title: Comparative analysis of 11 different radioisotopes for palliative treatment of bone metastases by computational methods.
abstract: OBJECTIVE
  Throughout the years, the palliative treatment of bone metastases using bone seeking radiotracers has been part of the therapeutic resources used in oncology, but the choice of which bone seeking agent to use is not consensual across sites and limited data are available comparing the characteristics of each radioisotope. Computational simulation is a simple and practical method to study and to compare a variety of radioisotopes for different medical applications, including the palliative treatment of bone metastases. This study aims to evaluate and compare 11 different radioisotopes currently in use or under research for the palliative treatment of bone metastases using computational methods.
  
  
  METHODS
  Computational models were used to estimate the percentage of deoxyribonucleic acid (DNA) damage (fast Monte Carlo damage algorithm), the probability of correct DNA repair (Monte Carlo excision repair algorithm), and the radiation-induced cellular effects (virtual cell radiobiology algorithm) post-irradiation with selected particles emitted by phosphorus-32 ((32)P), strontium-89 ((89)Sr), yttrium-90 ((90)Y ), tin-117 ((117m)Sn), samarium-153 ((153)Sm), holmium-166 ((166)Ho), thulium-170 ((170)Tm), lutetium-177 ((177)Lu), rhenium-186 ((186)Re), rhenium-188 ((188)Re), and radium-223 ((223)Ra).
  
  
  RESULTS
  (223)Ra alpha particles, (177)Lu beta minus particles, and (170)Tm beta minus particles induced the highest cell death of all investigated particles and radioisotopes. The cell survival fraction measured post-irradiation with beta minus particles emitted by (89)Sr and (153)Sm, two of the most frequently used radionuclides in the palliative treatment of bone metastases in clinical routine practice, was higher than (177)Lu beta minus particles and (223)Ra alpha particles.
  
  
  CONCLUSIONS
  (223)Ra and (177)Lu hold the highest potential for palliative treatment of bone metastases of all radioisotopes compared in this study. Data reported here may prompt future in vitro and in vivo experiments comparing different radionuclides for palliative treatment of bone metastases, raise the need for the careful rethinking of the current widespread clinical use of (89)Sr and (153)Sm, and perhaps strengthen the use of (223)Ra and (177)Lu in the palliative treatment of bone metastases.
authors.affiliation: Instituto de Engenharia Mecânica e Gestão Industrial, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465, Portugal.
authors.forename: Francisco D C
authors.initials: FD
authors.lastname: Guerra Liberal
authors.affiliation: Instituto de Engenharia Mecânica e Gestão Industrial, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465, Portugal.
authors.forename: Adriana Alexandre S
authors.initials: AA
authors.lastname: Tavares
authors.affiliation: Instituto de Engenharia Mecânica e Gestão Industrial, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465, Portugal.
authors.forename: João Manuel R S
authors.initials: JM
authors.lastname: Tavares
mesh_terms: D000465:Algorithms; D001610:Beta Particles / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry; D004249:DNA Damage; D004260:DNA Repair; D006801:Humans; D008187:Lutetium / Q000627:therapeutic use; D009010:Monte Carlo Method; D009362:Neoplasm Metastasis; D010166:Palliative Care / Q000379:methods*; D011868:Radioisotopes / Q000737:chemistry / Q000627:therapeutic use*; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D011883:Radium / Q000627:therapeutic use; D012211:Rhenium / Q000627:therapeutic use; D012493:Samarium / Q000627:therapeutic use; D013326:Strontium Radioisotopes / Q000627:therapeutic use
chemical_list: D011868:Radioisotopes; D019275:Radiopharmaceuticals; D013326:Strontium Radioisotopes; D012493:Samarium; D008187:Lutetium; D012211:Rhenium; D004247:DNA; D011883:Radium