OC-0332: Kilovoltage intrafraction motion monitoring and target dose reconstruction for liver SBRT delivered by VMAT

Ultrasound for intrafraction motion monitoring

Experimentally studied dynamic dose interplay does not meaningfully affect target dose in VMAT SBRT lung treatments.

PURPOSE The effects of respiratory motion on the tumor dose can be divided into the gradient and interplay effects. While the interplay effect is likely to average out over a large number of fractions, it may play a role in hypofractionated [stereotactic body radiation therapy (SBRT)] treatments. This subject has been extensively studied for intensity modulated radiation therapy but less so for...

Viability of Noncoplanar VMAT for liver SBRT compared with coplanar VMAT and beam orientation optimized 4π IMRT

PURPOSE The 4π static non-coplanar radiotherapy delivery technique has demonstrated better normal tissue sparing and dose conformity than the clinically used volumetric modulated arc therapy (VMAT). It is unclear whether this is a fundamental limitation of VMAT delivery or the coplanar nature of its typical clinical plans. The dosimetry and the limits of normal tissue toxicity constrained dose ...

Predicting liver SBRT eligibility and plan quality for VMAT and 4π plans

BACKGROUND It is useful to predict planned dosimetry and determine the eligibility of a liver cancer patient for SBRT treatment using knowledge based planning (KBP). We compare the predictive accuracy using the overlap volume histogram (OVH) and statistical voxel dose learning (SVDL) KBP prediction models for coplanar VMAT to non-coplanar 4π radiotherapy plans. METHODS In this study, 21 liver...

Computer simulations concerning influence of target motion on dose distribution delivered by the GSI raster scanner

Target motion is a very big problem in conformal radiotherapy (CRT), especiallly for a charged particle beam because of its less lateral scattering and sharp Bragg peak. In the pilot project of the heavy-ion cancer therapy at GSI, patients with head and neck tumors are treated with a magnetic raster scanner[1]. However, if the raster scanner is used to treat patients with body tumors, motion of...