PyQT : How to get checkable items from treeview?

I am a newbie to PyQT and I need some help. I have defined a treeview with checkable items using QStandardItemModel and item.setCheckable(True). That's working. Now, I want to get checkable items and to launch a new interface with these checkable items. I tried to use selected indexes but I don't know how to get checked items. I am really confused and I don't like to use QtreeWidget.

Any ideas to do that ? Iterate over a treeview and get checkable items ?

Thank you in advance.