Such a folate-based radiotracer would be a very helpful tool to non-invasively discriminate FR-positive (often found in ovarian and NSC-lung cancer) from FR-negative tumors in patients with cancer disease as this would allow selecting FR-positive patients amenable to FR-targeted therapies, e.g. folate-targeted antimitotic substances such as EC145 VintafolideTM (Endocyte Inc.) or anti-FR-antibodies such as FarletuzumabTM (Morphotek Inc).