UNASSIGNED: To evaluate international prostate symptom score and urinary quality of life in patients with prostate cancer who underwent low-dose-rate brachytherapy, and to identify lower urinary tract symptoms that must be improved to enhance post-operative urinary quality of life and factors associated with lower urinary tract symptoms.
UNASSIGNED: This study included 193 patients who underwent low-dose-rate brachytherapy alone (145 Gy). Importance-performance analysis was conducted to identify lower urinary tract symptoms that should be prioritized to improve urinary quality of life. Association between lower urinary tract symptom scores and each factor was investigated. Receiver operating characteristic curve analysis was used to evaluate dosimetric parameters related to lower urinary tract symptom score to predict an average score of ≥ 3. Cut-off values were determined.
UNASSIGNED: One to nine months post-implantation was a period of significantly increased urinary quality of life scores compared with baseline (p < 0.05 each). The importance-performance analysis conducted for 1-9 months revealed that frequency, nocturia, and weak stream required improvement. Multivariate analysis showed that each lower urinary tract symptom score presented a significant association with its baseline value (p < 0.001 each, positive correlation). Frequency, incomplete emptying, urgency, and straining scores were significantly associated with prostate volume, whereas weak stream and intermittency scores were associated with dose covering 90% of the prostate and dose covering 90% of the urethra, respectively (p < 0.05 each, positive correlations). Cut-off values for these doses were 167.01 Gy and 136.84 Gy, respectively.
UNASSIGNED: This study highlights the importance of prioritizing specific lower urinary tract symptoms for improvement in post-operative urinary quality of life, and identifies the associated factors that can help in personalized treatment planning and goal-setting for better patient satisfaction.

We aimed to retrospectively review outcomes in patients with high-risk prostate cancer and a Gleason score ≤ 6 following modern radiotherapy. We analyzed the outcomes of 1374 patients who had undergone modern radiotherapy, comprising a high-risk low grade [HRLG] group (Gleason score ≤ 6; n = 94) and a high-risk high grade [HRHG] group (Gleason score ≥ 7, n = 1125). We included 955 patients who received brachytherapy with or without external beam radio-therapy (EBRT) and 264 who received modern EBRT (intensity-modulated radiotherapy [IMRT] or stereotactic body radiotherapy [SBRT]). At a median follow-up of 60 (2-177) months, actuarial 5-year biochemical failure-free survival rates were 97.8 and 91.8% (p = 0.017), respectively. The frequency of clinical failure in the HRLG group was less than that in the HRHG group (0% vs 5.4%, p = 0.012). The HRLG group had a better 5-year distant metastasis-free survival than the HRHG group (100% vs 96.0%, p = 0.035). As the HRLG group exhibited no clinical failure and better outcomes than the HRHG group, the HRLG group might potentially be classified as a lower-risk group.

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.

OBJECTIVE: Intermediate-risk prostate cancer (PCa) is a highly heterogeneous disease. Although low-dose-rate brachytherapy (LDR-BT) is mainly used for low- to intermediate-risk PCa, limited reports have evaluated the detailed differences in outcomes, including differences between patients with ISUP grade group (GG) 2 and GG3 intermediate-risk PCa. This study aimed to investigate the differences in outcomes between intermediate-risk Japanese patients with GG2 and GG3 PCa who underwent LDR-BT.
METHODS: This single-center retrospective study included 342 consecutive patients with intermediate-risk PCa; 232 patients with GG2 and 110 with GG3 were treated with LDR-BT at Tokushima University Hospital between July 2004 and December 2019.
RESULTS: No significant difference in 5-year biochemical progression-free survival and cancer-specific survival was observed between patients with GG2 and those with GG3 (p=0.649 and p=0.633, respectively). Multivariate analysis showed that radiation doses up to 90% of the prostate volume (D90) and the percentage of positive cores were predictors of recurrence in all patients with intermediate-risk PCa. Group analyses showed that D90 was a predictor for recurrence in patients with GG2. In contrast, a high percentage of positive cores was a significant risk factor for recurrence in patients with GG3.
CONCLUSIONS: Positive core ratios observed on prostate biopsy correlated with higher recurrence rates after LDR-BT. This indicates that the proportion of positive cores in the biopsy may be an important factor in predicting the likelihood of recurrence, especially for patients with GG3 PCa.

