Publications by authors named "Takero Hirata"
Article Synopsis
- Radiotherapy can affect pacemakers and defibrillators, but its impact on patients with left ventricular assist devices (LVAD) is not well understood, prompting this study.
- Three patients in their 50s and 60s with LVADs due to heart conditions underwent stereotactic ablative radiotherapy (SABR) for early-stage lung cancer, with careful planning to limit radiation exposure to the LVAD.
- The treatment was completed without any immediate complications or LVAD malfunctions, and none of the patients experienced disease progression or long-term side effects during follow-up.
Background: Fractionated stereotactic radiosurgery (fSRS) is an important treatment strategy for unresected brain metastases. We previously reported that a good volumetric response 6 months after fSRS can be the first step for local control. Few studies have reported the association between gross tumor volume (GTV) dose, volumetric response, and local control in patients treated with the same number of fractions.
View Article and Find Full Text PDFPurpose: Radiation therapy is widely used to treat head and neck squamous cell carcinoma (HNSCC). This study evaluated the association between circulating plasma programmed death-ligand 1 (PD-L1) and the outcomes of patients with HNSCC after radiation therapy.
Methods And Materials: In this retrospective observational study, plasma samples of 76 patients with HNSCC who underwent radiation therapy from June 2019 to August 2021 were analyzed.
Article Synopsis
- The study developed software to assess how a lead block (LB)-inserted spacer affects the dose of radiation received by the mandible during interstitial brachytherapy for tongue cancer.
- The software used established protocols and Monte Carlo simulations to calculate dose distributions and optimize treatment plans for 30 patients.
- Results showed that considering LB attenuation significantly reduced the radiation dose to the mandible, enhancing treatment safety.
Article Synopsis
- This study aimed to find the safest and most effective dose of stereotactic body radiation therapy (SBRT) for treating prostate cancer.
- Patients were assigned to receive three different doses (35, 37.5, and 40 Gy) and were monitored for side effects and cancer recurrence over two years.
- Results showed that the lowest dose (35 Gy) was associated with fewer late adverse effects compared to higher doses, suggesting that higher doses should be approached carefully.
Article Synopsis
- - The study focuses on the immediate side effects from stereotactic radiotherapy (SRT) for brain metastases, analyzing data from 315 patients treated between May 2019 and February 2022.
- - Out of 439 SRT sessions, only 3.6% of patients experienced significant side effects (Grade ≥ 2), with serious complications (Grade ≥ 3) found in just 1.6% of cases.
- - Findings suggest that while SRT is generally safe, particularly for patients with multiple and large lesions, close monitoring for complications is still essential post-treatment.
Article Synopsis
- The CyberKnife system delivers advanced radiotherapy for metastatic lung tumors through real-time imaging and precise dose gradients, targeting tumor volume while sparing surrounding tissue.
- In a study of 73 patients, results showed promising outcomes with 2-year local control at 89.1% and overall survival at 71.3%, despite some instances of radiation pneumonitis.
- The findings support the effectiveness and safety of using SABR with a central high dose in treating metastatic lung tumors, highlighting minimal serious side effects when targeting fewer lesions.
Background/aim: This study evaluated the effects of the respiratory phase shifts between liver tumor and chest wall motions on the dose distribution for the CyberKnife Synchrony respiratory tracking system (SRTS).
Patients And Methods: Eight patients who received stereotactic body radiotherapy for hepatocellular carcinoma or liver metastases were analyzed. Three-dimensional (3D) motion of the implanted fiducial markers and vertical motion of the sternal bone were derived from the four-dimensional computed tomography (4D-CT) images acquired with a 320-row area detector CT.
Article Synopsis
- The radiation recall phenomenon (RRP) is a rare complication that can occur after radiation therapy, sometimes triggered by treatments like anticancer drugs or COVID-19 vaccines.
- A case study involving a 50-year-old woman showed that after her larynx radiation therapy and treatment with ramucirumab, she experienced RRP, characterized by symptoms like sore throat and mucosal bleeding.
