International Journal of Clinical Oncology

, Volume 20, Issue 2, pp 375–385

Nationwide Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS)


    • Department of UrologyNational Hospital Organization Tokyo Medical Center
  • Kazuto Ito
    • Department of UrologyGunma University
  • Atsunori Yorozu
    • Department of Radiation OncologyNational Hospital Organization Tokyo Medical Center
  • Manabu Aoki
    • Department of Radiation OncologyJikei University School of Medicine
  • Hirofumi Koga
    • Department of UrologyHara Sanshin Hospital
  • Takefumi Satoh
    • Department of UrologyKitasato University School of Medicine
  • Toshio Ohashi
    • Department of Radiation OncologyKeio University School of Medicine
  • Naoyuki Shigematsu
    • Department of Radiation OncologyKeio University School of Medicine
  • Shinichiro Maruo
    • Translational Research Informatics Center
  • Takashi Kikuchi
    • Translational Research Informatics Center
  • Shinsuke Kojima
    • Translational Research Informatics Center
  • Takushi Dokiya
    • Department of Radiation OncologySaitama Medical College
  • Masanori Fukushima
    • Translational Research Informatics Center
  • Hidetoshi Yamanaka
    • Institutes of Preventive MedicineKurosawa Hospital
Original Article

DOI: 10.1007/s10147-014-0704-4

Cite this article as:
Saito, S., Ito, K., Yorozu, A. et al. Int J Clin Oncol (2015) 20: 375. doi:10.1007/s10147-014-0704-4



To evaluate the safety and efficacy of brachytherapy with permanent iodine-125 seed implantation (PI) for prostate cancer. The nationwide Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS) has continued since July 2005. This manuscript presents the rationale, J-POPS study design, and the characteristics of initial participants enrolled in this study from July 2005 to June 2007.


All participants were treated with PI in accordance with the American Brachytherapy Society recommendations. The primary outcome measure was biochemical progression-free survival. Progression-free survival, overall survival, cause-specific survival, longitudinal changes in health-related quality of life, disease-specific quality of life, the International Prostate Symptom Score, and the incidence of adverse events were also investigated as secondary outcome measurements.


Overall, 6,927 patients were enrolled by the end of 2010, that is approximately 40 % of all cases treated around the country. During the first 2 years, 2,354 participants were enrolled and 2,339 were actually treated with PI. The age range of participants was 45 to 89 years (median 69 years) and their risk classifications were 1,037 (44.3 %) at low risk, 1,126 (48.1 %) at intermediate risk, and 134 (5.7 %) at high risk, in addition to 16 participants whose classification was unknown. Of all patients, 76.6 % were treated with PI without external beam radiation therapy and 49.3 % received neoadjuvant hormone therapy.


The J-POPS, a nationwide prospective cohort study that enrolled approximately 40 % of all PI cases in Japan, will provide highly reliable evidence, including outcomes and quality of life, after long-term follow-up.


BrachytherapyIodine-125Multi-institutional prospective cohort studyProstate cancer

Copyright information

© Japan Society of Clinical Oncology 2014