Around 40 years have passed since a modern low-dose-rate (LDR) brachytherapy for prostate cancer was introduced. LDR brachytherapy has become one of the definitive treatment options besides radical prostatectomy (RP) and external beam radiation therapy (EBRT). LDR brachytherapy has several advantages over EBRT such as a higher prescribed dose to the prostate gland while avoiding unnecessary irradiation of organs at risk, a precipitous dose gradient, a brief treatment time, and a short hospital stay. Previous reports revealed that the long-term oncologic outcomes of LDR brachytherapy are superior to those of EBRT. The oncologic outcomes of low- to intermediate-risk patients are equivalent to those of RP using the recurrence definition of surgery of prostate specific antigen (PSA) >0.2 ng/mL, while the oncologic outcomes of LDR brachytherapy as tri-modality (combined EBRT and androgen deprivation therapy) for high-risk patients is superior to that of RP using the recurrence definition of surgery. In respect of toxicity, urinary disorders such as urgency and frequency are often observed after the acute phase of treatment, but these events usually resolve, while the quality of life of urinary continence is well preserved for a long time. Erectile function decreases yearly, but is relatively preserved compared to RP. In conclusion, the most noteworthy strength of LDR brachytherapy for low- to intermediate-risk patients is the \"brief treatment time\" that provides long recurrence-free survival, while that for high-risk patients who received LDR brachytherapy (tri-modality) is \"excellent disease control.\"

In conducting dosimetric assays of seed sources containing iodine-125 (125I), several major guidelines require the medical physicist to verify the source strength before patient treatment. Japanese guidelines do not mandate dosimetric assays at medical facilities, but since 2017, three incidents have occurred in Japan wherein seeds with incorrect strengths were delivered to medical facilities. Therefore, this study aimed to survey the current situation and any barriers to conducting the dosimetric assay of iodine-125 seeds at medical facilities in Japan. We conducted a questionnaire-based survey from December 2020 to April 2021, to examine whether seed assay and verification of the number of seeds delivered were being performed. We found that only 9 facilities (16%) performed seed assay and 28 (52%) verified the number of seeds. None of the facilities used an assay method that ensured traceability. The reasons for not performing an assay were divided into two categories: lack of resources and legal issues. Lack of resources included lack of instruments, lack of knowledge of assay methods, shorthand, or all of the above, whereas legal issues included the inability to resterilize iodine-125 seeds distributed in Japan and/or purchase seeds dedicated to the assay. Dosimetric assays, including simple methods, are effective in detecting calibration date errors and non-radioactive seeds. The study findings suggest that familiarization of medical personnel with these assay methods and investigation of the associated costs of labor and equipment should be recommended, as these measures will lead to medical reimbursement for quality assurance.

BACKGROUND: To compare chronological changes in lower urinary tract symptoms (LUTS) after low-dose-rate prostate extended-release therapy (LDR-BT) using the overactive bladder symptom score (OABSS) in patients aged ≥ 75 years (elderly group) versus those aged < 75 years (control group).
METHODS: Patients with prostate cancer who underwent LDR-BT at Gifu University Hospital were included in this study. The International Prostate Symptom Score (IPSS), OABSS, and quality of life-based on urinary symptoms (IPSS-QOL) were evaluated before and after LDR-BT. We compared chronological changes in IPSS, OABSS, and IPSS-QOL in the elderly group with those in the control group and assessed the association between the resolution of OABSS and clinicopathological covariates.
RESULTS: A total of 484 patients were enrolled in this study. In the elderly group, the total IPSS, OABSS, and frequency scores increased at 1 month postoperatively, whereas the control group showed an increase at 3 months postoperatively. Multivariate analysis identified changes from baseline to the maximum OABSS and pre-treatment OABSS as significant predictors of delayed resolution of OABSS after LDR-BT.
CONCLUSIONS: Changes in pre-treatment OABSS and pre- and post-LDR-BT OABSS values were independent predictors of delayed resolution of OABSS; however, no correlation was found with age.

