The hybrid imaging modalities - ⁶⁸Ga PSMA PET/CT and ^99mTc MDP SPECT/CT for the therapeutic management of patients with prostate carcinoma treated with Radium 223 in Bulgaria

More than 90% of the patients with mCRPC present with radiologically proven bone metastases, which is the main cause of death and poor quality of life. Available osteotropic agents have not shown improvement in survival in these patients. Radium-223 dichloride (Radium-223) is the first osteoptropic therapeutic agent that significantly extends the overall survival of patients with CRPC and metastatic bone disease. The aim of this study is to present our first impression from the use of Radium-223 in patients with symptomatic bone metastases from mCRPC, as well as the application of various hybrid imaging methods for staging and evaluation of the therapeutic effect. For a period of 18 months, four patients with bone lesions from CRPC were treated with Radium-223 dichloride at the Clinic of Nuclear Medicine at the University Hospital 'Alexandrovska'. The therapeutic response evaluation is based on the clinical and imaging data, including the use of the prostate total score and the EuroQoL 5D utility. All patients received an incomplete course of treatment with four to five intravenous Radium-223. After re-staging, one of the patients had a complete metabolic and morphologic response, two of them - partial therapeutic effect, and one - radiological progression. Two of the treated patients developed II gr. anemia and II gr, thrombocytopenia as an undesirable side effect. All patients reported an improvement in the pain symptoms. Regardless of the small number of patients and the non-linear results of Radium-223 application in Bulgaria, the latter offers hope for its effective application after achieving complete or partial morphological response in three of the treated patients, as well as a complete improvement in regard of symptoms and quality of life for all treated patients.