Abstract
Aim: To retrospectively evaluate the feasibility of rechallenge 177Lu-Prostate-specific membrane antigen (177Lu-PSMA) radioligandtherapy (RLT). Material & Methods: Rechallenge RLT was defined as subsequent treatment with 177Lu-PSMA after initial exposure with excellent response followed by progression. Biochemical, radiographic, clinical antitumor response and adverse events were analysed. Prostate-specific antigen progression-free survival (PSA-PFS) and overall survival (OS) were calculated. Results: Eight patients underwent a median of 2 (range:1-4) cycles of 177Lu-PSMA-I&T rechallenge. Maximum PSA-decrease of 50% was achieved in 3 (37.5%) of patients. Radiographic response was favorable in 3 patients, whilst 4 exhibited progressive disease. Eastern-Cooperative-Oncology-Group (ECOG) Performance-Status was stable during therapy in all patients. No grade 4 toxicity was noticed and grade 3 toxicity occurred in 3 (37.5%) patients. The median PSA-PFS and OS were 3.2 (95%CI:2.6-3.7) and 14.0 (95%CI:6.2-21.8) months, respectively. Conclusion: In a small patient cohort with initial excellent response 177Lu-PSMA rechallenge is still active, with lower efficacy and increased toxicity levels.
- Copyright © 2018 by the Society of Nuclear Medicine and Molecular Imaging, Inc.