Impact of 18F-DOPA PET/CT imaging on the management of patients with brain tumors: The referring physician’s perspective

Objectives Imaging studies that do not affect patient management are not useful. The amino acid analogue 18F-DOPA is used for detecting primary and recurrent high and low grade brain tumors. We investigated the impact of 18F-DOPA PET/CT on the clinical management of patients with brain tumors.

Methods A prospective survey of referring physicians (n=4) to determine the impact of FDOPA PET/CT imaging on managing patients with brain tumors was condcuted. 62 brain tumor patients who underwent 18F-DOPA PET/CT brain scans were enrolled (July 09 - Dec 10). A pre-PET questionnaire inquired about indication, tumor histology/grade, level of suspicion for tumor recurrence, and planned management. A post PET questionnaire categorized PET findings (negative, equivocal, positive), and the level of suspicion for tumor recurrence and changes in treatment.

Results Frequent indications for 18F-DOPA PET/CT scans were (1) new or changed T2-signal on MRI (32%), (2) new or changed contrast enhancement on MRI (26%) or (3) follow-up on prior 18F-DOPA scan (15%). The 18F-DOPA PET/CT findings were negative for tumor in 20 (32%), equivocal in 6 (10%) and positive in 36 (58%) patients. The clinical suspicion for recurrence increased in 32%, remained unchanged in 52% and decreased in 16% of patients. Management changes after 18F-DOPA PET/CT imaging occurred in 40% of patients. Most frequent changes were from wait & watch to chemotherapy (n=7), chemotherapy to wait & watch (n=4), wait & watch to chemotherapy and radiation (n=2), chemotherapy to surgery (n=2), and chemotherapy plus radiation to chemotherapy (n=2).

Conclusions 18F-FDOPA PET imaging has a substantial impact on managing patients with brain tumors. The most frequent management change was from wait & watch to chemotherapy