Publications by authors named "Koji Inaba"

Background: To analyze in a prospective study the long-term safety and efficacy of 3-dimensional conformal radiotherapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI) for Japanese women with early breast cancer.

Methods: Breast cancer patients with pathological tumor size ≤ 3 cm, age ≥ 20 years, lumpectomy with at least a 5 mm margin, and ≤ 3 positive axillary nodes were eligible. APBI was delivered by 3D-CRT at a dose of 38.

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Background: To protect the rectum and bladder from high dose exposure, the Japanese guidelines for managing uterine cervical carcinoma recommend pelvic irradiation with central shielding (CS). Conversely, the European Society for Radiotherapy and Oncology (ESTRO) and the American Brachytherapy Society (ABS) guidelines recommend delivering ≥85 Gy to high-risk clinical target volume D (CTV D). In this study, we investigated whether a gel spacer can enable the safe delivery of the ESTRO/ABS-recommended doses to the target while observing dose constraints for the OARs without using CS in external beam radiation therapy (EBRT).

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Background: The aim of this multi-institutional phase II study was to confirm the safety and the potential efficacy of moderately hypofractionated intensity-modulated radiotherapy (IMRT) with prostate-based image-guidance for Japanese patients.

Methods: Patients with low- or intermediate-risk localized prostate cancer were eligible. Patients with a part of high risk (having only one of the following factors, cT3a, 20 < PSA ≤ 30, or GS = 8 or 9) were also included.

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  • * A 73-year-old woman with cervical cancer received targeted radiation treatment, where traditional methods fell short due to the proximity of her sigmoid colon, necessitating the injection of hydrogel into the meso-sigmoid.
  • * Results showed that using the hydrogel spacer successfully decreased the radiation dose to the sigmoid colon while still effectively targeting the high-risk areas of cancer, suggesting it as a viable technique for similar cases.
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  • Radiation therapy can cause late adverse events due to difficulties in adhering to dose constraints for normal tissue, with spacers potentially reducing radiation exposure to surrounding healthy tissues during gynecologic brachytherapy.
  • Variability in tissue resistance affects the placement of spacers, with different tissues offering unique characteristics that can be utilized in surgical procedures, such as pelvic organ prolapse surgery and radical hysterectomies.
  • Effective spacer injection can improve patient safety and therapy effectiveness, requiring precision and proper anatomical understanding during administration.
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  • This study presents the first case of using a linear accelerator-based boron neutron capture therapy (BNCT) system to treat a patient with cutaneous malignant melanoma in a clinical trial that started in November 2019.
  • A patient with a localized melanoma who opted out of surgery and chemotherapy received BNCT after being administered boronophenylalanine (BPA), leading to a gradual improvement in their condition over 12 months.
  • While the patient experienced some mild side effects, there were no serious adverse events, indicating that accelerator-based BNCT could be a promising new treatment option for this type of cancer.
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  • The study focused on tracking the movements of the uterus during radiation treatment in patients with cervical cancer, using MR imaging to analyze changes in uterus and cervix positioning as well as bladder and rectal volume effects.
  • Findings indicated that the uterus moved more than the cervix and was more closely linked to bladder movements, which could affect treatment dosage.
  • The research underlines the importance of adjusting treatment plans in real-time for moving organs, suggesting that personalized planning is necessary to ensure effective radiation delivery, though this can lead to longer treatment times.
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Background And Purpose: Ultrahypofractionated radiation therapy is increasingly used in the treatment of prostate cancer. High-dose-rate brachytherapy (HDR-BT) and stereotactic body radiotherapy (SBRT) are representative methods of ultrahypofractionation. This study was performed to compare clinically applied treatment plans for patients who had been treated using HDR-BT vs.

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Purpose: We investigated the long-term oncological outcome of high-dose-rate (HDR) multicatheter interstitial brachytherapy (MIB) for adjuvant accelerated partial breast irradiation (APBI) after breast conserving surgery in Japanese patients.

Material And Methods: Between June 2002 and October 2011, 86 breast cancer patients were treated at National Hospital Organization Osaka National Hospital (trial number of the local institutional review board, 0329). Median age was 48 years (range, 26-73 years).

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Objective: Compared with the implementation speed of image-guided adaptive brachytherapy for uterine cervical cancer, that of intracavitary and interstitial brachytherapy is slow, possible because it requires more invasive procedure of inserting needles directly into tumours. To accelerate the implementation speed of intracavitary and interstitial brachytherapy, a first hands-on seminar for image-guided adaptive brachytherapy and intracavitary and interstitial brachytherapy for uterine cervical cancer was held on 26 November 2022, supported by Japanese Society for Radiology and Oncology. This article deals with this hands-on seminar and difference of degree of confidence of participants in starting intracavitary and interstitial brachytherapy before and after the seminar.

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  • Concurrent chemoradiotherapy (CCRT) is the standard treatment for locally advanced non-small cell lung cancer (LA-NSCLC), and the PACIFIC trial established durvalumab as an effective post-CCRT therapy.
  • This study analyzed data from 113 Japanese LA-NSCLC patients treated with CCRT and durvalumab, focusing on survival outcomes and prognostic factors.
  • Key findings indicate that factors like pretreatment ILA scores, adenocarcinoma type, and patient performance status significantly affect overall survival (OS) in patients receiving this combination therapy.
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Objective: The purposes of this trial were to demonstrate the feasibility and effectiveness of the hybrid of intracavitary and interstitial brachytherapy (HBT) for locally advanced cervical cancer patients in the phase I/II prospective clinical trial.

Methods: Patients with FIGO stage IB2-IVA uterine cervical cancer pretreatment width of which was ≥5 cm measured by magnetic resonance imaging were eligible for this clinical trial. The protocol therapy included 30-30.

