TY - JOUR
T1 - Simultaneous needle catheter selection and dwell time optimization for preplanning of high-dose-rate brachytherapy of prostate cancer
AU - Wang, Chao
AU - Gonzalez, Yesenia
AU - Shen, Chenyang
AU - Hrycushko, Brian
AU - Jia, Xun
N1 - Publisher Copyright:
© 2021 Institute of Physics and Engineering in Medicine.
PY - 2021/3/7
Y1 - 2021/3/7
N2 - Purpose. Needle catheter positions critically affect the quality of treatment plans in prostate cancer high-dose-rate (HDR) brachytherapy. The current standard needle positioning approach is based on human intuition, which cannot guarantee a high-quality plan. This study proposed a method to simultaneously select needle catheter positions and determine dwell time for preplanning of HDR brachytherapy of prostate cancer. Methods. We formulated the needle catheter selection problem and inverse dwell time optimization problem in a unified framework. In addition to the dose objectives of the planning target volume (PTV) and organs at risk (OARs), the objective function incorporated a group-sparsity term with a needle-specific adaptive weighting scheme to generate high-quality plans with the minimal number of needle catheters. The optimization problem was solved by a fast-iterative shrinkage-thresholding algorithm. For validation purposes, we tested the proposed algorithm on 10 patient cases previously treated at our institution and compared the resulting plans with plans generated using needle catheters selected manually. Results. Compared to the plan with manually selected needle catheters, when normalizing both plans to the same PTV coverage V 100% = 95%, the plans generated by the proposed algorithm reduced median V 125% from 65% to 64%, but increased median V 150% from 35% to 38%, and V 200% from 14% to 16%. All planning objectives were met. All clinically important dosimetric parameters of OARs were reduced. D 1cc of bladder and rectum were reduced from 8.57 Gy to 8.50 Gy and from 7.24 Gy to 6.80 Gy, respectively. D max of urethra was reduced from 15.85 Gy to 15.77 Gy. The median number of selected needle catheters was reduced by two. The computational time for solving the proposed optimization problem was ∼90 s using MATLAB. Conclusion. The proposed algorithm was able to generate plans for prostate cancer HDR brachytherapy preplanning with increased median conformity index (0.73-0.77) and slightly lower median homogeneity index (0.64-0.62) with the number of selected needles reduced by two compared to the manual needle selection approach.
AB - Purpose. Needle catheter positions critically affect the quality of treatment plans in prostate cancer high-dose-rate (HDR) brachytherapy. The current standard needle positioning approach is based on human intuition, which cannot guarantee a high-quality plan. This study proposed a method to simultaneously select needle catheter positions and determine dwell time for preplanning of HDR brachytherapy of prostate cancer. Methods. We formulated the needle catheter selection problem and inverse dwell time optimization problem in a unified framework. In addition to the dose objectives of the planning target volume (PTV) and organs at risk (OARs), the objective function incorporated a group-sparsity term with a needle-specific adaptive weighting scheme to generate high-quality plans with the minimal number of needle catheters. The optimization problem was solved by a fast-iterative shrinkage-thresholding algorithm. For validation purposes, we tested the proposed algorithm on 10 patient cases previously treated at our institution and compared the resulting plans with plans generated using needle catheters selected manually. Results. Compared to the plan with manually selected needle catheters, when normalizing both plans to the same PTV coverage V 100% = 95%, the plans generated by the proposed algorithm reduced median V 125% from 65% to 64%, but increased median V 150% from 35% to 38%, and V 200% from 14% to 16%. All planning objectives were met. All clinically important dosimetric parameters of OARs were reduced. D 1cc of bladder and rectum were reduced from 8.57 Gy to 8.50 Gy and from 7.24 Gy to 6.80 Gy, respectively. D max of urethra was reduced from 15.85 Gy to 15.77 Gy. The median number of selected needle catheters was reduced by two. The computational time for solving the proposed optimization problem was ∼90 s using MATLAB. Conclusion. The proposed algorithm was able to generate plans for prostate cancer HDR brachytherapy preplanning with increased median conformity index (0.73-0.77) and slightly lower median homogeneity index (0.64-0.62) with the number of selected needles reduced by two compared to the manual needle selection approach.
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U2 - 10.1088/1361-6560/abd00e
DO - 10.1088/1361-6560/abd00e
M3 - Article
C2 - 33264753
AN - SCOPUS:85102413894
SN - 0031-9155
VL - 66
JO - Physics in medicine and biology
JF - Physics in medicine and biology
IS - 5
M1 - 055028
ER -