BACKGROUND: To explore correlations between the clinical attributes of secondary bladder cancer and brachytherapy, we retrospectively reviewed our institutional database on patients with localized prostate cancer who underwent low-dose-rate brachytherapy (LDR-BT) or high-dose-rate brachytherapy (HDR-BT) with or without external beam radiation therapy (EBRT) or radical prostatectomy (RP).
METHODS: From October 2003 to December 2014, 2551 patients with localized prostate cancer were treated at our institution. Of these, data on 2163 were available (LDR-BT alone: n = 953; LDR-TB with EBRT: n = 181; HDR-BT with EBRT: n = 283; RP without EBRT: n = 746). The times of secondary bladder cancer development subsequent to radical treatment, and their clinical characteristics, were studied.
RESULTS: Age-adjusted Cox\'s regression analyses indicated that brachytherapy did not significantly impact the incidence of secondary bladder cancer. However, the pathological characteristics of such cancer differed between patients treated via brachytherapy and RP without EBRT; invasive bladder cancer was more common in such patients.
CONCLUSIONS: The risk for secondary bladder cancer was not significantly increased after brachytherapy compared to non-irradiation therapy. However, brachytherapy patients exhibited a higher incidence of invasive bladder cancer. Therefore, meticulous follow-up is crucial for early detection and treatment of bladder cancer in such patients.

OBJECTIVE: We retrospectively investigated the effect of a biologically effective dose (BED) of Low-dose rate brachytherapy (LDR-BT) and its possible interaction with androgen deprivation therapy (ADT) during LDR-BT treatment for intermediate-risk prostate cancer (PCa).
METHODS: A total of 693 patients with localized, intermediate-risk PCa, who underwent LDR-BT with or without supplemental external beam radiotherapy, were included in this study. We stratified patients into two groups according to BED (<180 Gy2, lower BED group; ≥180 Gy2, higher BED group) and evaluated the effect of ADT duration on the oncological outcomes of each group.
RESULTS: In total, 431 patients received BED ≥180 Gy2. Significant differences in biochemical recurrence-free survival (BCRFS) and clinical progression-free survival (CPFS) were observed among the non-ADT, ADT ≤3 months, and ADT >3 months subgroups of the lower BED group (p=0.005 and 0.049, respectively). However, no significant differences in BCRFS or CPFS were detected in the higher BED group (p=0.63 and 0.76, respectively). Multivariate analysis of BCR and CP in the lower BED group revealed a significant decreasing trend in the BCRFS (p for trend=0.001) and CPFS rates (p for trend=0.015) as ADT duration increased, which was associated with favorable outcomes. However, no significant trend was observed in the BCRFS or CPFS rate in the higher BED group.
CONCLUSIONS: An adequate local radiation dose provides favorable oncological outcomes and could potentially reduce the need for long-term ADT.

BACKGROUND: This study aims to compare the clinical outcomes after performing radical prostatectomy (RP) or low-dose-rate brachytherapy (LDR) for patients with intermediate-risk prostate cancer (IRPC).
METHODS: We performed a retrospective analysis on 361 IRPC patients who underwent treatment in Peking Union Medical College Hospital from January 2014 to August 2021, of which 160 underwent RP and 201 underwent Iodine-125 LDR. Patients were followed in clinic monthly during the first three months and at three-month intervals thereafter. Univariate and multivariate regression analyses were conducted to predict biochemical relapse-free survival (bRFS), clinical relapse-free survival (cRFS), cancer-specific survival (CSS), and overall survival (OS). Biochemical recurrence was defined using the Phoenix definition for LDR and the surgical definition for RP. The log-rank test was applied to compare bRFS between the two modalities, and Cox regression analysis was performed to identify factors associated with bRFS.
RESULTS: Median follow-up was 54 months for RP and 69 months for LDR. According to log-rank test, the differences of 5-year bRFS (70.2% vs 83.2%, P = 0.003) and 8-year bRFS (63.1% vs 68.9%, P < 0.001) between RP and LDR groups were statistically significant. Our results also indicated that there was no significant difference in terms of cRFS, CSS, or OS between the two groups. With multivariate analysis of the entire cohort, prostate volume ≤ 30 ml (P < 0.001), positive margin (P < 0.001), and percentage positive biopsy cores > 50% (P < 0.001) were independent factors suggestive of worse bRFS.
CONCLUSIONS: LDR is a reasonable treatment option for IRPC patients, yielding improved bRFS and equivalent rates of cRFS, CSS and OS when compared with RP.