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We propose a clinical workflow of stereotactic volumetric modulated arc therapy (VMAT) for a lung tumor from planning to tumor position verification using 4D planning computed tomography (CT) and 4D cone-beam CT (CBCT). A 4D CT scanner, an Anzai belt and a BodyFix were employed to obtain 10-phase respiratory-correlated CT data for a lung patient under(More)
We have successfully created a single arc volumetric modulated arc therapy (VMAT) plan for treating post-surgical left breast/chest wall and regional nodes using Elekta multileaf collimator (MLC). Dose volume histograms (DVHs) were compared between the VMAT plans and conventional tangential beam plans using a field-in-field technique, leading to significant(More)
We have proposed four dimensional (4D) digitally reconstructed radiography (DRR) for verifying a lung tumor position during volumetric modulated arc therapy (VMAT). An internal target volume (ITV) was defined based on two clinical target volumes (CTVs) delineated on maximum exhalation and maximum inhalation images acquired by 4D planning computed tomography(More)
Localization and verification of a tumor position was conventionally performed prior to radiotherapy. The present authors, in the past a few years, proposed in-treatment verification of the tumor position by simultaneously acquiring cone beam computed tomography (CBCT) data using an on-board kilovolt imaging system. Dose delivery was either rotational(More)
A compensator made of a tungsten-based rod matrix has been proposed for small-field intensity modulated radiation therapy. The compensator was attached to a 6 MV linac gantry head. The proposed compensator could modulate the X-ray intensity with a step of 10% and a minimum transmission of 2.5%.
To the Editor, Volumetric modulated arc therapy (VMAT) serves as a means for stereotactic hypofractionated treatment of lung tumors [1]. The present authors proposed an efficient VMAT sequence by restricting leaf speeds of a multi-leaf collimator per gantry rotation angle to below 1 mm/degree, thereby reducing the dose delivery time down to 210 s for a D95(More)
Time-averaged intreatment prostate localization errors were calculated, for the first time, by three-dimensional prostate image cross-correlation between planning CT and intrafraction kilovoltage cone-beam CT (CBCT) during volumetric modulated arc therapy (VMAT). The intrafraction CBCT volume was reconstructed by an inhouse software after acquiring(More)
The feasibility of single isocenter, multi-arc non-coplanar volumetric modulated arc therapy (VMAT) for multiple brain tumors was studied using an Elekta Synergy linear accelerator with an Agility multileaf collimator and a Monaco treatment planning system. Two VMAT radiosurgery plans consisting of a full arc and three half arcs were created with a(More)
Dear Editor, Several different approaches have been applied to stereo-tactic hypofractionated radiotherapy for lung tumors, including free breathing, breath-hold, gating, and tracking. Negoro et al. reported that abdominal compression reduced the movement of lung tumors (thereby possibly reducing treatment uncertainty), with portal fluoroscopy being used to(More)
High-atomic number materials such as those used in making artificial bones or prostheses, spinal cord fixation devices and dental fillings may be located in patients undergoing radiotherapy. These devices may have a major influence on absorbed dose distributions in the body, as they cause significant beam attenuation and scattering. A report of the American(More)