title: A case report of image-based dosimetry of bone metastases with Alpharadin ((223)Ra-dichloride) therapy: inter-fraction variability of absorbed dose and follow-up.
abstract: A 70-year-old man affected by bone metastases from castration resistant prostate cancer underwent Alpharadin ((223)Ra-dichloride) therapy (6 administrations of 50 kBq per kg i.v., once every 4 weeks). The inter-fraction variability of the absorbed dose to lesions was evaluated for four injections. Dosimetric assessments were performed following the MIRD approach and a recently published methodology. The mean absorbed dose and standard deviation for 4 lesions [mean (σ %)] were: 434 mGy (15%) and 516 mGy (21%) for the right and left humeral head, 1205 mGy (14%) and 781 mGy (8%) for the right and left glenoid. The estimated total absorbed dose after the whole treatment, considering also the relative-biological effectiveness of alpha particles (RBE = 5), yielded a D RBE range of 13-36 Gy. A good correlation between (99m)Tc and (223)Ra uptake was obtained (R (2) = 0.7613). The tumour-non-tumour (TNT) ratio of 8 lesions (those above, plus 4 additional), monitored by six (99m)Tc-MDP bone scans over a period of about 10 months, evidenced a TNT reduction in two lesions (-42 and -48 %), but in most lesions the TNT remained fairly constant, evidencing that (223)Ra-dichloride therapy tends to prevent further progression of osseous disease, leading to chronicity of the metastatic status.
authors.affiliation: Department of Medical Physics, Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense No. 87, 00152, Rome, Italy. mpacilio@scamilloforlanini.rm.it.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Pacilio
authors.affiliation: Department of Nuclear Medicine, Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense No. 87, 00152, Rome, Italy. gventroni@scamilloforlanini.rm.it.
authors.forename: Guido
authors.initials: G
authors.lastname: Ventroni
authors.affiliation: Health Physics Postgraduate School, "Sapienza" University of Rome, Piazzale Aldo Moro No. 5, 00185, Rome, Italy. bartolomeo.cassano@gmail.com.
authors.forename: Bartolomeo
authors.initials: B
authors.lastname: Cassano
authors.affiliation: Department of Radiology, Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense No. 87, 00152, Rome, Italy. PIalongo@scamilloforlanini.rm.it.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Ialongo
authors.affiliation: Health Physics Postgraduate School, "Sapienza" University of Rome, Piazzale Aldo Moro No. 5, 00185, Rome, Italy. lorenzon.leda88@gmail.com.
authors.forename: Leda
authors.initials: L
authors.lastname: Lorenzon
authors.affiliation: Department of Radiological, Oncological and Anatomo Pathological Sciences, "Sapienza" University of Rome, Viale Del Policlinico No. 155, 00161, Rome, Italy. e.dicastro@policlinicoumberto1.it.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Di Castro
authors.affiliation: Department of Medical Oncology, Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense No. 87, 00152, Rome, Italy. recinefederica@gmail.com.
authors.forename: Federica
authors.initials: F
authors.lastname: Recine
authors.affiliation: Department of Medical Oncology, Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense No. 87, 00152, Rome, Italy. CSternberg@scamilloforlanini.rm.it.
authors.forename: Cora N
authors.initials: CN
authors.lastname: Sternberg
authors.affiliation: Department of Nuclear Medicine, Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense No. 87, 00152, Rome, Italy. lmango@scamilloforlanini.rm.it.
authors.forename: Lucio
authors.initials: L
authors.lastname: Mango
mesh_terms: D000368:Aged; D001859:Bone Neoplasms / Q000532:radiotherapy* / Q000556:secondary*; D002712:Chlorides / Q000627:therapeutic use*; D019583:Dose Fractionation, Radiation; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D064129:Prostatic Neoplasms, Castration-Resistant / Q000473:pathology; D011874:Radiometry; D011883:Radium / Q000627:therapeutic use*
chemical_list: D002712:Chlorides; D011883:Radium
keywords: 223Ra-dichloride; Bone metastases; Dosimetry; Radionuclide therapy