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A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer

BACKGROUND AND PURPOSE: Urethra-sparing radiation therapy for localized prostate cancer can reduce the risk of radiation-induced genitourinary toxicity by intentionally underdosing the periurethral transitional zone. We aimed to compare the clinical impact of a urethra-sparing intensity-modulated pr...

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Autores principales: Yoshimura, Takaaki, Nishioka, Kentaro, Hashimoto, Takayuki, Seki, Kazuya, Kogame, Shouki, Tanaka, Sodai, Kanehira, Takahiro, Tamura, Masaya, Takao, Seishin, Matsuura, Taeko, Kobashi, Keiji, Kato, Fumi, Aoyama, Hidefumi, Shimizu, Shinichi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8517200/
https://www.ncbi.nlm.nih.gov/pubmed/34693040
http://dx.doi.org/10.1016/j.phro.2021.09.006
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author Yoshimura, Takaaki
Nishioka, Kentaro
Hashimoto, Takayuki
Seki, Kazuya
Kogame, Shouki
Tanaka, Sodai
Kanehira, Takahiro
Tamura, Masaya
Takao, Seishin
Matsuura, Taeko
Kobashi, Keiji
Kato, Fumi
Aoyama, Hidefumi
Shimizu, Shinichi
author_facet Yoshimura, Takaaki
Nishioka, Kentaro
Hashimoto, Takayuki
Seki, Kazuya
Kogame, Shouki
Tanaka, Sodai
Kanehira, Takahiro
Tamura, Masaya
Takao, Seishin
Matsuura, Taeko
Kobashi, Keiji
Kato, Fumi
Aoyama, Hidefumi
Shimizu, Shinichi
author_sort Yoshimura, Takaaki
collection PubMed
description BACKGROUND AND PURPOSE: Urethra-sparing radiation therapy for localized prostate cancer can reduce the risk of radiation-induced genitourinary toxicity by intentionally underdosing the periurethral transitional zone. We aimed to compare the clinical impact of a urethra-sparing intensity-modulated proton therapy (US-IMPT) plan with that of conventional clinical plans without urethral dose reduction. MATERIALS AND METHODS: This study included 13 patients who had undergone proton beam therapy. The prescribed dose was 63 GyE in 21 fractions for 99% of the clinical target volume. To compare the clinical impact of the US-IMPT plan with that of the conventional clinical plan, tumor control probability (TCP) and normal tissue complication probability (NTCP) were calculated with a generalized equivalent uniform dose-based Lyman–Kutcher model using dose volume histograms. The endpoints of these model parameters for the rectum, bladder, and urethra were fistula, contraction, and urethral stricture, respectively. RESULTS: The mean NTCP value for the urethra in US-IMPT was significantly lower than that in the conventional clinical plan (0.6% vs. 1.2%, p < 0.05). There were no statistically significant differences between the conventional and US-IMPT plans regarding the mean minimum dose for the urethra with a 3-mm margin, TCP value, and NTCP value for the rectum and bladder. Additionally, the target dose coverage of all plans in the robustness analysis was within the clinically acceptable range. CONCLUSIONS: Compared with the conventional clinically applied plans, US-IMPT plans have potential clinical advantages and may reduce the risk of genitourinary toxicities, while maintaining the same TCP and NTCP in the rectum and bladder.
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spelling pubmed-85172002021-10-21 A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer Yoshimura, Takaaki Nishioka, Kentaro Hashimoto, Takayuki Seki, Kazuya Kogame, Shouki Tanaka, Sodai Kanehira, Takahiro Tamura, Masaya Takao, Seishin Matsuura, Taeko Kobashi, Keiji Kato, Fumi Aoyama, Hidefumi Shimizu, Shinichi Phys Imaging Radiat Oncol Original Research Article BACKGROUND AND PURPOSE: Urethra-sparing radiation therapy for localized prostate cancer can reduce the risk of radiation-induced genitourinary toxicity by intentionally underdosing the periurethral transitional zone. We aimed to compare the clinical impact of a urethra-sparing intensity-modulated proton therapy (US-IMPT) plan with that of conventional clinical plans without urethral dose reduction. MATERIALS AND METHODS: This study included 13 patients who had undergone proton beam therapy. The prescribed dose was 63 GyE in 21 fractions for 99% of the clinical target volume. To compare the clinical impact of the US-IMPT plan with that of the conventional clinical plan, tumor control probability (TCP) and normal tissue complication probability (NTCP) were calculated with a generalized equivalent uniform dose-based Lyman–Kutcher model using dose volume histograms. The endpoints of these model parameters for the rectum, bladder, and urethra were fistula, contraction, and urethral stricture, respectively. RESULTS: The mean NTCP value for the urethra in US-IMPT was significantly lower than that in the conventional clinical plan (0.6% vs. 1.2%, p < 0.05). There were no statistically significant differences between the conventional and US-IMPT plans regarding the mean minimum dose for the urethra with a 3-mm margin, TCP value, and NTCP value for the rectum and bladder. Additionally, the target dose coverage of all plans in the robustness analysis was within the clinically acceptable range. CONCLUSIONS: Compared with the conventional clinically applied plans, US-IMPT plans have potential clinical advantages and may reduce the risk of genitourinary toxicities, while maintaining the same TCP and NTCP in the rectum and bladder. Elsevier 2021-10-08 /pmc/articles/PMC8517200/ /pubmed/34693040 http://dx.doi.org/10.1016/j.phro.2021.09.006 Text en © 2021 The Author(s) https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Original Research Article
Yoshimura, Takaaki
Nishioka, Kentaro
Hashimoto, Takayuki
Seki, Kazuya
Kogame, Shouki
Tanaka, Sodai
Kanehira, Takahiro
Tamura, Masaya
Takao, Seishin
Matsuura, Taeko
Kobashi, Keiji
Kato, Fumi
Aoyama, Hidefumi
Shimizu, Shinichi
A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer
title A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer
title_full A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer
title_fullStr A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer
title_full_unstemmed A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer
title_short A treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer
title_sort treatment planning study of urethra-sparing intensity-modulated proton therapy for localized prostate cancer
topic Original Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8517200/
https://www.ncbi.nlm.nih.gov/pubmed/34693040
http://dx.doi.org/10.1016/j.phro.2021.09.006
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