Correlation between urinary dose and delayed radiation cystitis after 78 Gy intensity-modulated radiotherapy for high-risk prostate cancer: A 10-year follow-up study of genitourinary toxicity in clinical practice

Haruo Inokuchi, Takashi Mizowaki, Yoshiki Norihisa, Kenji Takayama, Itaru Ikeda, Kiyonao Nakamura, Masahiro Hiraoka

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    2 Scopus citations

    Abstract

    Purpose To investigate the factors associated with the risk of long-term genitourinary (GU) toxicity among high-risk prostate cancer (PC) patients treated with high-dose intensity-modulated radiotherapy (IMRT). Methods and materials Between 2000 and 2011, PC patients treated with 78 Gy in 39 fractions delivered by IMRT combined with neo-adjuvant hormonal therapy were selected from among our database. GU toxicities and clinical factors, as well as separate anatomical urinary structures, were evaluated in terms of their associations. Results A total of 309 patients was included in this study. The median follow-up was 104 months (range: 24–143 months). The most frequently observed late grade ≥2 GU toxicity was hematuria (11.2%: 10-year actuarial risk) with radiation cystitis observed in the majority of patients. In univariate analysis, late grade ≥2 hematuria was associated with the exposure to doses >75 Gy (V75) of the bladder neck and V70 of the bladder wall, as well as with T stage. V75 of the bladder neck remained significant in multivariate analysis (p = 0.049). Conclusions At the 10-year follow up of high-dose IMRT, a major concern was proved to be delayed cystitis related to the higher volume of bladder neck dose exposed excess over 75 Gy.

    Original languageEnglish (US)
    Pages (from-to)31-36
    Number of pages6
    JournalClinical and Translational Radiation Oncology
    Volume6
    DOIs
    StatePublished - Oct 1 2017

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    Keywords

    • GU toxicity
    • Intensity-modulated radiation therapy
    • Long term follow-up
    • Prostate cancer
    • Urinary dose

    ASJC Scopus subject areas

    • Oncology
    • Radiology Nuclear Medicine and imaging

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