Clinical commissioning and use of the Novalis Tx linear accelerator for SRS and SBRT.

The purpose of this study was to perform comprehensive measurements and testing of a Novalis Tx linear accelerator, and to develop technical guidelines for com-missioning from the time of acceptance testing to the first clinical treatment. The Novalis Tx (NTX) linear accelerator is equipped with, among other features, a high-definition MLC (HD120 MLC) with 2.5 mm central leaves, a 6D robotic couch, an optical guidance positioning system, as well as X-ray-based image guidance tools to provide high accuracy radiation delivery for stereotactic radiosurgery and stereotactic body radiation therapy procedures.

Clinical use of dual image-guided localization system for spine radiosurgery.

The recently released Novalis TX linac platform provides various image guided localization methods including a stereoscopic X-ray imaging technique (ExacTrac) and a volumetric cone beam computed tomography (CBCT) imaging technique. The ExacTrac combined with the robotic six dimensional (6D) couch provides fast and accurate patient setup based on bony structures and offers "snap shot" imaging at any point during the treatment to detect patient motion. The CBCT offers a three dimensional (3D), volumetric image of the patient's setup with visualization of anatomic structures.

Image-guided localization accuracy of stereoscopic planar and volumetric imaging methods for stereotactic radiation surgery and stereotactic body radiation therapy: a phantom study.

Purpose: To evaluate the positioning accuracies of two image-guided localization systems, ExacTrac and On-Board Imager (OBI), in a stereotactic treatment unit.

Methods And Materials: An anthropomorphic pelvis phantom with eight internal metal markers (BBs) was used. The center of one BB was set as plan isocenter.

Severe cytomegalovirus (CMV) community-acquired pneumonia (CAP) in a nonimmunocompromised host.

Background: Community-acquired pneumonia (CAP) in an immunocompetent host may be severe because of a variety or combination of host and microbial factors. In patients with severe cardiopulmonary dysfunction, even relatively avirulent pathogens, that is, Mycoplasma pneumoniae, Moraxella catarrhalis, may compromise borderline cardiac/heart function and present clinically as severe CAP. Alternately, patients with Streptococcus pneumoniae and impaired humoral immunity/splenic dysfunction may present as severe CAP.