body>
</html>