BACKGROUND Accurate puncture during percutaneous transforaminal endoscopic discectomy at the L5/S1 level in cases with high iliac crest and narrow foramen were difficult, even though the difficulties of foraminoplasty could be overcome by advanced instruments like reamers. OBJECTIVES The report aimed to describe an isocentric navigation technique with a definite pathway in difficult puncture ...

A case study based on both simulated and actual images was performed. The simulated anatomical phantom used was obtained from CT data of a human leg provided by the “Visible Human” project. A virtual orthopedic nail was added to the data set and projection images were obtained using a simulated irradiation procedure. An actual phantom made of wax having an orthopedic nail inserted was also imag...

The accurate measurement of the linear accelerator (linac) radiation isocenter is critical, especially for stereotactic treatment. Traditional quality assurance (QA) procedure focuses on the measurement of single radiation isocenter, usually of 6 megavoltage (MV) photon beams. Single radiation isocenter is also commonly assumed in treatment planning systems (TPS). Due to different flattening fi...

Purpose: Evaluation of the newly integrated system for its validation and designing a quality assurance frame work to assess its geometrical, radiological and mechanical accuracy. Methods: Isocentric accuracy of two independent imaging modalities, kV based ExacTrac and MV based iViewGT was evaluated using Winston-Lutz test. A pelvic humanoid phantom was used for the radiological end-to-end test...

A reversed-phase gradient elution, UV detection method is developed for the simultaneous determination of mono (2-ethylhexyl) phthalate [MEHP] and di (2-ethylhexyl) phthalate [DEHP] in tissue samples. The method is validated with respect to extraction recovery, inter and intra-day precision, linearity of response, detect ability, and specificity. The validated method has been successfully appli...

An extendable x-ray multi-leaf collimator (eMLC) is investigated for collimation of electron beams on a linear accelerator. The conventional method of collimation using an electron applicator is impractical for conformal, modulated and mixed beam therapy techniques. An eMLC would allow faster, more complex treatments with potential for reduction in dose to organs-at-risk and critical structures...

We present a technique--based on the Lutz, Winston, and Maleki test used in stereotactic linear accelerator radiosurgery--for verifying whether proton beams are being delivered within the required spatial coincidence with the gantry mechanical isocenter. Our procedure uses a proton beam that is collimated by a circular aperture at its central axis and is then intercepted by a small steel sphere...