Theragnostics of Samarium-153-Edtmp in Patients Bearing Prostate Cancer and Osseous Secondaries: Palliative but Also Tumouricidal

Abstract

BACKGROUND: 153 The radionuclide samarium-153 ( Sm) in a chelated compound with ethylene-diamine-tetramethylene phosphonate (EDTMP) is mainly used as an alternative to palliative therapy of multifocal painful osseous metastases due to various primaries, especially 153 prostate, breast, lung cancer, and osteosarcoma. Considering novel aspects of chemical properties attributed to Sm, we aimed at evaluating the 153 outcomes of solitary versus repeated Sm-EDTMPor exclusive opiate therapy in patients with osseous secondaries from prostate cancer. MATERIALS AND METHODS: In the present retrospective study, we included three groups of patients with hormone-refractory prostate cancer (HRPC) and multiple painful osteoblastic or mixed secondaries conrmed by bone scintigraphy. Forty-three patients (Group A) received 2 153 consecutive intravenous (i.v.) administrations of Sm-EDTMP (37 MBq/kg of body weight each), twelve patients (Group B) received a solitary 153 i.v. dose Sm-EDTMP and 12 patients (Group C) used solely opiates due to exclusion criteria regarding radiometabolic therapy. RESULTS: 153 Pain palliation was reported by 90.7% of group Apatients after the second injection. The repeated dose of Sm-EDTMPimproved the duration of pain response to 24±6 versus 8±2 weeks of the single dose treatment plan, without signicant myelotoxicity. Group C patients were considered as non-responders owing to increased pain score and consumption of analgesics. CONCLUSION: 153 Arepeated-dose Sm-EDTMPtreatment scheme consistently provides enhanced pain alleviation, thereby preserving quality of 153 life in patients with skeletal metastases from HRPC. Interestingly, radiometabolic therapy with Sm-EDTMP effectuates tumouricidal implications, thus upgrading a palliative agent to a disease theragnostics-targeted modier, with anticipated survival benet.