Replacing gamma knife beam-profiles on film with point-detector scans.

Purpose: Detector arrays and profile-scans have widely replaced film-measurements for quality assurance (QA) on linear accelerators. Film is still used for relative output factor (ROF) measurements, positioning, and dose-profile verification for annual Leksell Gamma Knife (LGK) QA. This study shows that small-field active detector measurements can be performed in the easily accessed clinical mode and that they are an effective replacement to time-consuming and exacting film measurements.

Automatic treatment planning for VMAT-based total body irradiation using Eclipse scripting.

The purpose of this work is to establish an automated approach for a multiple isocenter volumetric arc therapy (VMAT)-based TBI treatment planning approach. Five anonymized full-body CT imaging sets were used. A script was developed to automate and standardize the treatment planning process using the Varian Eclipse v15.

Code of ethics for the American Association of Physicists in Medicine (Revised): Report of Task Group 109.

The American Association of Physicists in Medicine (AAPM) has established a comprehensive Code of Ethics for its members. The Code is a formal part of AAPM governance, maintained as Professional Policy 24, and includes both principles of ethical practice and the rules by which a complaint will be adjudicated. The structure and content of the Code have been crafted to also serve the much broader purpose of giving practical ethical guidance to AAPM members for making sound decisions in their professional lives.

Implementation and validation of an ultrasonic tissue characterization technique for quantitative assessment of normal-tissue toxicity in radiation therapy.

The goal of this study was to implement and validate a noninvasive, quantitative ultrasonic technique for accurate and reproducible measurement of normal-tissue toxicity in radiation therapy. The authors adapted an existing ultrasonic tissue characterization (UTC) technique that used a calibrated 1D spectrum based on region-of-interest analysis. They modified the calibration procedure by using a reference phantom instead of a planar reflector.

Measurements of Radiation-Induced Skin Changes in Breast-Cancer Radiation Therapy Using Ultrasonic Imaging.

Skin injury is a common side effect of breast-cancer radiation therapy. Although physicians often observe skin toxicity, quantifying its severity remains a challenge. We present a novel quantitative ultrasonic technique to evaluate skin changes associated with radiotherapy.

How does performance of ultrasound tissue typing affect design of prostate IMRT dose-painting protocols?

Purpose: To investigate how the performance characteristics of ultrasound tissue typing (UTT) affect the design of a population-based prostate dose-painting protocol.

Methods And Materials: The performance of UTT is evaluated using the receiver operating characteristic curve. As the imager's sensitivity increases, more tumors are detected, but the specificity worsens, causing more false-positive results.

Non-invasive assessment of radiation injury with electrical impedance spectroscopy.

A detailed understanding of non-targeted normal tissue response is necessary for the optimization of radiation treatment plans in cancer therapy. In this study, we evaluate the ability of electrical impedance spectroscopy (EIS) to non-invasively determine and quantify the injury response in soft tissue after high dose rate (HDR) irradiation, which is characterized by large localized dose distributions possessing steep spatial gradients. The HDR after-loading technique was employed to irradiate small volumes of muscle tissue with single doses (26-52 Gy targeted 5 mm away from the source).