title: Predictors of Response to Radioligand Therapy of Metastatic Castrate-Resistant Prostate Cancer with 177Lu-PSMA-617.
abstract: Radioligand therapy (RLT) with177Lu-PSMA-617 (PSMA is prostate-specific membrane antigen) is a novel targeted therapy for metastatic prostate cancer. In this study, we evaluated the effect of different pretherapeutic parameters on the therapeutic response measured by prostate-specific antigen (PSA) 2 mo after RLT.
  
  
  
  RLT was performed in 40 hormone-refractory patients with distant metastases and progressive disease (mean age, 71.4 y).68Ga-PSMA-11 PET/CT was performed in all patients 1-2 wk before RLT. All patients were treated with a mean of 6 GBq. The SUVmaxof tumor lesions was determined using region-of-interest analysis. Complete blood counts, renal and liver function assessments, previous therapies, pain medication, and SUVs were included in the analysis. PSA was assessed 2 mo after RLT.
  
  
  
  In the univariate analysis, younger age, higher levels of γ-glutamyl transferase, lower pretherapeutic hemoglobin, a higher Gleason score, a higher number of platelets, higher C-reactive protein, regular need for pain medication, and higher lactate dehydrogenase had a negative impact on the therapeutic response; however, the multivariate analysis revealed that the most significant independent factors were the number of platelets and regular need for pain medication. The response was independent of the amount of PSMA uptake as well as previous therapies and other measured factors.
  
  
  
  A PSA decline of more than 50% was observed significantly more in patients without a regular need for analgesics.
authors: Department of Nuclear Medicine, University Hospital Bonn, Bonn, Germany.
authors: Justin
authors: J
authors: Ferdinandus
authors: Department of Nuclear Medicine, University Hospital Bonn, Bonn, Germany.
authors: Elisabeth
authors: E
authors: Eppard
authors: Department of Nuclear Medicine, University Hospital Bonn, Bonn, Germany.
authors: Florian C
authors: FC
authors: Gaertner
authors: Department of Nuclear Medicine, University Hospital Bonn, Bonn, Germany.
authors: Stefan
authors: S
authors: Kürpig
authors: Institute for Medical Biometry, Informatics and Epidemiology, University of Bonn, Bonn, Germany.
authors: Rolf
authors: R
authors: Fimmers
authors: Department of Nuclear Medicine, University Hospital Bonn, Bonn, Germany.
authors: Anna
authors: A
authors: Yordanova
authors: Department of Urology, University Hospital Bonn, Bonn, Germany; and.
authors: Stefan
authors: S
authors: Hauser
authors: Department of Internal Medicine, MED III, University Hospital Bonn, Bonn, Germany.
authors: Georg
authors: G
authors: Feldmann
authors: Department of Nuclear Medicine, University Hospital Bonn, Bonn, Germany.
authors: Markus
authors: M
authors: Essler
authors: Department of Nuclear Medicine, University Hospital Bonn, Bonn, Germany hojjat.ahmadzadehfar@ukb.uni-bonn.de.
authors: Hojjat
authors: H
authors: Ahmadzadehfar
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D002277:Carcinoma / Q000097:blood / Q000532:radiotherapy* / Q000556:secondary*; D004151:Dipeptides / Q000627:therapeutic use*; D006573:Heterocyclic Compounds, 1-Ring / Q000627:therapeutic use*; D006801:Humans; D008187:Lutetium; D008297:Male; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D064129:Prostatic Neoplasms, Castration-Resistant / Q000097:blood* / Q000175:diagnosis / Q000532:radiotherapy*; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: C000610110:Pluvicto; D014408:Biomarkers, Tumor; D004151:Dipeptides; D006573:Heterocyclic Compounds, 1-Ring; D019275:Radiopharmaceuticals; D008187:Lutetium; D017430:Prostate-Specific Antigen
keywords: 177Lu; PSA; PSMA; prostate cancer; radioligand therapy; treatment response