- After receiving the Pfizer-BioNTech COVID-19 vaccine, her symptoms worsened, leading to hospitalization and steroid treatment, highlighting the need to consider RRP as a potential risk when administering vaccines to patients with a history of radiation therapy.
Background/aim: This study aimed to evaluate the treatment outcomes of radiation therapy (RT) for localized prostate cancer in elderly patients aged ≥75 years.
Patients And Methods: We retrospectively investigated data of patients aged ≥75 years with prostate cancer who underwent intensity-modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT) with doses of 70-78 Gy in 35-39 fractions between September 2008 and June 2016. Overall survival (OS), recurrence-free (RF) rates, and occurrence rates of toxicities were calculated.
Article Synopsis
- This study examines the importance of volumetric measurements after stereotactic radiotherapy (SRT) for brain metastases, focusing on substantial volume reductions (over 65% and over 90%) at 6 months post-treatment.
- The analysis of 250 unresected brain metastases reveals that these significant volume reductions are associated with improved local control and are influenced by the dose delivered to the tumor.
- The findings suggest that achieving a higher biological effective dose can be a predictive factor for better volume reduction outcomes, indicating the potential for tailored SRT treatments to enhance effectiveness.
Article Synopsis
- The study evaluated the Lilium® α-200 portable ultrasound bladder scanner to enhance bladder volume (BV) consistency in prostate cancer patients undergoing hypofractionated volumetric modulated arc therapy.
- Fifteen patients had their BV measured with the Lilium scanner, leading to improved correlation (r = 0.796) between BV readings from cone-beam CT (CBCT) and the Lilium device compared to a control group.
- Results showed that the Lilium group experienced significantly fewer variations in bladder dose parameters, indicating that the bladder scanner significantly improved BV reproducibility during treatment.
Background/aim: We evaluated the effectiveness and safety of stereotactic ablative radiotherapy (SABR) delivered using Cyberknife in patients with stage I non-small-cell lung cancer.
Patients And Methods: The clinical results of 153 patients with 161 lung cancers treated with CyberKnife between May 2014 and August 2020 at the Osaka University Hospital were retrospectively analyzed. The median age was 80 years (range=48-99 years).
Previous studies have reported conflicting results for the effect of overall treatment time with stereotactic body radiotherapy on tumor control in early-stage non-small-cell lung cancer. To examine this effect, we conducted a propensity score-weighted, retrospective, observational study at a single institution. We analyzed the data of 200 patients with early-stage non-small-cell lung cancer who underwent stereotactic body radiotherapy (48 Gy in 4 fractions) at our institution between January 2007 and October 2013.
View Article and Find Full Text PDFArticle Synopsis
- The study evaluates the image quality and respiratory motion of hepatocellular carcinoma with portal vein tumor thrombosis (PVTT) using a new imaging technique called contrast-enhanced four-dimensional dual-energy computed tomography (CE-4D-DECT).
- The results show that the optimal virtual monochromatic image (O-VMI) at 60 keV has significantly higher contrast to noise ratio and overall image quality compared to the standard virtual monochromatic image (S-VMI) at 77 keV.
- Additionally, the diaphragm's motion during respiration was found to be greater than that of the tumor, indicating the need for careful localization in radiotherapy to ensure accurate targeting.
In this study, we evaluated the inter-unit variability of the lateral response artifact for multiple flatbed scanners, focusing on the dual-channel method, and investigated the correction method of the lateral non-uniformity. Four scanners with A3+ paper-size and five scanners with A4 paper-size were evaluated. To generate the dose-response curves, small pieces of the Gafchromic EBT3 and EBT-XD films were irradiated, and five of the pieces were repeatedly scanned by moving them on the scanner to evaluate the lateral non-uniformity.
