Calculation of the 3-D dose distribution surrounding a 103Pd stent.
OBJECTIVE
This study was designed to assess the suitability of a 103Pd-implanted stent for use in intravascular brachytherapy.


METHODS
A stent was modeled as a superposition of 201 identical struts and the EGS4/DOSRZ Monte Carlo code was used to calculate the dose distribution for each strut. To verify the simulation parameters, doses along the transverse axis of a Model 200 103Pd interstitial seed were calculated and compared to those calculated by the TG43 method.


RESULTS
Dose profiles within 1 mm of the stent's outer surface were heterogeneous and reflected the stent's structure. For a 2-mm outer-diameter 103Pd-implanted stent, approximately 2.68 x 10(7) Bq were required to deliver 31.5 Gy in 28 days at a distance of 0.5 mm along the perpendicular bisector from the stent's outer surface. The Monte Carlo simulation of the 103Pd seed showed relative doses within 7% of the values calculated by the TG43 method.


CONCLUSIONS
The dosimetry about a 103Pd-implanted stent suggests that the stent is suitable for use in intravascular brachytherapy.
McLemore
L B
LB
Department of Radiation Physics, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
Horton
J L
JL
Antolak
J A
JA
D001918:Brachytherapy; D006801:Humans; D021621:Imaging, Three-Dimensional; D009010:Monte Carlo Method; D010165:Palladium / Q000627:therapeutic use*; D011868:Radioisotopes / Q000627:therapeutic use*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D015607:Stents; D014867:Water
D011868:Radioisotopes; D014867:Water; D010165:Palladium