Selective identification of different brachytherapy sources, ferromagnetic seeds, and fiducials in the prostate using an automated seed sorting algorithm.
OBJECTIVE
Routine permanent prostate brachytherapy (PPB) includes CT-based postimplant dosimetry (PID). A method of identifying different source types from CT data in the same implant volume is described.


METHODS
A previously described automatic method for seed localization using CT data is used in this study. Two cases were analyzed: a PPB case with (103)Pd followed by salvage (125)I implantation, both performed at another institution, and a cadaver case where 4 different seed types, including ferromagnetic seeds, and fiducials were implanted.


RESULTS
Automatic segregation of different seed types with minimal manual correction is demonstrated using the described localization algorithm. The process is confirmed accurate by comparison of plain film radiographs to CT data and digitally reconstructed radiographs.


CONCLUSIONS
Unique identification of different source types, including PPB seeds, fiducial markers, and ferromagnetic seeds in permanent implants is possible and permits dosimetric analyses that are spatially coincident.
Davis
Brian J
BJ
Division of Radiation Oncology, Mayo Clinic and Foundation, 200 First Street, SW Rochester, MN 55905, USA. davis.brian@mayo.edu
Brinkmann
Debra H
DH
Kruse
Jon J
JJ
Herman
Michael G
MG
LaJoie
Wayne N
WN
Schwartz
David J
DJ
Pisansky
Thomas M
TM
Kline
Robert W
RW
D000368:Aged; D000465:Algorithms; D001918:Brachytherapy / Q000295:instrumentation*; D005290:Ferric Compounds / Q000627:therapeutic use*; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D008297:Male; D010165:Palladium / Q000627:therapeutic use; D010388:Pelvis / Q000000981:diagnostic imaging; D011467:Prostate / Q000000981:diagnostic imaging* / Q000528:radiation effects; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011868:Radioisotopes / Q000627:therapeutic use; D016879:Salvage Therapy; D014057:Tomography, X-Ray Computed
D005290:Ferric Compounds; D007496:Iridium Radioisotopes; D011868:Radioisotopes; C001215:ferrite; D010165:Palladium