RT Journal Article SR Electronic T1 Decision making in radiation oncology based on 68Ga-PSMA-11 PET/CT for primary and recurrent prostate cancer JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1507 OP 1507 VO 59 IS supplement 1 A1 Will, Leon A1 Koerber, Stefan A1 Kratochwil, Clemens A1 Haefner, Matthias A1 Rathke, Hendrik A1 Kopka, Klaus A1 Mier, Walter A1 Debus, Juergen A1 Haberkorn, Uwe A1 Giesel, Frederik YR 2018 UL http://jnm.snmjournals.org/content/59/supplement_1/1507.abstract AB 1507Objectives: 68Ga-PSMA-11 PET/CT is a promising diagnostic tool for staging and restaging of prostate cancer patients and often leads to a change in radiotherapeutic (RT) management. Most data available show the impact of 68Ga-PSMA-11 PET/CT on RT management in the setting of recurrent prostate cancer. Therefore, our study evaluates the impact on RT management in a large cohort of patients with primary and recurrent prostate cancer. Methods: 121 men with prostate cancer who underwent 68Ga-PSMA-11 PET/CT for radiotherapy planning in addition to conventional staging were retrospectively enrolled in this study. 50 patients presented with initial prostate cancer, 11 with prostate-specific antigen (PSA) persistence after surgery and 60 with PSA recurrence after initial therapy. Any changes in TNM staging and/or RT management due to PSMA imaging were analyzed. Results: Overall, TNM staging changed in 40.5% (49/121 patients) (40.5%) and RT management changed in 52.9% (64/121 patients). 68Ga-PSMA-11 PET/CT had a higher impact in patients with recurrent disease (TNM change: 55.0% (33/60 patients); RT concept change: 60.0% (36/60 patients)) compared to men with initial prostate cancer (TNM change: 26.0% (13/50 patients); RT concept change: 44.0% (22/50 patients)). In the group of patients with PSA persistence after initial therapy TNM changed in 27.3% (3/11 patients) and RT concept changed in 54.5% (6/11 patients). Conclusion: 68Ga-PSMA-11 PET/CT is able to detect a high proportion of prostate cancer lesions in primary and recurrent disease leading to a change of RT management in up to 60%. This study suggests that the impact of the diagnostic technology might be greater for men with PSA recurrence. However, it also suggests that it has an important impact on the therapy management in patients with initial prostate cancer. Therefore, 68Ga-PSMA-11 PET/CT appears to be well suited for individualized radiation oncology.