Urinary and Rectal Toxicity Profiles After Permanent Iodine-125 Implant Brachytherapy in Japanese Men: Nationwide J-POPS Multi-institutional Prospective Cohort Study.
OBJECTIVE
To assess, in a nationwide multi-institutional cohort study begun in 2005 and in which 6927 subjects were enrolled by 2010, the urinary and rectal toxicity profiles of subjects who enrolled during the first 2 years, and evaluate the toxicity profiles for permanent seed implantation (PI) and a combination therapy with PI and external beam radiation therapy (EBRT).


METHODS
Baseline data for 2339 subjects out of 2354 patients were available for the analyses. Toxicities were evaluated using the National Cancer Institute's Common Terminology Criteria for Adverse Events, and the International Prostate Symptom Scores were recorded prospectively until 36 months after radiation therapy.


RESULTS
Grade 2+ acute urinary toxicities developed in 7.36% (172 of 2337) and grade 2+ acute rectal toxicities developed in 1.03% (24 of 2336) of the patients. Grade 2+ late urinary and rectal toxicities developed in 5.75% (133 of 2312) and 1.86% (43 of 2312) of the patients, respectively. A higher incidence of grade 2+ acute urinary toxicity occurred in the PI group than in the EBRT group (8.49% vs 3.66%; P<.01). Acute rectal toxicity outcomes were similar between the treatment groups. The 3-year cumulative incidence rates for grade 2+ late urinary toxicities were 6.04% versus 4.82% for the PI and the EBRT groups, respectively, with no significant differences between the treatment groups. The 3-year cumulative incidence rates for grade 2+ late rectal toxicities were 0.90% versus 5.01% (P<.01) for the PI and the EBRT groups, respectively. The mean of the postimplant International Prostate Symptom Score peaked at 3 months, but it decreased to a range that was within 2 points of the baseline score, which was observed in 1625 subjects (69.47%) at the 1-year follow-up assessment.


CONCLUSIONS
The acute urinary toxicities observed were acceptable given the frequency and retention, and the late rectal toxicities were more favorable than those of other studies.
Keio University School of Medicine, Tokyo, Japan. Electronic address: ohashi@rad.med.keio.ac.jp.
Toshio
T
Ohashi
National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
Atsunori
A
Yorozu
National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
Shiro
S
Saito
Nara Medical University School of Medicine, Nara, Japan.
Nobumichi
N
Tanaka
Okayama University School of Medicine, Okayama, Japan.
Norihisa
N
Katayama
Translational Research Informatics Center, Hyogo, Japan.
Shinsuke
S
Kojima
Translational Research Informatics Center, Hyogo, Japan.
Shinichiro
S
Maruo
Translational Research Informatics Center, Hyogo, Japan.
Takashi
T
Kikuchi
Kyoundo Hospital, Tokyo, Japan.
Takushi
T
Dokiya
Translational Research Informatics Center, Hyogo, Japan.
Masanori
M
Fukushima
Institutes of Preventive Medicine, Kurosawa Hospital, Gunma, Japan.
Hidetoshi
H
Yamanaka
D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use; D007564:Japan; D008297:Male; D008875:Middle Aged; D058958:Organs at Risk / Q000528:radiation effects*; D011446:Prospective Studies; D011467:Prostate / Q000528:radiation effects*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000473:pathology*; D011879:Radiotherapy Dosage; D012007:Rectum / Q000528:radiation effects*; D014521:Urethra / Q000528:radiation effects*
D007457:Iodine Radioisotopes; D017430:Prostate-Specific Antigen