The Outcome and Safety of Re-challenge Lutetium-177 PSMA (¹⁷⁷Lu-PSMA) Therapy with Low-Dose Docetaxel as a...

Prostate-specific membrane antigen (PSMA)-directed radioligand therapy (PSMA-RLT) with lutetium-177 (¹⁷⁷Lu-PSMA) has been used in metastatic castrate-resistant prostate cancer (mCRPC), and retrospective data have shown this therapy to be favourably safe with attractive clinical responses. Re-challenge ¹⁷⁷Lu-PSMA therapy in early responders has been shown to be safe and effective. We report the use of low-dose Taxol-based chemotherapy (modified dose 25 mg/m² weekly × 6 weeks) as a radiosensitizer with re-challenge ¹⁷⁷Lu-PSMA therapy (4 cycles). In a period of 3 years, the patient underwent a total of 8 cycles of ¹⁷⁷Lu-PSMA with a cumulative dose of 51.8 GBq. All therapies were uneventful and well tolerated. There was a good response to re-challenge ¹⁷⁷Lu-PSMA therapy and low-dose docetaxel (Taxol-¹⁷⁷Lu-PSMA) with no recorded tumour resistance.