Constrained optimization towards marker-based tumor tracking in VMAT.

This study proposes that incorporating marker-based visibility constraints into the optimization of volumetric modulated arc therapy (VMAT) will generate treatment plans which not only ensure a higher chance of successfully applying real-time tumor tracking techniques, but also simultaneously satisfy dosimetric objectives. This was applied clinically and investigated for multiple disease sites (10 prostate, 5 liver, and 5 lung) using a radiotherapy optimization software (), where these new constraints were added to conventional dosimetric constraints. For all the investigated sites, three fiducial markers were located inside or around the planning target volume (PTV), and VMAT plans were created for each patient.

Feasibility study for marker-based VMAT plan optimization toward tumor tracking.

This work investigates the incorporation of fiducial marker-based visibility parameters into the optimization of volumetric modulated arc therapy (VMAT) plans. We propose that via this incorporation, one may produce treatment plans that aid real-time tumor tracking approaches employing exit imaging of the therapeutic beam (e.g.

Objective performance assessment of five computed tomography iterative reconstruction algorithms.

Objective: Iterative algorithms are gaining clinical acceptance in CT. We performed objective phantom-based image quality evaluation of five commercial iterative reconstruction algorithms available on four different multi-detector CT (MDCT) scanners at different dose levels as well as the conventional filtered back-projection (FBP) reconstruction.

Methods: Using the Catphan500 phantom, we evaluated image noise, contrast-to-noise ratio (CNR), modulation transfer function (MTF) and noise-power spectrum (NPS).

The effect of different bleaching wavelengths on the sensitivity of Al(2)O(3):C optically stimulated luminescence detectors (OSLDs) exposed to 6 MV photon beams.

Purpose: To determine the effect of different bleaching wavelengths on the response of Al(2)O(3):C optically stimulated luminescence detectors (OSLDs) exposed to accumulated doses of 6 MV photon beams.

Methods: In this study the authors used nanoDot OSLDs readout with a MicroStar reader. The authors first characterized the dose-response, fading, and OSL signal loss of OSLDs exposed to doses from 0.