Upper rectal fixation with an endorectal balloon in prostate cancer radiotherapy.

Purpose: Despite the efficacy of endorectal balloon (ERB) in reducing rectal radiation dose, the effectiveness of upper rectal fixation remains to be evaluated. The purpose of this study was to evaluate the impact of ERB on upper rectal fixation in patients diagnosed with localized prostate cancer.

Materials: Cine MRI was performed in 46 patients with localized prostate cancer to assess the stability of the anterior rectal wall with and without ERB by calculating the standard deviation of the normalized signal intensity at the level of the midgland or the seminal vesicle.

The Effects of Boron Neutron Capture Therapy on the Lungs in Recurrent Breast Cancer Treatment.

Boron neutron capture therapy (BNCT) has predominantly been performed for brain tumors or head and neck cancers. Although BNCT is known to be applicable to breast cancer, it has only been performed in a few cases involving thoracic region irradiation with reactor-based BNCT systems. Thus, there are very few reports on the effects of BNCT on the thoracic region and no reports of BNCT for breast cancer with accelerator-based BNCT systems.

High-dose planned adaptive helical tomotherapy for cutaneous angiosarcoma of the scalp.

Purpose: The purpose of this study was to investigate the feasibility and effectiveness of high-dose planned adaptive intensity-modulated radiation therapy (IMRT) with helical tomotherapy (HT) for cutaneous angiosarcoma (cAS) of the scalp.

Methods: This retrospective cross-sectional included a total of 12 consecutive patients with cAS of the scalp who underwent high-dose planned adaptive IMRT with HT. Prescribed doses were 72.

Long-term follow-up results of endorectal balloon-assisted helical tomotherapy for localized prostate cancer patients in the high-risk group of gastrointestinal adverse events.

Background: Endorectal balloon (ERB) has been shown to reduce rectal radiation dose and late gastrointestinal toxicities in patients with prostate cancer. However, the usefulness of ERBs for patients with prostate cancer whose rectal shape or size is suboptimal has not been investigated. The purpose of this study was to present the long-term follow-up results of ERB-assisted helical tomotherapy for localized prostate cancer patients whose initial radiation treatment planning (RTP) was unacceptable due to suboptimal rectal shape or size.

MRI-guided stereotactic ablative radiation therapy for liver metastasis from pancreatic cancer.

A 69-year-old man with a history of pancreatic cancer was referred to our hospital for a newly developed solitary liver metastasis. Since the liver metastasis was in contact with the small intestine, it was necessary to perform radiation therapy while simultaneously monitoring the small intestine and liver metastasis, and then, MRI-guided stereotactic ablative radiation therapy (SABR) was performed. There were no radiation-induced adverse events during the treatment and 6 months of follow-up.

Tomotherapy: Comparison of Hi-ART, Tomo-HD, and Radixact.

Aim In this study, we compared three generations of tomotherapy (Hi-ART, Tomo-HD, and Radixact). This is to study the difference among tomotherapy systems in terms of dose distribution to planning target volume and organs at risk, and irradiation time.  Materials and methods The treatment planning CT and contour information used were seven cases of rectum cancer pre-operative irradiation.

Quantitative evaluation of volume change of perirectal hydrogel spacer by Dixon-based water-only images.

Purpose: There are no detailed data on volume changes of SpaceOAR hydrogel spacer. The purpose of this study was to quantitatively evaluate the volume changes of SpaceOAR during radiation therapy for prostate cancer.

Materials: The volume of SpaceOAR in seven prostate cancer patients was quantitatively measured every two weeks by Dixon-based water-only MRI scans.

MRI findings of iatrogenic extravasation of gadolinium-based contrast agents in patients with cancer.

Background: Magnetic resonance imaging (MRI) findings after subcutaneous extravasation of gadolinium-based contrast agent (GBCA) have not been investigated in detail.

Purpose: To present the MRI findings of iatrogenic extravasation and to evaluate the characteristic findings.

Material And Methods: In this retrospective study of 16,039 patients with cancer, 11 patients had significant extravasation of macrocyclic GBCA, and 7 of the 11 had MRI of the injection site.

SPIO-enhanced 0.35T MRI-guided radiotherapy for liver malignancies: usefulness in tumor visualization.

Objectives: The purpose of this study was to investigate the changes of tumor-to-liver signal ratio in a 0.35T MRI-guided radiotherapy system and to evaluate the usefulness and pitfalls of superparamagnetic iron oxide (SPIO) administration for visualization of liver tumors.

Methods: Forty-two patients treated with MRI-guided stereotactic ablative radiotherapy (SABR) for liver tumors were included in this study.

High-Dose Planned Adaptive Intensity-Modulated Radiation Therapy with Simultaneous Integrated Boost for Synchronous Oligometastatic Pancreatic Cancer.

The purpose of this study was to investigate the efficacy and feasibility of high-dose (72.6 Gy) planned adaptive intensity-modulated radiation therapy (IMRT) with simultaneous integrated boost (SIB) for 9 consecutive patients with synchronous oligometastatic pancreatic ductal adenocarcinoma (PDAC). The estimated 2-year overall survival rate was 66.

Multiparametric MRI-guided Hypofractionated Intensity-modulated Radiation Therapy With Simultaneous Integrated Boost for Glioblastoma.

Background/aim: This study investigated the feasibility and efficacy of multiparametric magnetic resonance imaging (MRI)-guided dose-escalated hypofractionated intensity-modulated radiation therapy with simultaneous integrated boost (IMRT-SIB) for glioblastoma.

Patients And Methods: Eighteen patients underwent postoperative IMRT-SIB for glioblastoma using three MRI sequences: double inversion recovery (DIR), diffusion tensor imaging (DTI), and post-gadolinium T1-weighted imaging. Prescribed doses were 60 Gy and 40 Gy in 15 fractions for residual enhancing lesions and surrounding tumor-infiltrating areas, respectively.

