PD13-01 NOVEL SIMULATING MODEL OF THE SURVEILLANCE DURATION AFTER LOW DOSE RATE BRACHYTHERAPY FOR PROSTATE CANCER PATIENTS: AN INDIVIDUALIZED RISK-BASED METHOD APPLYING WEIBULL DISTRIBUTIONS

You have accessJournal of UrologyProstate Cancer: Epidemiology & Natural History I (PD13)1 Sep 2021PD13-01 NOVEL SIMULATING MODEL OF THE SURVEILLANCE DURATION AFTER LOW DOSE RATE BRACHYTHERAPY FOR PROSTATE CANCER PATIENTS: AN INDIVIDUALIZED RISK-BASED METHOD APPLYING WEIBULL DISTRIBUTIONS Masanori Hasegawa, Shiro Saito, Atsunori Yorozu, Tetsuo Momma, Yasuto Yagi, Toru Nishiyama, Yu Ozawa, Keisuke Shigeta, Koichiro Yamada, Soichiro Yuzuriha, Sunao Shoji, and Akira Miyajima Masanori HasegawaMasanori Hasegawa More articles by this author , Shiro SaitoShiro Saito More articles by this author , Atsunori YorozuAtsunori Yorozu More articles by this author , Tetsuo MommaTetsuo Momma More articles by this author , Yasuto YagiYasuto Yagi More articles by this author , Toru NishiyamaToru Nishiyama More articles by this author , Yu OzawaYu Ozawa More articles by this author , Keisuke ShigetaKeisuke Shigeta More articles by this author , Koichiro YamadaKoichiro Yamada More articles by this author , Soichiro YuzurihaSoichiro Yuzuriha More articles by this author , Sunao ShojiSunao Shoji More articles by this author , and Akira MiyajimaAkira Miyajima More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001989.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: There is currently insufficient evidence on the appropriate surveillance duration after low-dose-rate brachytherapy (LDR) with iodine-125 for localized prostate cancer (PCa) patients. We aimed to establish more meaningful and individualized surveillance durations to detect subsequent biochemical recurrence (BCR) defined by PSA recurrence after LDR in PCa patients. METHODS: We identified 2453 PCa patients who underwent LDR. The hazard rate (HR) transition of BCR and non-PCa death was estimated by applying parametric models for time to failure with Weibull distributions. The overtime risk transition of BCR was classified according to risk, and the risk of non-PCa death was stratified according to chronological age. RESULTS: At a median follow-up of 6.2 years, a total of 148 (6.0%) patients developed subsequent BCR, and 146 (6.0%) patients died due to other causes. The HR of BCR was the highest with high-risk, followed by intermediate and low-risk groups (e.g., high-risk patients had 7.7 times higher HR of developing BCR than low-risk patients). The risk for BCR in all groups increased over time, and the slope gradually decreased. However, the HR of non-PCa death was higher among the elderly patients (e.g., ≥76 y/o showed 8.1 times higher HR of non-PCa death than those of ≤60 y/o). This constantly increased in all age groups. Based on the Weibull model estimate, we calculated the age- and risk-specific time points when the non-PCa death risk exceeded that of BCR. Among patients ≤60 y/o, the HR of non-PCa death exceeded BCR at 7.1 years after LDR for the low group. However, the HR of BCR remained greater for more than 20 years for the intermediate and high risk groups. In patients 61-75 y/o, the HR of non-PCa death exceeded the HR of developing BCR at 1.2, 4.8, and over 20 years, and with ≥76 y/o at 0.4, 1.5, and 6.6 years for the low-, intermediate-, and high-risk groups, respectively. CONCLUSIONS: Our study demonstrated that the risk of non-PCa death overcomes the risk of BCR as the survival year increases after LDR. However, especially for younger and/or higher-risk patients, a follow-up duration of 20 years or more may be recommended for detecting subsequent BCR after LDR. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e209-e209 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Masanori Hasegawa More articles by this author Shiro Saito More articles by this author Atsunori Yorozu More articles by this author Tetsuo Momma More articles by this author Yasuto Yagi More articles by this author Toru Nishiyama More articles by this author Yu Ozawa More articles by this author Keisuke Shigeta More articles by this author Koichiro Yamada More articles by this author Soichiro Yuzuriha More articles by this author Sunao Shoji More articles by this author Akira Miyajima More articles by this author Expand All Advertisement PDF downloadLoading ...