Predictive factors for urinary toxicity after iodine-125 prostate brachytherapy with or without supplemental external beam radiotherapy

Takahisa Eriguchi; Atsunori Yorozu; Nobuko Kuroiwa; Yasuto Yagi; Toru Nishiyama; Shiro Saito; Kazuhito Toya; Takashi Hanada; Yutaka Shiraishi; Toshio Ohashi; Naoyuki Shigematsu

doi:10.1016/j.brachy.2015.12.011

Predictive factors for urinary toxicity after iodine-125 prostate brachytherapy with or without supplemental external beam radiotherapy

Brachytherapy. 2016 May-Jun;15(3):288-295. doi: 10.1016/j.brachy.2015.12.011. Epub 2016 Feb 28.

Authors

Affiliations

¹ Department of Radiology, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan; Department of Radiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan. Electronic address: [email protected].
² Department of Radiology, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan.
³ Department of Urology, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan.
⁴ Department of Urology, National Hospital Organization Tokyo Medical Center, Meguro-ku, Tokyo, Japan; Department of Radiology, International University of Health and Welfare Mita Hospital, Minato-ku, Tokyo, Japan.
⁵ Department of Radiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.

PMID: 26924022
DOI: 10.1016/j.brachy.2015.12.011

Abstract

Purpose: We examined the factors associated with urinary toxicities because of brachytherapy with iodine-125 with or without supplemental external beam radiotherapy (EBRT) for prostate cancer.

Methods and materials: We investigated 1313 patients with localized prostate cancer treated with iodine-125 brachytherapy with or without supplemental EBRT between 2003 and 2009. The International Prostate Symptom Score (IPSS) and Common Terminology Criteria for Adverse Events data were prospectively determined. Patients, treatment, and implant factors were investigated for their association with urinary toxicity or symptoms.

Results: IPSS resolution was not associated with biologically effective dose (BED). Baseline IPSS, total needles, and the minimal dose received by 30% of the urethra had the greatest effect according to multivariate analysis (MVA). Urinary symptom flare was associated with baseline IPSS, age, BED, and EBRT on MVA. Urinary symptom flare and urinary Grade 2 or higher (G2+) toxicity occurred in 51%, 58%, and 67% (p = 0.025) and 16%, 22%, and 20% (p = 0.497) of the <180, 180-220, and >220 Gy BED groups, respectively. Urinary G2+ toxicity was associated with baseline IPSS, neoadjuvant androgen deprivation therapy (NADT), and seed density on MVA. When we divided patients into four groups according to prostate volume (<30 cc or ≥30 cc) and NADT use, urinary G2+ toxicity was most commonly observed in those patients with larger prostates who received NADT, and least in the patients with smaller prostates and no NADT.

Conclusions: NADT was associated with urinary G2+ toxicity. Higher dose and supplemental EBRT did not appear to increase moderate to severe urinary toxicities or time to IPSS resolution; however, it influenced urinary symptom flare.

Keywords: (125)I; Brachytherapy; Higher biological effective dose; Neoadjuvant androgen deprivation therapy; Prostate cancer; Supplemental external beam radiotherapy; Urinary toxicity.

MeSH terms

Adult
Age Factors
Aged
Aged, 80 and over
Androgen Antagonists / adverse effects
Brachytherapy / adverse effects*
Humans
Iodine
Iodine Radioisotopes / adverse effects
Lower Urinary Tract Symptoms / etiology*
Male
Middle Aged
Neoadjuvant Therapy / adverse effects
Organ Size
Prostate / pathology*
Prostate-Specific Antigen / blood
Prostatic Neoplasms / complications
Prostatic Neoplasms / drug therapy
Prostatic Neoplasms / pathology
Prostatic Neoplasms / radiotherapy*
Radiotherapy Dosage
Risk Factors
Severity of Illness Index
Symptom Flare Up
Urethra / radiation effects*

Substances

Androgen Antagonists
Iodine Radioisotopes
Iodine
Prostate-Specific Antigen