Over a century ago, low-dose-rate (LDR) brachytherapy was introduced to treat prostate cancer (PCa). Since then, it has been widely applied worldwide, including in East Asia. LDR brachytherapy has been performed in 88 institutes in Japan. Beneficial clinical outcomes of LDR brachytherapy for intermediate-to-high-risk PCa have been demonstrated in large clinical trials. These clinical outcomes were achieved through advances in methods, such as urological precise needle puncture and seed placement, and the quantitative decision making regarding radiological parameters by radiation oncologists. The combined use of LDR brachytherapy with other therapeutic modalities, such as external beam radiation and androgen deprivation therapy, for the clinical risk classification of PCa has led to better anticancer treatment efficacy. In this study, we summarized basic LDR brachytherapy findings that should remain unchanged and be passed down in urology departments. We also discussed the applications of LDR brachytherapy for PCa in various clinical settings, including focal and salvage therapies. In addition, we highlighted technologies associated with brachytherapy that are under development.

Radiation therapy, including external-beam radiation therapy (EBRT) and brachytherapy, is curative for localized prostate cancer. Hydrogel spacer (HS) placement between the rectum and prostate is popular for reducing radiation-related complications. Criteria to identify patients who benefit from HS placement would be clinically valuable. In a retrospective analysis of 430 patients with localized prostate cancer treated between November 2010 and March 2023 with ≥2 years of follow-up, we evaluated the incidence of rectal hemorrhage and its association with the median distance at the midpoint between the prostate and the rectum (mDPR) on pretreatment MRI. Rectal hemorrhage occurred in 6% of HS cases and 18% of non-HS cases (p < 0.001). Among 268 patients who received EBRT (±brachytherapy), the incidence was 9% with HS and 30% without HS (p < 0.001). In non-HS cases, the rate in patients with mDPR ≤ 1.62 mm was higher than in those with mDPR > 1.62 mm (24% vs. 12%, respectively; p = 0.04). In patients with EBRT and mDPR ≤ 1.62 mm, HS significantly reduced hemorrhage (9% vs. 39%, respectively; p < 0.001). Multivariate analysis identified mDPR and HS as independent predictors of rectal hemorrhage (both p = 0.02). Thus, HS placement may be safely omitted in non-EBRT cases with mDPR ≥ 1.62 mm.

Fluoroquinolones (FQs) have been traditionally used for prophylaxis against bacterial infection. However, the rapid emergence of FQ-resistant Escherichia coli due to overuse and misuse have resulted in an increase in post-biopsy infections. We requested 723 patients undergoing transrectal or transrectal plus transperineal targeted prostate biopsy to provide preprocedure rectal swabs. The rectal swabs were plated onto deoxycholate hydrogen sulfate lactose agar culture and FQ resistance tests were conducted using the disc diffusion method following the guidelines of the Clinical and Laboratory Standards Institute. All patients undergoing biopsy were given a 1.0 g intravenous injection of cefmetazole (CMZ) 30 min before and 12 h after biopsy. Patients with FQ-resistant organisms received an additional 1.0 g intravenous injection of CMZ every 12 h for an additional 1.5 days, while those without FQ-resistant organisms received levofloxacin 500 mg for 4 days. We evaluated infectious symptoms during the 30 days after the biopsy. We also evaluated the incidence of acute prostatitis within 7 days after the biopsy and isolation rates of FQ-resistant strains. A total of 289 patients (40%) had FQ-resistant isolates on rectal swabs. The overall infectious complication rate was 0.69%. Two patients with FQ-resistant isolates and three patients without them experienced infectious episodes. One patient with FQ-resistant isolates and two patients without them suffered acute prostatitis. The difference in the rates of infectious complication and acute prostatitis rates between FQ-resistant and FQ-susceptible carriers were not significant (p = 1.0 and 1.0, respectively). Post-biopsy sepsis was identified in one patient (0.14%) who had FQ-resistant Escherichia coli. Targeted antimicrobial prophylaxis with cefmetazole based on presence of FQ-resistant isolates on rectal swabs may prevent post-prostate biopsy infectious complications, especially in geographic lesions with a high incidence of FQ-resistant strains in rectal flora.

Over a century ago, low-dose-rate (LDR) brachytherapy was introduced to treat prostate cancer (PCa). Since then, it has been widely applied worldwide, including in East Asia. LDR brachythera-py has been performed in 88 institutes in Japan. Beneficial clinical outcomes of LDR brachytherapy for intermediate-to-high-risk PCa have been demonstrated in large clinical trials. These clinical outcomes were achieved through advances in methods, such as urological precise needle puncture and seed placement, and the quantitative decision-making regarding radiological parameters by radiation oncologists. Combined use of LDR brachytherapy with other therapeutical modalities, such as external beam radiation and androgen deprivation therapy, for clinical risk classification of PCa has led to better anticancer treatment efficacy. In this study, we summarized basic LDR brachytherapy findings that should remain unchanged and be passed down in urology depart-ments. We also discussed the applications of LDR brachytherapy for PCa in various clinical settings, including focal and salvage therapies. In addition, we highlighted technologies associated with brachytherapy that are under development.