Superparamagnetic iron oxide-enhanced MRI-guided stereotactic ablative radiation therapy for liver metastasis.

Background: MRI-guided radiation therapy can image a target and irradiate it at the same time. Superparamagnetic iron oxide (SPIO) is a liver-specific contrast agent that can selectively visualize liver tumors, even if plain MRI does not depict them. The purpose of this study was to present a proof of concept of SPIO-enhanced MRI-guided radiation therapy for liver tumor.

Comparison of gross tumor volumes of pulmonary metastasis defined by CT and MRI in 0.345 T MRI-guided radiotherapy.

Objective: To assess the difference in gross tumor volumes (GTVs) defined by CT (GTV-CT) and by low magnetic field strength (0.345 T) MRI (GTV-MRI) in patients simulated for MRI-guided radiotherapy forlung metastasis.

Methods: 28 patients (148 lesions) who underwent CT and MRI simulation with the tri-60Co MRI-guided radiotherapy system (MRIdian, ViewRay) were included in this study.

Pancytopenia due to massive bone marrow carcinomatosis after radiotherapy for locally advanced breast cancer.

Pancytopenia is a rare complication among patients with breast cancer. Here, we report a case of pancytopenia due to massive bone marrow carcinomatosis (BMC) developed after local radiotherapy following to mastectomy. A 48-year-old woman with locally advanced breast cancer underwent mastectomy and axillary lymph node dissection.

Dual-Energy Spectral CT: Various Clinical Vascular Applications.

Single-source dual-energy (DE) computed tomography (CT) with fast switching of tube voltage allows projection-based image reconstruction, substantial reduction of beam-hardening effects, reconstruction of accurate monochromatic images and material decomposition images (MDIs), and detailing of material composition by using x-ray spectral information. In vascular applications, DE CT is expected to overcome limitations of standard single-energy CT angiography, including patient exposure to nephrotoxic contrast medium and carcinogenic radiation, insufficient contrast vascular enhancement, interference from metallic and beam-hardening artifacts and severe vessel calcification, and limited tissue characterization and perfusion assessment. Acquisition of low-energy monochromatic images and iodine/water MDIs can reasonably reduce contrast agent dose and improve vessel enhancement.

Whole-Body Clinical Applications of Digital Tomosynthesis.

With flat-panel detector mammography, radiography, and fluoroscopy systems, digital tomosynthesis (DT) has been recently introduced as an advanced clinical application that removes overlying structures, enhances local tissue separation, and provides depth information about structures of interest by providing high-quality tomographic images. DT images are generated from projection image data, typically using filtered back-projection or iterative reconstruction. These low-dose x-ray projection images are easily and swiftly acquired over a range of angles during a single linear or arc sweep of the x-ray tube assembly.

Current and Novel Imaging Techniques in Coronary CT.

Multidetector coronary computed tomography (CT), which is widely performed to assess coronary artery disease noninvasively and accurately, provides excellent image quality. Use of electrocardiography (ECG)-controlled tube current modulation and low tube voltage can reduce patient exposure to nephrotoxic contrast media and carcinogenic radiation when using standard coronary CT with a retrospective ECG-gated helical scan. Various imaging techniques are expected to overcome the limitations of standard coronary CT, which also include insufficient spatial and temporal resolution, beam-hardening artifacts, limited coronary plaque characterization, and an inability to allow functional assessment of coronary stenosis.

Influence of the motion correction algorithm on the quality and interpretability of images of single-source 64-detector coronary CT angiography among patients grouped by heart rate.

Purpose: We retrospectively investigated the effect of the motion correction algorithm (MCA) on image quality and interpretability by heart rate (HR) in coronary CT angiography (CCTA).

Materials And Methods: For 105 patients (6 HR groups) undergoing CCTA, 2 readers independently graded the image quality of the 4 major coronary arteries reconstructed with and without MCA at diastole with HR ≤64 bpm and at systole and diastole ≥65 bpm using a 5-point scale. For each HR group and cardiac phase, we compared per-vessel and per-segment image quality using Wilcoxon signed rank test and percentages of interpretable image quality (scores 3-5) among without MCA at diastole with HR ≤64 bpm, as a reference, with MCA at diastole ≤69 bpm and at systole 70-79 bpm using the chi-square test.

A method for selecting a protocol for routine body CT scan using Gemstone Spectral Imaging with or without adaptive statistical iterative reconstruction: phantom experiments.

Purpose: To investigate a method for selecting a protocol for body CT scan to acquire monochromatic images (MIs) by gemstone spectral imaging (GSI) with or without adaptive statistical iterative reconstruction (ASiR).

Materials And Methods: We subjected a phantom to conventional scanning at 120 kVp and 50-700 mAs and GSI at 165-600 mAs; reconstructed MIs at 65 keV with ASiR 0-100 % for GSI; placed 5 regions of interest on each of 3 consecutive reconstructed slices to obtain the averaged standard deviation (SD) as image noise for conventional scan and GSI. Linear regression analysis yielded the mAs by conventional scan that could be used to achieve similar image noise by GSI.

[Feasibility of early ambulation three hours after transfemoral angiography using a 4 French sheath].

Purpose: Our objective was to evaluate the feasibility of early resumption of ambulation 3 hours after transfemoral angiography using a 4 French sheath.

Subjects And Methods: This prospective study was carried out in a selected group of men and women without impaired blood clotting (prothrombin time > 15 sec) or thrombocytopenia (platelet < 55,000/mm3). The subjects consisted of 66 men and 34 women with a mean age of 62.