The Outcome and Safety of Re-challenge Lutetium-177 PSMA (177Lu-PSMA) Therapy with Low-Dose Docetaxel as a Radiosensitizer—a Promising Combination in Metastatic Castrate-Resistant Prostate Cancer (mCRPC): a Case Report

Prostate-specific membrane antigen (PSMA)-directed radioligand therapy (PSMA-RLT) with lutetium-177 ( 177 Lu-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 177 Lu-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/m 2 weekly × 6 weeks) as a radiosensitizer with re-challenge 177 Lu-PSMA therapy (4 cycles). In a period of 3 years, the patient underwent a total of 8 cycles of 177 Lu-PSMA with a cumulative dose of 51.8 GBq. All therapies were uneventful and well tolerated. There was a good response to re-challenge 177 Lu-PSMA therapy and low-dose docetaxel (Taxol- 177 Lu-PSMA) with no recorded tumour resistance.