The Development of Volumetric Quantitative Evaluation Software for Assessing Respiratory-Induced Target Motion.

Purpose We developed a volumetric quantitative evaluation software called vector volume histogram (VVH) to evaluate respiratory-induced organ motion using deformable image registration (DIR). Methods The B-spline-based DIR algorithm was used to compute the deformation vector field (DVF), which included the DVF (left-right), DVF (anterior-posterior), and DVF (craniocaudal). The VVH software was written as a plug-in using Python, thus allowing anyone to easily modify the code.

An In-Bore Audio-Visual Respiratory Coaching Projector for Ring Gantry Systems.

We have proposed an in-bore audio-visual respiratory coaching projector for use with ring gantry linacs and four-dimensional computed tomography (4D CT) systems. A respiratory coaching application was installed on a commercially available mobile projector that includes a computer. The projector was placed on a patient couch, with the projected movie displayed on the inner wall of the bore.

Optimal threshold of a control parameter for tomotherapy respiratory tracking: A phantom study.

Background: Radixact Synchrony , a real-time motion tracking and compensating modality, is used for helical tomotherapy. Control parameters are used for the accurate application of irradiation. Radixact Synchrony uses the potential difference, which is an index of the accuracy of the prediction model of target motion and is represented by a statistical prediction of the 3D distance error.

[Usefulness of an Ultrasound System with Automatic Bladder Urine Volume Measurement Using Artificial Intelligence Technology in Radiotherapy].

Purpose: We aimed to investigate the usefulness of iViz air ver.4 Convex (FUJIFILM, Tokyo) as a tool to determine the bladder capacity before prostate radiotherapy by comparing it with the existing BladderScan BVI 6100 (Verathon Inc., Bothell, Washington).

Error Detectability of Isodose Volumes as ROIs in Prostate Intensity-modulated RT QA.

Background/aim: To evaluate the quality of error detectability with a three-dimensional verification system using isodose volumes as regions of interest (ROIs) in quality assurance (QA) of intensity-modulated radiation therapy.

Patients And Methods: Treatment plans with four types of intentional errors were created from the data of 20 patients with localized prostate cancer. These plans underwent QA using the three-dimensional verification system.

Risk factors for radiation pneumonitis after rotating gantry intensity-modulated radiation therapy for lung cancer.

The risk factors for severe radiation pneumonitis (RP) in patients with lung cancer who undergo rotating gantry intensity-modulated radiation therapy (IMRT) using volumetric modulated arc therapy (VMAT) or helical tomotherapy (HT) are poorly understood. Fifty-two patients who received rotating gantry IMRT for locally advanced lung cancer were included in this retrospective study. In total, 31 and 21 patients received VMAT and HT, respectively.

Radiation Pneumonitis After Volumetric Modulated Arc Therapy for Non-small Cell Lung Cancer.

Background/aim: To evaluate the incidence and grade of radiation pneumonitis after volumetric modulated arc therapy (VMAT) performed for the treatment of non-small cell cancer (NSCLC).

Patients And Methods: Fifty consecutive non-surgical candidates with NSCLC underwent VMAT. Thirty-five patients had stage-III tumors and 15 had recurrent tumors.

An updating approach for knowledge-based planning models to improve plan quality and variability in volumetric-modulated arc therapy for prostate cancer.

Purpose: The purpose of this study was to compare the dose-volume parameters and regression scatter plots of the iteratively improved RapidPlan (RP) models, specific knowledge-based planning (KBP) models, in volumetric-modulated arc therapy (VMAT) for prostate cancer over three periods.

Methods: A RP1 model was created from 47 clinical intensity-modulated radiation therapy (IMRT)/VMAT plans. A RP2 model was created to exceed dosimetric goals which set as the mean values +1SD of the dose-volume parameters of RP1 (50 consecutive new clinical VMAT plans).

Development and Accuracy Evaluation of Augmented Reality-based Patient Positioning System in Radiotherapy: A Phantom Study.

Background/aim: To develop and evaluate the accuracy of augmented reality (AR)-based patient positioning systems in radiotherapy.

Materials And Methods: AR head-mounted displays (AR-HMDs), which virtually superimpose a three-dimensional (3D) image generated by the digital imaging and communications in medicine (DICOM) data, have been developed. The AR-based positioning feasibility was evaluated.

A first report of tumour-tracking radiotherapy with helical tomotherapy for lung and liver tumours: A double case report.

There are only a limited number of previous reports on clinical cases using tumour tracking with tomotherapy. Therefore, we present two cases of patients treated with tumour tracking with tomotherapy. First, a 74-year-old man with an inoperable lung cancer type T1bN0M0 underwent stereotactic body radiotherapy at a total dose of 48 Gy in four fractions.

Characteristics of a bolus created using thermoplastic sheets for postmastectomy radiation therapy.

This study applied a "shell bolus," an immobilizing thermoplastic shell locally thickened with extra layers over the radiation target, during postmastectomy radiation therapy (PMRT). We performed ion chamber and film measurements for a solid water phantom for thermoplastic sheets and a gel bolus for dosimetric characterization using a 6-MV X-ray flattening-filter-free (FFF) beam. The air gaps between the body surface for the gel and shell bolus were measured using computed tomography (CT) images in patients who underwent PMRT.

Oesophageal Cancer: Conformal Radiotherapy Hybrid-VMAT Technique With Two Different Treatment Planning Systems.

