Abstract Patients with metastatic castration-resistant prostate cancer usually have lymph nodes and bone metastasis. We present a rare case of a 51-year-old patient with metastatic castration-resistant prostate cancer who complained of left truncated sciatica and diffuse bone pain and who was referred for 177 Lu-prostate-specific membrane antigen (PSMA) screening. Pretreatment 68 Ga-PSMA showed left sciatic nerve and multiple bone uptake. Patient underwent stereotactic radiotherapy on the sciatic nerve metastasis (30 Gy in 6 fractions of 5 Gy) before 7.4 GBq of 177 Lu-PSMA infusions. Left truncated sciatica disappeared after stereotactic radiotherapy. No additional toxicity was added to the sciatic nerve from 177 Lu-PSMA after stereotactic radiotherapy.