Combined [ 223 Ra]Radiumdichloride and [ 177 Lu]Lu-PSMA-617 Therapy in End-stage Metastatic Castration-resistant...

Area of Science:

• Nuclear Medicine
• Oncology
• Radiopharmaceutical Therapy

Background:

• Metastatic castration-resistant prostate cancer (mCRPC) presents significant treatment challenges.
• Dual alpha/beta radionuclide therapy offers a novel therapeutic approach.

Purpose of the Study:

• To present a case of advanced mCRPC treated with combined [177Lu]Lu-PSMA-617 and [223Ra]Radiumdichloride.
• To evaluate the feasibility, safety, and response to this dual radionuclide regimen.

Main Methods:

• A single patient with heavily pretreated mCRPC received combined [177Lu]Lu-PSMA-617 and [223Ra]Radiumdichloride therapy.
• Treatment response was assessed through serial imaging (including FDG-PET) and serologic markers (PSA, alkaline phosphatase).
• Tolerability was monitored using CTCAE criteria.

Main Results:

• The combined regimen was generally well-tolerated, with mild xerostomia and fatigue (CTCAE 1), and moderate anemia (CTCAE 2).
• Initial evaluations showed a favorable response with biochemical and imaging improvements.
• Subsequent progression was observed, characterized by dedifferentiated pelvic recurrence, FDG-avid osseous lesions, and PSMA-negative lymph node metastases.

Conclusions:

• Combined [177Lu]Lu-PSMA-617 and [223Ra]Radiumdichloride therapy is feasible and safe in heavily pretreated mCRPC patients.
• This case illustrates a pattern of initial response followed by disease progression, highlighting the complex behavior of mCRPC under dual radionuclide treatment.
• Further investigation is warranted to understand long-term efficacy and resistance mechanisms.