Background/aim: Traditionally, the radiotherapy of oesophageal cancer has been conformal radiotherapy (CRT). We sought to compare dosimetric parameters of conformal radiotherapy (CRT) with those of two treatment planning systems for hybrid-volumetric modulated arc therapy (h-VMAT) for the treatment of oesophageal cancer.

Patients And Methods: In 11 patients, we compared: i) planning target volume coverage, ii) dose to organs at risk, and iii) the dose rate (DR) of the three techniques.

Couch modeling optimization for tomotherapy planning and delivery.

We sought to validate new couch modeling optimization for tomotherapy planning and delivery. We constructed simplified virtual structures just above a default setting couch through a planning support system (MIM Maestro, version 8.2, MIM Software Inc, Cleveland, OH, USA).

Improved error detection using a divided treatment plan in volume modulated arc therapy.

Aim: We sought to improve error detection ability during volume modulated arc therapy (VMAT) by dividing and evaluating the treatment plan.

Background: VMAT involves moving a beam source delivering radiation to tumor tissue through an arc, which significantly decreases treatment time. Treatment planning for VMAT involves many parameters.

Evaluation of local look diffusion tensor imaging for magnetic resonance tractography of the periprostatic neurovascular bundle.

The purpose of this study was to compare diffusion tensor imaging using the local look technique and sensitivity encoding for tractography of the periprostatic neurovascular bundle. We compared the surrounding tissues of the prostate in eight healthy volunteers. The results of tractography in terms of the numbers of fibers and the fractional anisotropy map were evaluated.

[Simulation at Incomplete Acquisition on Stress-rest Cerebral Blood Flow Quantitative Values One Day Method].

The QSPECT dual table autoradiography (DTARG) method can be used for quantitative determination of cerebral blood flow. We verified the influence on quantitative values obtained for cerebral blood flow in the case when usual acquisition was impossible and evaluated those values. Results obtained with an acquisition time of 30 min were considered to be true values, and the correlation and consistency with results of other times were evaluated.

Development of a Three-dimensional Surgical Navigation System with Magnetic Resonance Angiography and a Three-dimensional Printer for Robot-assisted Radical Prostatectomy.

We sought to develop a surgical navigation system using magnetic resonance angiography (MRA) and a three-dimensional (3D) printer for robot-assisted radical prostatectomy (RARP). Six patients with pathologically proven localized prostate cancer were prospectively enrolled in this study. Prostate magnetic resonance imaging (MRI), consisting of T2-weighted sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) and true fast imaging with steady-state precession (true FISP), reconstructed by volume rendering, was followed by dynamic contrast-enhanced MRA performed with a volumetric interpolated breath-hold examination (VIBE) during intravenous bolus injection of gadobutrol.

Pravastatin reduces radiation-induced damage in normal tissues.

Pravastatin is an inhibitor of 3-hydroxy-3-methyl- glutaryl-coenzyme A reductase that has been reported to have therapeutic applications in a range of inflammatory conditions. The aim of the present study was to assess the radioprotective effects of pravastatin in an experimental animal model. Mice were divided into two groups: The control group received ionizing radiation with no prior medication, while the pravastatin group received pravastatin prior to ionizing radiation.

Utility of intraoral stents in external beam radiotherapy for head and neck cancer.

Aim: This study aimed to assess the utility and stability of intraoral stent during intensity-modulated radiation therapy (IMRT).

Background: The benefits of intraoral stents in radiotherapy are unclear.

Materials And Methods: We analyzed 386 setup errors in 12 patients who received IMRT for head and neck cancers without intraoral stents (intraoral stent [-]) and 183 setup errors in 6 patients who received IMRT with intraoral stents (intraoral stent [+]).

Prognostic value of pretreatment volume-based quantitative F-FDG PET/CT parameters in patients with malignant pleural mesothelioma.

Purpose: To investigate the relationships between pretreatment volume-based quantitative F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) parameters and overall survival (OS) in patients with malignant pleural mesothelioma (MPM).

Materials And Methods: We retrospectively reviewed data from 201 MPM patients, of whom 38 underwent surgical resection, and calculated the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), including primary tumors and nodal or distant metastatic lesions, on pretreatment F-FDG PET/CT. Relationships between clinicopathological factors (age, sex, performance status, European Organization for Research and Treatment of Cancer [EORTC] score, histological subtype, TNM stage, and treatment strategy), volume-based quantitative PET/CT parameters, and OS were evaluated using a Cox proportional hazards model and log-rank test.

Radiotherapy in late elderly (aged 75 or older) patients with paranasal sinus carcinoma: a single institution experience.

The purpose of our study was to assess the feasibility of radiotherapy (RT) for locally advanced paranasal sinus carcinomas in late elderly patients (aged ≥75 years) from a single institution in Japan. From 2000 to 2015, we retrospectively analyzed 14 patients (11 maxillary and 3 ethmoid sinus carcinoma patients) who underwent RT for pathologically confirmed paranasal sinus carcinomas. RT was performed without unexpected cessations.

Body mass index can affect gastrointestinal and genitourinary toxicity in patients with prostate cancer treated with external beam radiation therapy.

The aim of the present study was to determine the impact of obesity on radiation-induced gastrointestinal (GI) and genitourinary (GU) toxicity. The cases of 54 patients with prostate cancer, treated with three-dimensional conformal radiation therapy (RT), were reviewed. For each patient, the body mass index (BMI), distance between the prostate and rectum (D) on a computerised tomography scan and the dosimetric parameters of the rectum and bladder in the planning data of RT, were analyzed.