Initial Experience of Implementing a Pre-treatment Dry Run for HyperArc Stereotactic Radiosurgery Treatments With Optical Surface Imaging for Intra-fraction Motion Monitoring.

Linac-based stereotactic radiosurgery (SRS) with planning target volume (PTV) margins <1 mm has become increasingly common in recent years. Optical surface imaging for surface-guided radiation therapy (SGRT) is often used for intra-fraction motion monitoring during these treatments to facilitate the use of a smaller PTV margin by providing real-time quantitative patient positioning information. However, rotating the couch introduces errors to SGRT-reported translations and rotations that can be problematic for SRS treatments with non-coplanar arcs and very small PTV margins.

Stereotactic Ablative Radiotherapy for Oligometastatic Pericolonic Soft Tissue Metastases Using Daily Cone-Beam Computed Tomography-Guided Online Adaptive Radiotherapy.

A 74-year-old woman with pathologic T4a N1 M0 adenocarcinoma of the cecum, initially treated with right hemicolectomy, developed rising serum carcinoembryonic antigen levels while receiving adjuvant chemotherapy. Re-staging investigations demonstrated two soft tissue metastases in the right abdomen comprised of a retrocolic lesion immediately posterior to the colon and a retroperitoneal lesion with no other sites of metastases. The patient was treated with stereotactic ablative radiotherapy (SABR) to a dose of 40 Gy in five daily fractions to both pericolonic soft tissue metastases simultaneously.

Semi-automated vertex placement for lattice radiotherapy and dosimetric verification using 3D polymer gel dosimetry.

Purpose: To evaluate the feasibility of an open-source, semi-automated, and reproducible vertex placement tool to improve the efficiency of lattice radiotherapy (LRT) planning. We used polymer gel dosimetry with a Cone Beam CT (CBCT) readout to commission this LRT technique.

Material And Methods: We generated a volumetric modulated arc therapy (VMAT)-based LRT plan on a 2 L NIPAM polymer gel dosimeter using our Eclipse Acuros version 15.

Neural evidence of core foundations and conceptual change in preschool numeracy.

Symbolic numeracy first emerges as children learn the meanings of number words and how to use them to precisely count sets of objects. This development starts before children enter school and forms a foundation for lifelong mathematics achievement. Despite its importance, exactly how children acquire this basic knowledge is unclear.

New pathways to neurogenesis: Insights from injury-induced retinal regeneration.

The vertebrate retina is a tractable system for studying control of cell neurogenesis and cell fate specification. During embryonic development, retinal neurogenesis is under strict temporal regulation, with cell types generated in fixed but overlapping temporal intervals. The temporal sequence and relative numbers of retinal cell types generated during development are robust and show minimal experience-dependent variation.