Aim: Radical prostatectomy (RP) or radiation therapy (RT) are curative options for patients with localized prostate carcinoma (PCa). Local salvage therapy is considered when prostate specific antigen (PSA) recurs after RP at 0.2 – 0.5 ng/mL, or rises >2 ng/mL above nadir after RT. However, only half of patients will benefit of local salvage, which has important side effects. Current imaging methods are inadequate for identifying patients with local recurrence only.

Methods: Fifty-three patients (42 post-RP and 11 post-RT) were referred for ⁶⁸Ga-PSMA-HBED-CC PET/CT to find the substrate for elevated PSA: prostate fossa (PF), locoregional lymph nodes (LN), or distal metastases (M). PET/CT was performed 60 min after 104 ± 30 MBq ⁶⁸Ga-PSMA-HBED-CC. Nominal activity was 1.5 MBq/kg for 3 min/bed; time/bed was extended with less administered activity. Most patients had a delayed pelvis scan at 120 min p.i., after furosemide. Scans were systematically read (positive, equivocal, negative) for the PF, LN and M regions. In 33 cases a multidisciplinary team (MDT) issued an advice, based on clinical parameters and PET/CT.

Results: In 25/42 post-RP patients PET/CT was positive, in 5/42 equivocal and in 12/42 negative. PET/CT was negative in 10/25 (40%) of patients with PSA 0.2 – 0.5 ng/mL, in 2/8 (25%) with PSA 0.6 – 2.0 ng/mL and in 0/9 with PSA >2.0 ng/mL.

In all 11 post-RT patients (PSA 1.3 – 37 ng/mL) PET/CT was positive.

In 21/53 patients, positive LN or M lesions, although unconfirmed, suggested that not local salvage, but alternative options should be considered. In 24/33 cases (74%) actual treatment was corresponding with MDT advice.

Conclusion: ⁶⁸Ga-PSMA-HBED-CC PET/CT is promising for sensitive detection of PCa lesions in patients with PSA recurrence, even at low PSA levels. Prospective studies are warranted to confirm the accuracy of ⁶⁸Ga-PSMA-HBED-CC PET/CT and its role in patient management.