Abstract
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Objectives Radio labeled prostate specific membrane antigen (PSMA) ligands represent a true theranostics concept in diagnostic and therapy of relapsed and metastatic prostate cancer patients. The aim of this study was to evaluate response and tolerability of a single dose of 177Lutetium-PSMA-617 (Lu-PSMA) in a larger cohort of patients with metastatic castration resistant prostate cancer (mCRPC).
Methods The data of 82 consecutive patients with metastatic castration resistant prostate cancer who received a single dose of Lu-PSMA at baseline and 8 weeks later were analyzed retrospectively. 68Ga-PSMA-11 PET/CT was performed in all patients to verify sufficient PSMA expression. Bones, lymph node, lung and liver metastases were present in 99%, 65%, 11% and 17% of the patients. Tolerability and response were evaluated according haematologic parameters, renal scintigraphy, clinical data and PSA value (according to prostate cancer work group 2) at baseline and 8 weeks after therapy application.
Results Data of 74 patients were available for analysis. A total of six patients died and two patients dropped out not willing to continue therapy and follow-up. 47 (64%) of the patients showed a PSA-Decline, of these 23 (31%) had a PSA decline > 50%, 35 (47%) had a stable disease with a PSA decline from <50% to an increase <25% and 17 (23%) showed a progressive disease with a PSA increase >25%. There were no significant changes of median values in haemoglobin, white blood cells, creatinine and tubular extraction rates. There was a significant decline in platelets compared to baseline, however still with a median value within the normal range.
Conclusions Radio ligand therapy with 177Lu-PSMA-617 is safe, well tolerated and shows considerable response in PSA values as salvage therapy in patients with mCRPC.