Publications by authors named "Isao Asakawa"

Utility values of responders and nonresponders are essential inputs in cost-effectiveness studies of radiation therapy for painful bone metastases but, to our knowledge, they have not been reported separately. We sought to determine the utility values of responders and nonresponders using data from a prospective observational study on bone metastases. The original prospective observational study was conducted at 26 centers in Japan.

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Objectives: The objectives of the study are to evaluate the oncological and functional outcomes of three bladder preservation regimens: radiotherapy alone (RT-alone group), concurrent chemoradiotherapy (CRT) using gemcitabine plus platinum (GP-RT group), and low-dose gemcitabine (LD-Gem-RT group) for muscle-invasive bladder cancer.

Methods: The three oncological outcomes, bladder-intact distant metastasis-free survival (BI-DMFS), cancer-specific survival, and overall survival (OS), were compared among RT alone ( = 10), GP-RT ( = 16), and LD-Gem-RT ( = 11) groups. Treatment-related adverse events were evaluated against the Common Terminology Criteria for Adverse Events (version 5.

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Article Synopsis
  • This study aimed to evaluate the real-world impact of radiotherapy for bone metastases on patients' quality of life (QOL) using data from 26 centers in Japan.
  • Out of 333 patients receiving treatment, 232 were included, and their QOL was assessed at enrollment and followed up at two and six months using standardized questionnaires.
  • Results showed significant improvements in several QOL areas, especially pain and insomnia, indicating that radiotherapy can positively affect some aspects of patient well-being in practice.
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Background/aim: Radiotherapy is one of the most frequently used options for prostate cancer (PCa). However, adverse effects related to irradiation of surrounding normal organs are significant clinical concerns. Specifically, genitourinary toxicity can dramatically reduce the quality of life.

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Article Synopsis
  • The study investigated how prostate-specific antigen (PSA) levels and PSA bounce relate to cancer control after treatments like low-dose-rate brachytherapy (LDR-BT) and external beam radiotherapy (EBRT), with or without hormone therapy, while considering testosterone levels.
  • Researchers examined 944 prostate cancer patients to determine the impact of PSA levels (specifically 0.1, 0.2, or 0.5 ng/mL) and the occurrence of PSA bounce over several years post-treatment using statistical models.
  • Findings indicated that patients with normal testosterone who maintained lower PSA levels after treatment had significantly better outcomes in avoiding clinical failures, as did those who experienced a bounce in PSA levels during the early years.
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Background: Urinary dysfunction is an adverse event of low-dose-rate brachytherapy (LDR-BT) in patients with prostate cancer. We aimed to examine the time to α-1 adrenergic antagonist withdrawal after LDR-BT initiation.

Methods: We retrospectively evaluated 1663 patients who underwent LDR-BT at our hospital during 2004-2022.

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Article Synopsis
  • This study assessed the characteristics, treatments, and outcomes of patients receiving radiotherapy for bone metastases across 26 hospitals in Japan from December 2020 to March 2021.* -
  • Out of 232 patients enrolled, findings showed that 52% experienced pain relief within two months, with a notable overall survival rate of 70.2% at six months.* -
  • Key observations included that 59% of patients had spinal metastases, the biologically effective dose (BED) of radiation varied widely, and the incidence of severe adverse events was low, with no significant relationship between BED and pain relief.*
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Background: It is unclear whether a hydrogel spacer can improve quality of life (QOL) in patients undergoing low-dose-rate brachytherapy (LDR-BT) alone or in combination with intensity-modulated radiotherapy (IMRT).

Methods: We enrolled patients with prostate cancer who underwent LDR-BT alone with (n = 186) or without (n = 348) a hydrogel spacer, or underwent LDR-BT in combination with IMRT with (n = 70) or without (n = 217) a hydrogel spacer. QOL was evaluated using Expanded Prostate Cancer Index Composite (EPIC) questionnaires at baseline and 1, 3, 6, 12, and 24 months after implantation.

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Purpose: Many patients experience oral adverse events during head and neck cancer radiotherapy (RT). The methods of management of such events are under debate. One such technique is the intraoral stent (IOS) technique, which removes normal tissue from the irradiation field.

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Objective: To identify factors significantly associated with quality of life (QOL) and determine if these associations are strong enough to predict certain aspects of QOL without measuring them.

Methods: We conducted an exploratory secondary analysis of baseline data of 224 patients (enrolled between December 2020 and March 2021) from a previously published prospective observational study on radiotherapy for bone metastases at 26 centres. Using univariable linear regression, we assessed the association between patient/treatment factors and QOL scale scores as measured by the European Organization for Research and Treatment of Cancer (EORTC) QOL Questionnaire Core 15-Palliative (QLQ-C15-PAL) and the EORTC QOL Questionnaire Bone Metastases module (QLQ-BM22).

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Purpose: The aim of this study was to understand the income and employment status of patients at the start of and during follow-up after palliative radiation therapy for bone metastasis.

Methods And Materials: From December 2020 to March 2021, a prospective multi-institutional observational study was conducted to investigate income and employment of patients at the start of administration of radiation therapy for bone metastasis and at 2 and 6 months after treatment. Of 333 patients referred to radiation therapy for bone metastasis, 101 were not registered, mainly because of their poor general condition, and another 8 were excluded from the follow-up analysis owing to ineligibility.

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Background: To compare the quality of life (QOL) in patients who underwent robot-assisted radical prostatectomy (RARP) or low-dose-rate brachytherapy (LDR-BT) for prostate cancer.

Methods: We enrolled patients who underwent LDR-BT (LDR-BT alone [n = 540] or LDR-BT plus external beam radiation therapy [n = 428]) and RARP (n = 142). QOL was evaluated using the International Prostate Symptom Score, Expanded Prostate Cancer Index Composite (EPIC), Sexual Health Inventory for Men (SHIM), and 8-item Short Form (SF-8) health survey.

