PSA response to four series of 177Lutetium PSMA radiotherapy given over three years

June 2007, a 50 year old man underwent prostatectomy. He had prostate cancer, Gleason score 9, positive surgical margins, and bilateral lymph node metastases. Shortly afterwards he started androgen deprivation therapy. In 2011, PET/CT showed relapse in a pelvic lymph node, so he was given salvage radiotherapy. In 2014, next relapse was treated with abiraterone and a second course of salvage radiotherapy. In 2016 at next relapse, he preferred to be treated with ¹⁷⁷Lu PSMA radioligand therapy (LuPRLT) instead of docetaxel. Now August 2019, he had had four series of two cycles of LuPRLT with a cumulative ¹⁷⁷Lu activity of 48 GBq. July 2019, he was given prophylactic radiotherapy for a lumbal spine metastasis. Radiotherapy was given between two cycles of the fourth series of LuPRLT but did not give added toxicity.

Conclusions: Patients with good response to LuPRLT may respond objectively to repeat series. Repeat series of LuPRLT for metastatic prostate cancer may be as effective as repeat series of RLT for neuroendocrine tumors. Patients can be given palliative radiotherapy between cycles of LuPRLT.