There are two ways to transmit data from one page to another that are commonly used that don't rely on session variables.
AJAX and <form>
HTML
The form has another page as a target (or chains to one) and the values can be retrieved (each checkbox needs a name='') from the target page. I prefer $_REQUEST['the name']. Going back to the previous page (i.e., the one with the form) typically clears all data. If you
submit it again it will use the current data with no memory of the previous data.
AJAX is executed from a local javaScript and you pass the variables when you execute the send procedure. Unlike the form, it doesn't cause your to load a new page but rather can update your current page. Although not exactly what you want to do, it can be adapted and may give you a better way of thinking about your solution
All of this can be studied via
HERE [^]