Purpose: To investigate a novel bioimpedance-based respiratory gating system (BRGS) designed for external beam radiotherapy and to evaluate its technical characteristics in comparison with existing similar systems.
Materials And Methods: The BRGS was tested on three healthy volunteers in free breathing and breath-hold patterns under laboratory conditions. Its parameters, including the time delay (TD) between the actual impedance change and the gating signal, temperature drift, root mean square (RMS) noise, and signal-to-noise ratio (SNR), were measured and analyzed.
Purpose: To evaluate intrafractional motion effects as a function of peak-to-peak motion and period during single-field, single-fraction and single-field, multifraction irradiation of the moving target in spot-scanning proton therapy.
Materials And Methods: An in-house dynamic phantom was used to simulate peak-to-peak motion of 5, 10, and 20 mm with periods of 2, 4, and 8 seconds. The dose distribution in the moving target was measured using radiochromic films.
Purpose: To investigate a novel optical markerless respiratory sensor for surface guided spot scanning proton therapy and to measure its main technical characteristics.
Methods: The main characteristics of the respiratory sensor including sensitivity, linearity, noise, signal-to-noise, and time delay were measured using a dynamic phantom and electrical measuring equipment on a laboratory stand. The respiratory signals of free breathing and deep-inspiration breath-hold patterns were acquired for various distances with a volunteer.