Adding findings from positron emission tomography (PET)/computed tomography (CT) imaging, using the radiopharmaceutical 18F-DOPA, to other diagnostic data prompted physicians to change their original management recommendations for almost half of patients with known or suspected brain tumors. These results suggest that imaging amino acid transporters such as 18F-DOPA (3,4-dihydroxy-6-F-18-fluoro-L-phenylalanine) have a potentially important role in the management of persons with brain tumors.
In the study, published in The Journal of Nuclear Medicine (2012;53:393-398), referring physicians were asked to complete a pre-PET/CT survey relating to 58 consecutive patients with known or suspected brain tumors. The survey posed questions about indication, tumor histology or grade, level of suspicion for tumor recurrence, and planned management.
After obtaining PET/CT imaging studies, the physicians completed a second questionnaire as to whether the imaging findings should be categorized as negative, equivocal, or positive. The participants were also asked to report their level of suspicion for primary or recurrent brain tumors and intended management changes prompted by findings on the scan. A third questionnaire, completed 6 months after PET/CT, was designed to determine patient outcome (recurrence and survival).
Of the 58 cases included in the study, clinical suspicion for recurrence increased in 33%, remained unchanged in 50%, and decreased in 17% after the PET/CT result was added to the available diagnostic data. A total of 26 patients experienced recurrence; the remaining 32 had stable disease or remained disease-free.
Intended treatment changes were precipitated by 18F-DOPA PET/CT findings for 41% of the patients. The most frequent changes were from wait-and-watch to chemotherapy (six patients [25%]), and from chemotherapy to wait-and-watch (four patients [17%]). Additional follow-up revealed that 75% of the intended treatment changes were implemented. ONA