TY - JOUR
T1 - Live implant dosimetry may be an effective replacement for postimplant computed tomography in localized prostate cancer patients receiving low dose rate brachytherapy
AU - Roshan, D.
AU - Joyce, K.
AU - Woulfe, P.
AU - Gorakati, P.R.
AU - Stock, R.
AU - Sullivan, F.J.
N1 - Publisher Copyright:
© 2021 American Brachytherapy Society
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Purpose: To determine if Live Implant Dosimetry (LIDO) utilizing intraoperative transrectal ultrasound (TRUS) is equivalent to postimplant CT dosimetry (either day 0 or day 30) in patients with localized prostate cancer (PC) treated with low dose rate (LDR) prostate seed brachytherapy. Methods and Materials: The treated population consisted of 628 men with localized (T1-T2) PC. All d'Amico risk categories (low, intermediate, and high) were included, and 437 patients were treated with monotherapy (160 Gy) [low and low tier intermediate], and the remainder (191) [high tier intermediate and high risk] with an implant boost (106 Gy) post external beam radiation, to a volume including the prostate and seminal vesicles (46 Gy). LIDO with intraoperative TRUS, postimplant CT (day 0 and day 30) were performed in all cases. Prostate volumes (V), V
100 (prostate) and dose (D) D
90 (prostate), D
30 (urethra), and Rectum D
2cc, were recorded. No urinary catheter was used on Day 30 CT. Results: More than 91.33% of monotherapy patients reached the target D
90 according to LIDO while only 82.99% of Day 0 CT and 92.82% of Day 30 CT achieved target D
90. When considering V
100, monotherapy patients recorded target dosimetry in 90.93%, 82.31%, and 92.02% of cases assessed by LIDO, Day 0 CT and Day 30 CT, respectively. Strong correlations are observed in D
90, Rectum D
2cc and Urethra D
30 across imaging modalities but V
100 and V
150 were poorly correlated due to the relative quantification of this parameter and high degree of error in measurement. Of all monotherapy patients with satisfactory dosimetry on LIDO, 94.82% reached target D
90 at day 30 CT and 94.19% reached target V
100. Conclusions: LIDO and CT are both effective tools for assessing postimplant dosimetry. Patients with satisfactory LIDO dosimetry are highly likely to have equivalent dosimetry on CT at follow-up, indicating that postimplant CT may be eliminated in PC a patients implanted with this technique.
AB - Purpose: To determine if Live Implant Dosimetry (LIDO) utilizing intraoperative transrectal ultrasound (TRUS) is equivalent to postimplant CT dosimetry (either day 0 or day 30) in patients with localized prostate cancer (PC) treated with low dose rate (LDR) prostate seed brachytherapy. Methods and Materials: The treated population consisted of 628 men with localized (T1-T2) PC. All d'Amico risk categories (low, intermediate, and high) were included, and 437 patients were treated with monotherapy (160 Gy) [low and low tier intermediate], and the remainder (191) [high tier intermediate and high risk] with an implant boost (106 Gy) post external beam radiation, to a volume including the prostate and seminal vesicles (46 Gy). LIDO with intraoperative TRUS, postimplant CT (day 0 and day 30) were performed in all cases. Prostate volumes (V), V
100 (prostate) and dose (D) D
90 (prostate), D
30 (urethra), and Rectum D
2cc, were recorded. No urinary catheter was used on Day 30 CT. Results: More than 91.33% of monotherapy patients reached the target D
90 according to LIDO while only 82.99% of Day 0 CT and 92.82% of Day 30 CT achieved target D
90. When considering V
100, monotherapy patients recorded target dosimetry in 90.93%, 82.31%, and 92.02% of cases assessed by LIDO, Day 0 CT and Day 30 CT, respectively. Strong correlations are observed in D
90, Rectum D
2cc and Urethra D
30 across imaging modalities but V
100 and V
150 were poorly correlated due to the relative quantification of this parameter and high degree of error in measurement. Of all monotherapy patients with satisfactory dosimetry on LIDO, 94.82% reached target D
90 at day 30 CT and 94.19% reached target V
100. Conclusions: LIDO and CT are both effective tools for assessing postimplant dosimetry. Patients with satisfactory LIDO dosimetry are highly likely to have equivalent dosimetry on CT at follow-up, indicating that postimplant CT may be eliminated in PC a patients implanted with this technique.
KW - D2cc(rectum)
KW - D30(urethra)
KW - D90
KW - LDR brachytherapy
KW - Live implant dosimetry
KW - Postimplant dosimetry
KW - Prostate cancer
KW - V100
UR - https://www.scopus.com/pages/publications/85103957226
U2 - 10.1016/j.brachy.2021.02.008
DO - 10.1016/j.brachy.2021.02.008
M3 - Article
SN - 1538-4721
VL - 20
SP - 873
EP - 882
JO - Brachytherapy
JF - Brachytherapy
IS - 4
ER -
