[18F-PSMA PET/CT imaging following biochemical recurrence of prostate cancer].

INTRODUCTION

In cases of biochemical recurrence following radical prostatectomy, the European Association of Urology recommends PSMA PET/CT imaging, which has become increasingly available in Hungary in recent years.

OBJECTIVE

Our aim was to evaluate the clinical applicability of 18F-JK-PSMA-7, a fluorine-18-labeled radiopharmaceutical suitable for routine use, in the detection of recurrent prostate cancer in patients presenting with biochemical recurrence.

METHOD: We retrospectively analyzed 67 patients who underwent 18F-JK-PSMA-7 PET/CT due to rising PSA levels (>0.2 ng/ml) following definitive treatment (radical prostatectomy ± adjuvant treatment). Images were assessed for local recurrence, lymph node, and distant metastases. Patients were stratified into subgroups based on pre-scan PSA level (>1 ng/ml vs. ≤1 ng/ml) and PSA doubling time (PSAdt, <6 months vs. ≥6 months). Detection rate was calculated, and in positive cases, correlations were analyzed between the maximum standardized uptake value (SUVmax) of the most intense lesion and PSA or PSAdt values.

RESULTS

PSMA-avid lesions consistent with prostate cancer were detected in 51 patients (76.1%). Detection rate was significantly higher in the PSA >1 ng/ml group (88.1% vs. 56%; p = 0,019). Among positive cases, SUVmax values were also significantly elevated in patients with higher PSA and shorter PSAdt.

DISCUSSION: Our results confirm the clinical relevance of PSMA PET/CT in detecting biochemical recurrence. PSA level significantly influenced both detection rate and lesion avidity, supporting the need for a predictive PSA threshold in patient stratification. In contrast, PSAdt had less impact on detectability, though some correlation with SUVmax was noted. The 18F-labeled compound's technical advantages further support its clinical utility.

CONCLUSION

18F-JK-PSMA-7 PET/CT is a sensitive imaging modality for identifying recurrent prostate cancer. Stratifying patients by PSA levels may enhance diagnostic yield and clinical decision-making. Orv Hetil. 2025; 166(51): 2018-2023.