MCLogQA is a new TomoTherapy QA process that validates the planned dose before delivery and analyzes the delivered dose using the treatment exit detector and log file data. The MCLogQA procedure is an effective and efficient alternative to traditional phantom-based TomoTherapy plan-specific QA because it allows for comprehensive 3D dose verification, accounts for tissue heterogeneity, uses patient CT density tables, reduces total QA time, and provides for a comprehensive QA methodology for each treatment fraction.

The purpose of this study was to evaluate the visibility and artifact created by gold, carbon, and polymer fiducial markers in a simple phantom across computed tomography (CT), kilovoltage (kV), and megavoltage (MV) linear accelerator imaging and MV tomotherapy imaging. Three types of fiducial markers (gold, carbon, and polymer) were investigated for their visibility and artifacts in images acquired with various modalities and with different imaging parameters (kV, mAs, slice thickness). The imaging modalities include kV CT, 2D linac‐based kilovoltage and megavoltage X‐ray imaging systems, kV cone‐beam CT, and normal and fine tomotherapy imaging. The images were acquired on a phantom constructed using Superflab bolus in which markers of each type were inserted into the center layer. The visibility and artifacts produced by each marker were assessed qualitatively and quantitatively. All tested markers could be identified clearly on the acquired CT and linac‐based kV images; gold markers demonstrated the highest contrast. On the CT images, gold markers produced a significant artifact, while no artifacts were observed with polymer markers. Only gold markers were visible when using linac‐based MV and tomotherapy imaging. For linac‐based kV images, the contrast increased with kV and mAs values for all the markers, with the gold being the most pronounced. On CT images, the contrast increased with kV for the gold markers, while decreasing for the polymer and carbon marker. With the bolus phantom used, we found that when kV imaging‐based treatment verification equipment is available, polymer and carbon markers may be the preferred choice for target localization and patient treatment positioning verification due to less image artifacts. If MV imaging will be the sole modality for positioning verification, it may be necessary to use gold markers despite the artifacts they create on the simulation CT images.PACS number: 87

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Brachytherapy is an important component of multidisciplinary cancer care for a variety of solid tumors. Most systems require moving the patient to multiple locations for treatment planning and delivery after the applicator is placed. A dedicated computed tomography (CT)-on-rails brachytherapy suite was installed at our institution to allow image-guided brachytherapy and a rapid scan-plan-treat workflow that is well suited to a busy quaternary care medical center. The suite consists of an OR couch with CT-compatible insert, a CT-on-rails imaging unit, a Varian Varisource iX HDR afterloader and full anesthesia capabilities. The explicit goal was to provide the ability to perform applicator placement, CT-guided treatment planning, and treatment delivery efficiently and without moving the patient. The dedicated CT-on-rails suite for high-dose-rate brachytherapy offers image-guided brachytherapy capabilities with a rapid workflow that lends itself well to efficient, high-quality care that can meet the demands of a large-volume referral center capable of high patient throughput.