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Objectives: To evaluate prognostic factors of biochemical recurrence (BCR) in each risk group of prostate cancer patients who underwent low-dose-rate brachytherapy (LDR-BT).

Methods: A total of 944 patients with clinically confirmed prostate cancer (cT1c-3aN0M0) who had underwent LDR-BT were enrolled. The low-, intermediate-, and high-risk groups included 278, 498, and 168 patients, respectively.

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We compared clinical outcomes associated with seed brachytherapy (SEED-BT) alone and SEED-BT plus external-beam radiotherapy (EBRT) for intermediate-risk prostate cancer using propensity score-matched analysis. From 2006 to 2011, 993 patients diagnosed with intermediate-risk were treated with either SEED-BT alone (n = 775) or SEED-BT plus EBRT (n = 158) at 3 tertiary hospitals. In the propensity score-matched analysis (102 pairs), median follow-up was 95 months (range 18-153 months).

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Objectives: To evaluate late genitourinary (GU) and gastrointestinal (GI) toxicities and radiation-induced second primary cancers (RISPCs) in patients who received low-dose-rate brachytherapy (LDR-BT) with or without external beam radiotherapy for prostate cancer.

Methods: This retrospective study included 897 consecutive patients who received LDR-BT between July 2004 and July 2015 in our institution. Adverse events and the incidence of second primary cancers were evaluated at 1, 3, 6, 12, 18, 24, 30, 36, 48, 54, and 60 mo after LDR-BT and then once a year.

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Background: We compared the oncological outcomes of patients who received seed brachytherapy (SEED-BT) with those who received radical prostatectomy (RP) for intermediate-risk prostate cancer.

Methods: Candidates were patients treated with either SEED-BT (n = 933) or RP (n = 334). One-to-one propensity score matching was performed to adjust the patients' backgrounds.

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Article Synopsis
  • The study aimed to assess the effects of combining mirabegron with tamsulosin on urinary symptoms in prostate cancer patients post I-brachytherapy.
  • Patients were randomly assigned to either a combination therapy group or a tamsulosin-only group, with several urinary metrics evaluated after 3 months.
  • Results showed no significant improvement in total voided volume when comparing the two groups, but the combination therapy did decrease overactive bladder symptoms and urinary frequency.
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Objective: Higher quality of postimplant dosimetric evaluation is associated with higher biochemical recurrence-free survival rates after low-dose-rate brachytherapy for localized prostate cancer. Postimplant prostate D90 is a key dosimetric parameter showing the quality of low-dose-rate brachytherapy. In this study, to improve the quality of low-dose-rate brachytherapy for localized prostate cancer, we investigated pre-implant factors affecting the reduction of postimplant prostate D90.

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This study evaluated erectile function and sexual quality of life (QoL), and predictive factors for erectile dysfunction (ED) and the deterioration of sexual QoL in 70 patients who underwent low-dose-rate brachytherapy (LDR-BT) alone for prostate cancer without androgen deprivation therapy. Erectile function and sexual QoL were evaluated before and 1, 3, 6, 12, 24, 36, 48 and 60 months after LDR-BT. Binary logistic regression analysis was used to determine whether age, prostate volume, hypertension, diabetes, Brinkman's index, testosterone, baseline Sexual Health Inventory for Men (SHIM) score and post-implant dosimetry parameters could predict ED and deterioration of sexual QoL at 24 and 60 months after LDR-BT.

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Objectives: To compare the effects of naftopidil and silodosin administration on the quality of life of patients with prostate cancer who underwent low-dose-rate brachytherapy.

Methods: In total, 141 men diagnosed with localized prostate cancer who were treated with low-dose-rate brachytherapy were enrolled. Patients were randomized (1:1) to the naftopidil (75 mg/day, n = 63) or silodosin group (8 mg/day, n = 64).

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Objectives: Lower urinary tract symptoms are transiently exacerbated by low-dose-rate brachytherapy (LDR-BT) for prostate cancer and recover to pretreatment levels 1 year thereafter. Generally, these symptoms are influenced by temperature. We aimed to search for factors affecting the lower urinary tract symptoms after seed implant including seasons.

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Objectives: To compare the dose evaluation parameters between conventional (using loose seed alone) and hybrid (using loose seeds in combination with stranded seeds) low-dose rate brachytherapy for prostate cancer.

Methods: Between 2014 and July 2016, a total of 219 patients who underwent low-dose rate brachytherapy were enrolled in a randomized controlled trial (trial number: UMIN 000012780). Patients were randomized and allocated to two groups (conventional method vs hybrid method).

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Background: Radiotherapy is one of the most frequently selected treatment options for patients with prostate cancer. However, adverse effects related to the irradiated surrounding normal organs are significant clinical concerns. Specifically, genitourinary and gastrointestinal toxicities can lead to a dramatically reduced quality of life.

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Objectives: To evaluate the use of cyclooxygenase-2 inhibitors in patients receiving low-dose-rate brachytherapy for prostate cancer.

Methods: A total of 310 patients with prostate cancer (cT1c-3aN0M0) who received low-dose-rate brachytherapy between May 2010 and July 2013 were enrolled and allocated to one of the two treatment groups (tamsulosin alone 0.2 mg/day for 6 months vs tamsulosin 0.

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Purpose: The goal of this study was to evaluate the effect of cyclooxygenase-2 (COX-2) inhibitors on quality of life (QoL) of patients undergoing low-dose-rate (LDR) brachytherapy.

Material And Methods: A total of 310 patients with prostate cancer who had undergone LDR brachytherapy were enrolled. The patients were randomized (1 : 1) to the monotherapy group (tamsulosin alone: 0.

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