The purpose of this study is to develop a fast and convergence proofed CBCT reconstruction framework based on the compressed sensing theory which not only lowers the imaging dose but also is computationally practicable in the busy clinic. We simplified the original mathematical formulation of gradient projection for sparse reconstruction (GPSR) to minimize the number of forward and backward pro...

The use of image-guided patient positioning requires fast and reliable Quality Assurance (QA) methods to ensure the megavoltage (MV) treatment beam coincides with the integrated kilovoltage (kV) or volumetric cone-beam CT (CBCT) imaging and guidance systems. Current QA protocol is based on visually observing deviations of certain features in acquired kV in-room treatment images such as markers,...

The use of image-guidance in surgery and radiotherapy has significantly improved patient outcome in neurosurgery and radiotherapy treatments. This work developed volume definition and verification techniques for image-guided applications, using a number of algorithms ranging from image processing to visualization. Stereoscopic visualization, volumetric tumor model overlaid on an ultrasound imag...

BACKGROUND The purpose of this study was to determine the feasibility of nondaily image-guided radiotherapy (RT) strategies with intensity-modulated radiotherapy (IMRT) for head and neck cancer. METHODS Alignment data was analyzed from 103 consecutive patients treated by IMRT for head and neck cancer who had undergone daily imaging with onboard mega-voltage CT (MVCT), resulting in 3275 images...

In the last decades the status of radiotherapy was tremendously increased in terms of conformity to the target as well as image-guided techniques in conjunction with intensity-modulated radiotherapy (IMRT). The technological improvement had a significant clinical outcome for better response and lower toxicity to the surrounding normal tissues. Nowadays the incidence of rectal toxicity has been ...

Sectional imaging is integrated in each link of the modern radiotherapy chain, from diagnostic procedures to target volume definition to treatment planning, dose delivery, and verification. While CT is widely used for modern EBRT, including intensity modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT), MRI represents the gold standard for IGBT for gynecological malignancies (see ...

BACKGROUND This pilot trial is designed to determine whether PET/CT-guided radiotherapy dose escalation can improve local control while minimizing toxicity for the treatment of locally advanced nasopharyngeal carcinoma. METHODS 67 patients were randomized into the three treatment arms: conventional chemoradiotherapy (group A), CT-guided dose escalation chemoradiotherapy (group B) and PET/CT-g...

The sharp dose gradients in intensity-modulated radiation therapy increase the treatment sensitivity to various interand intra-fractional uncertainties, in which a slight anatomical change may greatly alter the actual dose delivered. Image-guided radiotherapy refers to the use of advanced imaging techniques to precisely track and correct these patient-specific variations in routine treatment. I...

Radiation therapy has come a long way from treatment planning based on orthogonal radiographs with large margins around tumours. Advances in imaging and radiation planning software have led to three-dimensional conformal radiotherapy and, further, to intensity modulated radiotherapy (IMRT). IMRT permits sparing of normal tissues and hence dose-escalation to tumours. IMRT is the current standard...