Lhermitte's Sign Developing after IMRT for Head and Neck Cancer

Background. Lhermitte's sign (LS) is a benign form of myelopathy with neck flexion producing an unpleasant electric-shock sensation radiating down the extremities. Although rare, it can occur after head and neck radiotherapy. Results. We report a case of Lhermitte's developing after curative intensity-modulated radiotherapy (IMRT) for a patient with locoregionally advanced oropharyngeal cancer. IMRT delivers a conformal dose of radiation in head and neck cancer resulting in a gradient of radiation dose throughout the spinal cord. Using IMRT, more dose is delivered to the anterior spinal cord than the posterior cord. Conclusions. Lhermitte's sign can develop after IMRT for head and neck cancer. We propose an anterior spinal cord structure, the spinothalamic tract to be the target of IMRT-caused LS

ONLINE FIRST ORIGINAL ARTICLE Evaluating Revascularization and Flap Survival Using Vascular Endothelial Growth Factor in an Irradiated Rat Model

Objective: To evaluate the role of vascular endothelial growth factor (VEGF) plasmid DNA (pDNA) in improving flap revascularization in a previously developed rat model. Our hypothesis was that the uptake and expression of VEGF pDNA in the wound bed would improve revascularization and flap viability. Design: Twenty-eight male Sprague-Dawley rats received a total dose of 40 Gy electron beam radiation to the ventral abdominal wall. After a recovery period, they underwent a ventral fasciocutaneous flap procedure with a 2-hour ischemia period. Group 1 (n=14) received topical VEGF pDNA, in vivo cationic polymer, and fibrin sealant. Group 2 (n=14) received topical cationic polymer and fibrin sealant only. Seven of the rats from each group underwent pedicle ligation at 8or14days.Theprimaryoutcomemeasurewaspercentage of flap revascularization 5 days after pedicle ligation. Results: Rats receiving VEGF pDNA had a significantly higher rate of flap revascularization (90.8 % vs 79.8%) after pedicle ligation at 14 days (P=.045). At 8 days, rats receiving VEGF pDNA (group 1) had an increased rate of flap revascularization (58.2 % vs 42.8%) that approached significance (P=.11). Conclusion: This study demonstrates the potential of VEGF pDNA to improve revascularization and flap viability in previously irradiated tissue

Overview of medical physics education and research programs in a non-academic environment

Northwest Medical Physics Center (NMPC) is a nonprofit organization that provides clinical physics support to over 35 radiation therapy facilities concentrated in the Pacific Northwest. Although clinical service is the primary function of NMPC, the diverse array of clinical sites and physics expertise has allowed for the establishment of structured education and research programs, which are complementary to the organization\u27s clinical mission. Three clinical training programs have been developed at NMPC: a therapy medical physics residency program accredited by the Commission on Accreditation of Medical Physics Education Programs (CAMPEP), an Applied Physics Technologist (APT) program, and a summer undergraduate internship program. A partnership has also been established with a major radiation oncology clinical vendor for the purposes of validating and testing new clinical devices across multiple facilities. These programs are managed by a dedicated education and research team at NMPC, made up of four qualified medical physicists (QMPs). The education and research work has made a significant contribution to the organization\u27s clinical mission, and it has provided new training opportunities for early-career physicists across many different clinical environments. Education and research can be incorporated into nonacademic clinical environments, improving the quality of patient care, and increasing the number and type of training opportunities available for medical physicists

Case Report Lhermitte's Sign Developing after IMRT for Head and Neck Cancer

Background. Lhermitte's sign (LS) is a benign form of myelopathy with neck flexion producing an unpleasant electric-shock sensation radiating down the extremities. Although rare, it can occur after head and neck radiotherapy. Results. We report a case of Lhermitte's developing after curative intensity-modulated radiotherapy (IMRT) for a patient with locoregionally advanced oropharyngeal cancer. IMRT delivers a conformal dose of radiation in head and neck cancer resulting in a gradient of radiation dose throughout the spinal cord. Using IMRT, more dose is delivered to the anterior spinal cord than the posterior cord. Conclusions. Lhermitte's sign can develop after IMRT for head and neck cancer. We propose an anterior spinal cord structure, the spinothalamic tract to be the target of IMRT-caused LS

reconstruction from two-dimensional data

Dosimetric uncertainties of three-dimensional dos