The aim of this study is to determine whether stereotactic body radiotherapy for multiple vertebral metastases treated with a single isocenter results in greater intrafraction errors than stereotactic body radiotherapy for single vertebral metastases and to determine whether the currently used spinal cord planning organ at risk volume and planning target volume margins are appropriate. Intrafra...

Introduction: Presence of dental filling material (DFM) such as amalgam in treatment patient with nasopharyngeal cancer (NPC) is common. Streaking artifact Arising from this high density material in computed tomography (scan), may lead to perturbation in dose calculation and dose delivery. Widespread performance of intensity-modulated radiotherapy (IMRT) for NPC using anterior...

Background: In Helical Tomotherapy (HT), the scaling factor (SF) is the time in seconds that each leaf viewing a target would need to be open to deliver the prescribed dose. The SF is patient-specific and is used to calculate the rotational period of the gantry, and the total treatment time (TTT) of the HT. The SF is generally difficult to estimate. Currently, it takes about one hour t...

When the planning target volume (PTV), extends close to or beyond the skin, inverse-planned intensity-modulated radiotherapy can boost the fluence from tan- gential angles to superficial parts of the PTV due to the buildup effect. This can result in significant regions of high dose upon a small movement in the patient's position. We analyzed different methods of reducing this effect in the Tomo...

BACKGROUND The purpose of this study is to investigate the potential to reduce exposure of the contralateral hippocampus in radiotherapy for glioblastoma using volumetric modulated arc therapy (VMAT). METHODS Datasets of 27 patients who had received 3D conformal radiotherapy (3D-CRT) for glioblastoma with a prescribed dose of 60Gy in fractions of 2Gy were included in this planning study. VMAT...

INTRODUCTION Several single institution phase I and phase II trials of stereotactic ablative body radiotherapy (SABR) for liver tumors have reported promising results and high local control rates of over 90%. However, there are wide variations in dose and fractionation due to different prescription policies and treatment methods across SABR series that have been published to date.This study aim...

Advances in magnetic resonance imaging (MRI) sequences allow physicians to define the dominant intraprostatic lesion (IPL) in prostate radiation therapy treat-ments allowing for dose escalation and potentially increased tumor control. This work quantifies the margin required around the MRI-defined IPL accounting for both prostate motion and deformation. Ten patients treated with a simultaneous ...

INTRODUCTION This study compared four different volumetric modulated arc therapy (VMAT) beam arrangements for the treatment of early-stage prostate cancer examining plan quality and the impact on a radiotherapy department's resources. METHODS Twenty prostate cases were retrospectively planned using four VMAT beam arrangements (1) a partial arc (PA), (2) one arc (1A), (3) one arc plus a partia...

Malignant pleural mesothelioma (MPM) is an extremely difficult disease to treat. This pilot study investigates the feasibility of using volumetric-modulated arc therapy (VMAT) for malignant pleural mesothelioma (MPM), and compares VMAT to static field intensity-modulated radiotherapy (IMRT) for five patients. To identify the best treatment technique for MPM, in five patients, we made a represen...

PURPOSE To study the impacts of multileaf collimators (MLC) width [standard MLC width of 10 mm (sMLC) and micro-MLC width of 4 mm (mMLC)] in the intensity-modulated radiotherapy (IMRT) planning for the upper thoracic esophageal cancer (UTEC). METHODS AND MATERIALS 10 patients with UTEC were retrospectively planned with the sMLC and the mMLC. The monitor unites (MUs) and dose volume histogram-...