To evaluate the impact of PSMA PET versus conventional imaging for staging, and the effect of dose escalation (DE) to metastatic lymph nodes in cN1 prostate cancer patients treated with EBRT and ADT.
A retrospective multicenter analysis included 197 propensity score-matched patients (77 staged with PSMA PET, 120 with conventional imaging) treated with EBRT and ADT, with or without DE to lymph node metastases. Matching criteria were T stage, nodal involvement, imaging modality, Gleason score, and ADT duration. Primary endpoint was metastasis-free survival (MFS); secondary endpoints included overall survival (OS), locoregional control (LRC), and toxicity.
Median follow-up was 42 months (IQR: 25-59). Median EQD2 (alpha/beta=1.5) to elective nodes was 46 Gy, and to metastatic nodes, 66 Gy (PSMA PET) and 63 Gy (conventional imaging). The 3-year MFS was 80.5% (95% CI: 71.3-90.8%) for PSMA PET and 77.2% (95% CI: 69.5-85.8%) for conventional imaging; 5-year MFS was 59.3% versus 65.8% (P=0.57). OS at 5 years was 82.2% (PSMA PET) and 77.4% (conventional imaging) (P=0.72). On multivariable analysis, ISUP grade group 3-5 predicted earlier metastasis (HR: 4.03, 95% CI: 1.61-10.06; P=0.003); higher prostate dose (EQD2 ≥113 Gy) improved MFS (HR: 0.53, 95% CI: 0.30-0.95; P=0.033); long-term ADT (≥24 mo) improved OS (HR: 0.38, 95% CI: 0.19-0.78; P=0.009). No significant difference in toxicity was observed between groups.
PSMA PET staging and nodal dose escalation >60 Gy were safe but did not improve MFS, OS, or LRC. ISUP grade group 3-5 and higher prostate dose significantly influenced outcomes.
Clinical nuclear medicine. 2026 Apr 06 [Epub]
Mateusz Bilski, Federico Mastroleo, Artur J Chyrek, Łukasz Kuncman, Piotr Lelek, Magdalena Stankiewicz, Alfonso Gomez-Iturriaga, Marcin Miszczyk, Wojciech Burchardt, Adam Kluska, Aleksandra Napieralska, Andrzej Kukiełka, Katarzyna Konat-Bąska, Rafał Stando, Michał Dec, Ewelina Piliszczuk, Robert Matys, Tomasz Bajon, Maciej Trojanowski, Adam Chicheł, Piotr Wojcieszek, Jacek Fijuth, Thomas Zilli, Amar Kishan, Barbara Alicja Jereczek-Fossa
Department of Radiotherapy, Affidea Nu-med Center of Oncology Diagnostics and Therapy, Zamosc, Poland., Department of Radiation Oncology, Mayo Clinic, Rochester, MN., Department of Brachytherapy, Greater Poland Cancer Centre., Department of Radiotherapy, Medical University of Lodz., Department of Brachytherapy, Maria Skłodowska-Curie National Research Institute of Oncology, Gliwice branch, Gliwice, Poland., Department of Radiation Oncology, Cruces University Hospital, Biobizkaia Health Research Institute, Basque Country University (UPV/EHU), Bilbao, Spain., Department of Urology, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria., Department of Radiotherapy, Maria Sklodowska-Curie National Research Institute of Oncology, Branch Gliwice, Gliwice., Department of Radiotherapy, NU-MED Cancer Diagnostics and Therapy Centre, Zamość., Department of Radiotherapy, Lower Silesian Oncology, Pulmonology and Hematology Center., Department of Radiotherapy, Holy Cross Cancer Center, Kielce., Department of Radiotherapy, Gdynia Oncology Center, Gdynia., Department of Radiotherapy, International Oncology Center, Koszalin., II Department of Radiotherapy., Greater Poland Cancer Registry, Greater Poland Cancer Centre, Poznań, Poland., Department of Radiation Oncology, Oncology Institute of Southern Switzerland, EOC, Bellinzona, Switzerland., Department of Radiation Oncology.