Independent technique of verifying high-dose rate (HDR) brachytherapy treatment plans.
OBJECTIVE
An independent technique for verifying high-dose rate (HDR) brachytherapy treatment plans has been formulated and validated clinically.


METHODS
In HDR brachytherapy, dwell times at respective dwell positions are computed, using an optimization algorithm in a HDR treatment-planning system to deliver a specified dose to many target points simultaneously. Because of the variability of dwell times, concerns have been expressed regarding the ability of the algorithm to compute the correct dose. To address this concern, a commercially available low-dose rate (LDR) algorithm was used to compute the doses at defined distances, based on the dwell times obtained from the HDR treatment plans. The percent deviation between doses computed using the HDR and LDR algorithms were reviewed for HDR procedures performed over the last year.


RESULTS
In this retrospective study, the difference between computed doses using the HDR and LDR algorithms was found to be within 5% for about 80% of the HDR procedures. All of the reviewed procedures have dose differences of less than 10%.


CONCLUSIONS
An independent technique for verifying HDR brachytherapy treatment plans has been validated based on clinical data. Provided both systems are available, this technique is universal in its applications and not limited to either a particular implant applicator, implant site, or implant type.
Saw
C B
CB
Division of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City 52242, USA.
Korb
L J
LJ
Darnell
B
B
Krishna
K V
KV
Ulewicz
D
D
D000465:Algorithms; D001918:Brachytherapy; D006801:Humans; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies