AIM - The objective of this study was to analyze the safety and efficacy of (177)Lu-labeled DOTAGA-based prostate specific membrane antigen (PSMA) ligand (177)Lu-DOTAGA-(I-y)fk(Sub-KuE) ((177)Lu-PSMA) in patients with metastatic castration-resistant prostate cancer (mCRPC).
METHODS - Fifty-six mCRPC patients underwent PSMA radioligand therapy (RLT) with (177)Lu-PSMA. (68)Ga-PSMA-HBED-CC ((68)Ga-PSMA) PET/CT was used for patient selection and follow-up after PSMA-RLT. Hematological status, renal function and serum prostate specific antigen (PSA) levels were documented before and after therapy. Dosimetry was performed in 30 patients.
RESULTS - (177)Lu-PSMA demonstrated high absorbed tumor doses (median, 3. 3 mGy/MBq) as compared to normal organs. Parotid glands received higher doses (1. 3 mGy/MBq) than kidneys (0. 8 mGy/MBq). All patients tolerated the therapy without any acute adverse effects. Except mild reversible xerostomia in two patients, no long-term side effect was observed. There was a small, but statistically significant reduction in erythrocyte and leukocyte counts, of which only the erythrocytes decreased slightly below the normal range. No thrombocytopenia occurred. The severity of pain significantly reduced in 2/6 (33. 33%) patients. Decrease in PSA was noted in 45/56 (80. 3%) patients. In 25 patients, followed up at least 6 months after ≥2 PSMA-RLT cycles, molecular response evaluation ((68)Ga-PSMA PET/CT) revealed partial remission (PR) in 14, stable disease (SD) in 2 and progressive disease (PD) in 9 patients. Contrast-enhanced CT exhibited PR in 5, SD in 13, and PD in 7 patients. The median progression-free survival was 13. 7 months, and the median overall survival was not reached at follow-up of 28 months.
CONCLUSIONS - PSMA-RLT with (177)Lu-PSMA is feasible, safe and effective in end-stage progressive mCRPC with appropriate selection and follow-up of patients by (68)Ga-PSMA PET/CT applying the concept of Theranostics.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2016 Jan 21 [Epub ahead of print]
Richard P Baum, Harshad R Kulkarni, Christiane Schuchardt, Aviral Singh, Martina Wirtz, Stefan Wiessalla, Margret Schottelius, Dirk Mueller, Ingo Klette, Hans-Jürgen Wester
Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Germany;, Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Germany;, Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Germany;, Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Germany;, Pharmaceutical Radiochemistry, Germany;, Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Germany;, Klinikum rechts der Isar, TU Muenchen, Germany;, Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Germany;, Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Germany;, Technische Universitaet Muenchen, Germany.