This is an known issue which has been fixed in the development version. You can download the hotfix from http://www.lead-dbs.org/release/download.php?id=hotfix which is updated several times everyday. Just extract the hotfix and overwrite into your leaddbs installation folder. You can also do it from the leaddbs “Install” menu via “install development version of leaddbs”. Let me know if you still have problem with VTA calculation. Btw, if you see error about intersection when you calculate VTA, you can try to uncheck the “use atlas” optin in teh vta setting window.