Variability of treatment planning of seed implantation: A Japanese multicenter simulation study

Hiromichi Ishiyama, Masahiro Nakano, Kazuhito Toya, Ryuichi Kota, Koyo Kikuchi, Takahiro Yamaguchi, Naoaki Kono, Shogo Kawakami, Yuki Tsutsumi, Tomoki Tanaka, Takahisa Eriguchi, Saiji Ohga, Toshihiro Yamaguchi, Yoshiaki Takakawa, Masashi Morita, Norihisa Katayama, Toshio Ohashi, Manabu Aoki, Atsunori Yorozu, Siro Saito

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Purpose: This multicenter study was conducted to evaluate the current variability of treatment planning of seed implantation in Japanese centers and the feasibility of two virtual trials. Methods and Materials: Two types of contour data were sent to 12 radiation oncologists with a request letter that asked them to make treatment plans on the data in the same manner as in their own practice. Five of the 12 radiation oncologists were asked to participate in the two virtual trials in which the D90 (dose to the hottest 90% of prostate volume) was 1) required to be set at just 180 Gy and 2) increased as much as possible without violating other limitations. Results: A relatively high dose with a small deviation was irradiated to the prostate in Japanese centers (mean D90 = 188 Gy; SD = 10 Gy). In the virtual trials, all five physicians could achieve 180 Gy for the D90 with a very small deviation, although the urethral dose showed relatively large deviations. Dose escalation without increase of urethral dose or V150 was difficult, although the rectum could be spared by most of the physicians. Conclusion: Our study showed a relatively high dose with a small deviation was prescribed to the prostate in Japanese centers. Consolidated protocols such as D90 = 180 Gy could be available for future trials. Meanwhile, our study suggested that some cautions might be needed for urethral dose and the V150, even when a relatively low D90 was requested.

Original languageEnglish
JournalBrachytherapy
DOIs
Publication statusAccepted/In press - Feb 21 2017

Fingerprint

Multicenter Studies
Prostate
Seeds
Physicians
Rectum
Therapeutics
Radiation Oncologists

Keywords

  • Brachytherapy
  • Low-dose-rate
  • Prostate cancer
  • Treatment plan
  • Variability

ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging

Cite this

Ishiyama, H., Nakano, M., Toya, K., Kota, R., Kikuchi, K., Yamaguchi, T., ... Saito, S. (Accepted/In press). Variability of treatment planning of seed implantation: A Japanese multicenter simulation study. Brachytherapy. https://doi.org/10.1016/j.brachy.2017.05.007

Variability of treatment planning of seed implantation : A Japanese multicenter simulation study. / Ishiyama, Hiromichi; Nakano, Masahiro; Toya, Kazuhito; Kota, Ryuichi; Kikuchi, Koyo; Yamaguchi, Takahiro; Kono, Naoaki; Kawakami, Shogo; Tsutsumi, Yuki; Tanaka, Tomoki; Eriguchi, Takahisa; Ohga, Saiji; Yamaguchi, Toshihiro; Takakawa, Yoshiaki; Morita, Masashi; Katayama, Norihisa; Ohashi, Toshio; Aoki, Manabu; Yorozu, Atsunori; Saito, Siro.

In: Brachytherapy, 21.02.2017.