View Article and Find Full Text PDFBackground: Previous studies reported that cigarette smoking during radiation therapy was associated with unfavorable outcomes in various cancers using medical interviewing or monitoring of cotinine. Here, we evaluated the effect of smoking cessation on definitive radiation therapy for early stage glottic carcinoma by monitoring expiratory carbon monoxide (CO).
Material And Methods: We enrolled 103 patients with early glottic carcinoma (T1N0/T2N0 = 79/24) who underwent conventional radiotherapy between 2005 and 2016.
Background/aim: The aim of this retrospective study was to detect the frequency, reasons, and significant factors for not receiving immunotherapy after chemoradiotherapy in non-small cell lung cancer (NSCLC) patients.
Patients And Methods: Thirty-four patients with NSCLC received definitive chemoradiotherapy. The endpoint of this study was receiving durvalumab within 45 days after chemoradiotherapy for NSCLC.
Purpose: This study investigated the characteristics of a new shielded diode detector, microSilicon X (model 60022: MSX), for small-field and large-field dosimetry.
Methods: The percent depth dose (PDD), beam profiles, detector output factor (OF ), temperature dependence, dose rate dependence, dose-per-pulse (DPP) dependence, and dose-response linearity of MSX were evaluated in Cyberknife and TrueBeam photon beams and compared with various detectors including microDiamond (PTW model 60019: MD), Sun Nuclear EDGE detector, Photon diode (PTW model 60016: PD), and semiflex ionization chamber (PTW model 31010: IC).
Results: For field sizes ranging from 50 × 50 mm to 400 × 400 mm , MSX-measured OF values were within 1% of the IC-measured values.
Article Synopsis
- The study focused on using plastic bead bags to achieve uniform total body irradiation (TBI) with dose accuracy within ±10%.
- A specialized TBI bed and a 10 MV photon beam were employed, with multiple corrections and measurements to ensure treatment precision, including in vivo dosimetry.
- Results showed that calculated doses correlated well with measured doses, and the treatment planning system (TPS) can provide rough estimations of patient doses during TBI.
Article Synopsis
- * Among 391 patients treated between 2006 and 2014, a significant number died from various causes, with notable risk factors identified as having a previous surgery for esophageal cancer and receiving simultaneous RT for synchronous esophageal cancer.
- * The findings suggest that while RT can preserve the larynx in HSC patients, it should be approached carefully in those with a history of esophageal cancer-related treatments due to increased risks of non-cancer deaths.
Article Synopsis
- * CT scans showed cancer returning, compressing the left internal carotid artery, leading to a diagnosis of tumor-induced carotid sinus syndrome (tiCSS).
- * After starting palliative intensity-modulated radiotherapy (IMRT), his symptoms improved within ten days, demonstrating that this minimally invasive treatment is a viable option for similar patients with poor prognosis.
Background: The present study aimed to evaluate the toxicity and efficacy of stereotactic body radiotherapy (SBRT) for localized prostate cancer.
Patients And Methods: We investigated 25 patients treated with SBRT of 35 Gy per five fractions from May 2014 to March 2015.
Results: The median age of patients was 70 years, four (16%) patients were low risk and 21 (84%) were intermediate risk.
The prognosis of hepatocellular carcinoma (HCC) with portal vein tumour thrombus (PVTT) is poor. We conducted a prospective study to evaluate the efficacy and safety of tri-modality therapy, including preoperative stereotactic body radiotherapy (SBRT) and surgery, followed by hepatic arterial infusion chemotherapy (HAIC) in HCC patients with PVTT. In this report, we investigated the pathology of the irradiated PVTT specimen in resected cases and SBRT-related acute toxicity.
View Article and Find Full Text PDFBackground: The present study aimed to estimate geometric changes in applicators and prostate over 3 days in patients with high-dose-rate brachytherapy (HDR-BT) and to assess the need for daily replanning.
Patients And Methods: This study retrospectively investigated 18 patients who underwent HDR-BT as monotherapy from February 2016 to October 2018.
Results: Without replanning, the planning target volume coverage significantly worsened on day 2 (p<0.