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  • - Scalp angiosarcoma is a rare and aggressive cancer where definitive radiotherapy can be a treatment option, but its impact on overall survival (OS) and cancer-specific survival (CSS) when combined with local treatment effects is not fully understood.
  • - A study analyzing 31 patients who underwent radiotherapy found that over half experienced local recurrence, with recurrences within 6 months significantly affecting survival outcomes.
  • - The results indicated that local recurrence not only decreased the patients’ OS and CSS but also led to severe symptoms, negatively impacting their quality of life.
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This study aimed to clarify the differences in radiotherapy dose characteristics and delivery efficiency between the supine and prone positions in patients with prostate cancer using the CyberKnife. The planning computed tomography (CT) and delineations of the prone position were obtained by rotating the supine CT images with delineations of 180° using image processing software. The optimization parameters for planning target volume (PTV) and organs at risk (OARs) were based on the prone position.

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Purpose: The clinical characteristics and prognosis of HPV-related nasopharyngeal cancer (NPC) remain controversial. The relationship between p16 status and outcome was retrospectively investigated in the NPC patients.

Materials And Methods: Between May 2009 and May 2019, 81 NPC patients who received definitive radiation therapy, in a hospital in Japan, were identified and the prognosis was investigated.

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Background: Although radical prostatectomy is associated with good long-term oncological outcomes, approximately 30% of patients present biochemical recurrence, whereupon salvage treatments are required. Identification of novel molecular biomarkers to predict cancer behavior is clinically important. Here, we developed a novel microRNA (miRNA)-based prognostic model for patients who underwent radical prostatectomy.

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The first magnetic resonance (MR)-guided radiotherapy system in Japan was installed in May 2017. Implementation of online MR-guided adaptive radiotherapy (MRgART) began in February 2018. Online MRgART offers greater treatment accuracy owing to the high soft-tissue contrast in MR-images (MRI), compared to that in X-ray imaging.

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Purpose: Pelvic sidewall recurrence after hysterectomy for uterine malignances has a poor prognosis, and the salvage therapy for this type of recurrence is still challenging. The purpose of this study was to investigate the efficacy of freehand high-dose-rate interstitial brachytherapy (HDR-ISBT) through the perineum using transrectal ultrasonography for this disease.

Methods And Materials: We retrospectively evaluated 42 patients with pelvic sidewall recurrence after hysterectomy for uterine cervical and endometrial cancers.

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Purpose: Hyaluronate gel has been injected as a spacer into the rectovaginal fossa and vesicouterine fossa during brachytherapy for patients with cervical cancer at our institution. The effect of hyaluronate gel injection (HGI) on dose-volume parameters was investigated in this study.

Methods And Materials: Between July 2008 to January 2020, a total of 104 patients (non-HGI group: 52 patients; HGI group: 52 patients) who underwent curative radiation therapy for cervical cancer were selected.

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Background: Validity of the risk classification by Ang for human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) remains to be studied in the patients treated by modalities other than chemoradiotherapy and in Japanese patients.

Materials And Methods: Between 2010 and 2018, 122 patients with HPV-related OPSCC in stages III and IV by the TNM classification 7th edition (TNM-7) were treated curatively at a single institution in Japan. The median age was 62.

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Objective: This is the preliminary results of a multi-center prospective clinical trial evaluating the feasibility of the hybrid of intracavitary and interstitial brachytherapy for locally advanced cervical cancer.

Methods: Patients with FIGO stage IB2, IIA2, IIB, IIIA, IIIB and IVA uterine cervical cancer pretreatment width of which was ≥5 cm measured by MRI were eligible. Protocol therapy consisted of 30-30.

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  • Cutaneous angiosarcomas (SAs) are rare and aggressive skin cancers with low survival rates, making effective treatment challenging.
  • This study evaluated the safety and effectiveness of using advanced radiotherapy techniques, specifically intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT), to treat localized SAs that are 5 cm or larger.
  • Results showed that 2-year survival rates were low, with 41.8% overall survival, high instances of acute radiation dermatitis among patients, and specific factors like tumor bleeding and invasion impacting survival outcomes.
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Purpose: This study reports the first-in-human use of a linear accelerator-based boron neutron capture therapy (BNCT) system and the first treatment of patients with scalp-angiosarcoma with accelerator-based BNCT.

Patients And Methods: A single-center open-label phase I clinical trial has been conducted using the system since November 2019. Patients with a localized node-negative scalp-angiosarcoma along with the largest diameter of the tumor ≤ 15 cm who refused primary surgery and chemotherapy were enrolled.

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Purpose: The purpose of this study was to evaluate the effect of a lead block for alveolar bone protection in image-guided high-dose-rate interstitial brachytherapy for tongue cancer.

Material And Methods: We treated 6 patients and delivered 5,400 cGy in 9 fractions using a lead block. Effects of lead block (median thickness, 4 mm) on dose attenuation by distance were visually examined using TG-43 formalism-based dose distribution curves to determine whether or not the area with the highest dose is located in the alveolar bone, where there is a high-risk of infection.

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Article Synopsis
  • This study focused on patients with recurrent gynecologic cancers who had previously undergone pelvic irradiation and received salvage re-irradiation through image-guided high-dose-rate brachytherapy (IG-HDR-BT) between June 2014 and March 2020.
  • A total of 37 patients participated, with the majority having uterine cervical cancer, and the study reported a median follow-up of 15.4 months, showing overall survival at 68.9% and progression-free survival at 49.3%.
  • Results indicated that significant late side effects occurred in 24.3% of cases, particularly linked to the use of bevacizumab and larger tumor sizes, suggesting that IG-HDR-BT could
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