Research output: Contribution to journalArticle

Ishiyama, H, Nakano, M, Toya, K, Kota, R, Kikuchi, K, Yamaguchi, T, Kono, N, Kawakami, S, Tsutsumi, Y, Tanaka, T, Eriguchi, T, Ohga, S, Yamaguchi, T, Takakawa, Y, Morita, M, Katayama, N, Ohashi, T, Aoki, M, Yorozu, A & Saito, S 2017, 'Variability of treatment planning of seed implantation: A Japanese multicenter simulation study', Brachytherapy. https://doi.org/10.1016/j.brachy.2017.05.007
Ishiyama, Hiromichi ; Nakano, Masahiro ; Toya, Kazuhito ; Kota, Ryuichi ; Kikuchi, Koyo ; Yamaguchi, Takahiro ; Kono, Naoaki ; Kawakami, Shogo ; Tsutsumi, Yuki ; Tanaka, Tomoki ; Eriguchi, Takahisa ; Ohga, Saiji ; Yamaguchi, Toshihiro ; Takakawa, Yoshiaki ; Morita, Masashi ; Katayama, Norihisa ; Ohashi, Toshio ; Aoki, Manabu ; Yorozu, Atsunori ; Saito, Siro. / Variability of treatment planning of seed implantation : A Japanese multicenter simulation study. In: Brachytherapy. 2017.
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abstract = "Purpose: This multicenter study was conducted to evaluate the current variability of treatment planning of seed implantation in Japanese centers and the feasibility of two virtual trials. Methods and Materials: Two types of contour data were sent to 12 radiation oncologists with a request letter that asked them to make treatment plans on the data in the same manner as in their own practice. Five of the 12 radiation oncologists were asked to participate in the two virtual trials in which the D90 (dose to the hottest 90{\%} of prostate volume) was 1) required to be set at just 180 Gy and 2) increased as much as possible without violating other limitations. Results: A relatively high dose with a small deviation was irradiated to the prostate in Japanese centers (mean D90 = 188 Gy; SD = 10 Gy). In the virtual trials, all five physicians could achieve 180 Gy for the D90 with a very small deviation, although the urethral dose showed relatively large deviations. Dose escalation without increase of urethral dose or V150 was difficult, although the rectum could be spared by most of the physicians. Conclusion: Our study showed a relatively high dose with a small deviation was prescribed to the prostate in Japanese centers. Consolidated protocols such as D90 = 180 Gy could be available for future trials. Meanwhile, our study suggested that some cautions might be needed for urethral dose and the V150, even when a relatively low D90 was requested.",
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AU - Kikuchi, Koyo

AU - Yamaguchi, Takahiro

AU - Kono, Naoaki

AU - Kawakami, Shogo

AU - Tsutsumi, Yuki

AU - Tanaka, Tomoki

AU - Eriguchi, Takahisa

AU - Ohga, Saiji

AU - Yamaguchi, Toshihiro

AU - Takakawa, Yoshiaki

AU - Morita, Masashi

AU - Katayama, Norihisa

AU - Ohashi, Toshio

AU - Aoki, Manabu

AU - Yorozu, Atsunori

AU - Saito, Siro

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N2 - Purpose: This multicenter study was conducted to evaluate the current variability of treatment planning of seed implantation in Japanese centers and the feasibility of two virtual trials. Methods and Materials: Two types of contour data were sent to 12 radiation oncologists with a request letter that asked them to make treatment plans on the data in the same manner as in their own practice. Five of the 12 radiation oncologists were asked to participate in the two virtual trials in which the D90 (dose to the hottest 90% of prostate volume) was 1) required to be set at just 180 Gy and 2) increased as much as possible without violating other limitations. Results: A relatively high dose with a small deviation was irradiated to the prostate in Japanese centers (mean D90 = 188 Gy; SD = 10 Gy). In the virtual trials, all five physicians could achieve 180 Gy for the D90 with a very small deviation, although the urethral dose showed relatively large deviations. Dose escalation without increase of urethral dose or V150 was difficult, although the rectum could be spared by most of the physicians. Conclusion: Our study showed a relatively high dose with a small deviation was prescribed to the prostate in Japanese centers. Consolidated protocols such as D90 = 180 Gy could be available for future trials. Meanwhile, our study suggested that some cautions might be needed for urethral dose and the V150, even when a relatively low D90 was requested.

AB - Purpose: This multicenter study was conducted to evaluate the current variability of treatment planning of seed implantation in Japanese centers and the feasibility of two virtual trials. Methods and Materials: Two types of contour data were sent to 12 radiation oncologists with a request letter that asked them to make treatment plans on the data in the same manner as in their own practice. Five of the 12 radiation oncologists were asked to participate in the two virtual trials in which the D90 (dose to the hottest 90% of prostate volume) was 1) required to be set at just 180 Gy and 2) increased as much as possible without violating other limitations. Results: A relatively high dose with a small deviation was irradiated to the prostate in Japanese centers (mean D90 = 188 Gy; SD = 10 Gy). In the virtual trials, all five physicians could achieve 180 Gy for the D90 with a very small deviation, although the urethral dose showed relatively large deviations. Dose escalation without increase of urethral dose or V150 was difficult, although the rectum could be spared by most of the physicians. Conclusion: Our study showed a relatively high dose with a small deviation was prescribed to the prostate in Japanese centers. Consolidated protocols such as D90 = 180 Gy could be available for future trials. Meanwhile, our study suggested that some cautions might be needed for urethral dose and the V150, even when a relatively low D90 was requested.

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