Interimager variability in ADC measurement of the human brain.

Purpose: Routine clinical practice involves the application of diverse scanning parameters that can affect apparent diffusion coefficient (ADC) values. We evaluated interimager variability in ADC values with respect to their potential effect in clinical applications.

Methods: In 7 healthy volunteers, we obtained diffusion-weighted (DW) images using routine clinical parameters and 1.

Histopathological changes in parotid and submandibular glands of patients treated with preoperative chemoradiation therapy for oral cancer.

We retrospectively evaluated the relationship between computed tomography (CT)- and histopathological findings of parotid and submandibular glands in six patients treated for advanced oral cancer. Eligibility criteria were a pathologic diagnosis of oral squamous cell carcinoma, preoperative chemoradiation therapy (CRT) with a total dose of 30 Gy and oral S-1 (80 mg/m²/day), the availability of morphological assessments by CT and of functional assessments with the Saxon test before- and 2 weeks after CRT, and the availability of histopathological slides of irradiated parotid and submandibular glands. In the histopathological interpretation, gland structures were divided into acinar-, duct-, and adipose cells and other tissues.

FDG-PET/CT-based gross tumor volume contouring for radiation therapy planning: an experimental phantom study.

As there is continuing controversy over the role of F-18-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT-fused imaging in radiation therapy (RT) planning, we performed a phantom study to assess the feasibility of FDG-PET/CT-based gross tumor volume (GTV) contouring. The phantom set, consisting of an elliptical bowl and 6 spheres measuring from 10-37 mm in diameter, were filled with FDG to obtain 3 source-to-background ratios (SBRs) of 4, 8, and 16. The ratio to maximum intensity at 5% intervals was applied as the threshold for contouring.

[Cone-beam computed tomography-derived adaptive radiotherapy].

The purpose of this study was to evaluate the reliability of cone-beam computed tomography (CBCT)-derived adaptive radiotherapy. We evaluate planning computed tomography (pCT) and CBCT in 50 patients who had undergone image guided radiotherapy (IGRT) with CBCT. Irradiated sites included head, neck, chest, abdomen, and pelvis; there were 10 patients in each group.

[Impact of setup error and anatomical change on dose distribution during conventional radiation therapy].

The purpose of this study was to evaluate the impact of setup error and anatomical change on dose distribution during conventional radiation therapy. We performed regional irradiation (Plan1) using opposing pair fields, and then we planned local irradiation (Plan2) with a computed tomography (CT) acquired at that time in 10 patients with advanced oral cancer. To consider the setup error, a minimum dose of gross tumor volume (GTV) and a maximum dose for the spinal cord were re-calculated with isocenter shifts of ±5 mm.

[Computerized estimation of a percent glandular tissue composition in computed radiography mammography].

Measurement of a percent glandular tissue composition (%GTC) is important in terms of the estimation of individual patient exposure dose and the prediction of malignancy, and thus a number of reports for estimating %GTC by use of a mammogram have been published. In this study, we propose a method for estimating individual %GTC by use of computed radiography (CR) mammograms. By employing breast-equivalent phantoms that are able to create breast phantom images with various combinations of fat and glandular tissue, as well as the thickness of whole breast, we determined a reference table for converting an each pixel value on CR mammography to the glandular tissue ratio.