Background 177Lu-prostate-specific-membrane antigen (PSMA) radioligand therapy is effective for patients with advanced prostate cancer but has mainly used after failure to established systemic therapies.
Aim: To analyze effects and adverse effects of 177Lu-PSMA-617 radioligand therapy for patients with prostate cancer and metastases in only lymph nodes.
Methods: The study addressed two end-points for effects of the treatment: the change of prostate specific antigen (PSA) and findings in follow-up 68Ga-PSMA PET/CT. Adverse effects were evaluated according to international classification. All statistical analyses were performed with Stata 14.2.
Results: Twenty-four patients with lymph node metastases started 177 Lu-PSMA radioligand therapy between April 2013 and February 2017. Fourteen of the patients had been failures to established treatments for metastatic prostate cancer such as salvage radiotherapy, abiraterone, enzalutamide, and docetaxel. 177Lu-PSMA radioligand therapy was given with median three cycles (range 1 to 5 cycles). The first three cycles had a median radioactivity of 5.5, 5.8, and 6.9 GBq, respectively. The cycles were given with two months interval. Median change of pre-treatment PSA was a 67% reduction. Twelve of 24 evaluable patients (50%) had an >50% PSA reduction. 177Lu-PSMA-617 radioligand therapy had mild and transitory adverse effects. For one patient, the high number of cycles reflected restart with a fifth cycle of the radioligand therapy due to biochemical progression observed in follow-up after the first series of four cycles.
Conclusion: For patients with lymph node metastatic prostate cancer, 177Lu-PSMA radioligand therapy was effective and safe.
