Near-complete Response of Bilateral Adrenal Metastases to 177Lu-PSMA Therapy in Castration-resistant Prostate Cancer on Posttherapeutic SPECT-CT Follow Up

A 72-year-old man with castration-resistant prostate adenocarcinoma underwent ⁶⁸ Ga-PSMA-11 PET/CT for restaging due to significantly increased PSA levels during chemotherapy. Imaging revealed high ⁶⁸ Ga-PSMA-11 uptake in bilateral adrenal uptake, with additional uptake in the prostate and few sclerotic bone lesions. MRI and afterwards adrenal gland biopsy confirmed adrenal metastases, an uncommon metastatic site. As the patient was oligometastatic, refractory to previous systemic therapies, and ineligible for surgery or radiotherapy, ¹⁷⁷ Lu-PSMA-617 radioligand therapy was initiated. After four treatment cycles, PSA levels progressively decreased, and post-therapeutic follow-up SPECT/CT demonstrated a near-complete response in adrenal and bone metastases without treatment-related adverse effects.