Biofidelic image registration for head and neck region utilizing an in-silico articulated skeleton as a transformation model.

We propose an integration scheme for a biomechanical motion model into a deformable image registration. We demonstrate its accuracy and reproducibility for adaptive radiation therapy in the head and neck region..

Analyzing human decisions in IGRT of head-and-neck cancer patients to teach image registration algorithms what experts know.

Background: In IGRT of deformable head-and-neck anatomy, patient setup corrections are derived by rigid registration methods. In practice, experienced radiation therapists often correct the resulting vectors, thus indicating a different prioritization of alignment of local structures. Purpose of this study is to transfer the knowledge experts apply when correcting the automatically generated result (pre-match) to automated registration.

Construction of a biomechanical head and neck motion model as a guide to evaluation of deformable image registration.

The use of deformable image registration methods in the context of adaptive radiotherapy leads to uncertainties in the simulation of the administered dose distributions during the treatment course. Evaluation of these methods is a prerequisite to decide if a plan adaptation will improve the individual treatment. Current approaches using manual references limit the validity of evaluation, especially for low-contrast regions.

Real-time markerless lung tumor tracking in fluoroscopic video: Handling overlapping of projected structures.

Purpose: Fluoroscopic imaging is a well-suited technique for online visualization of tumor motion in the thoracic region. Template-based approaches for tumor tracking in such images are commonly used. However, overlapping of different structures, mainly bones, can lead to limited visibility of the projected tumor shape, which in turn can negatively affect the performance of the tracking method.

[Percutaneous ultrasonic-guided nephropyelostomy in tumor-caused block of urinary outflow].

A report is given on the method and results of ultrasound-guided nephropyelostomy which has been performed here for several years without open surgical intervention. The method has a low rate of complications and can be applied in severely ill patients, too. The problems of ureteral obstruction are quickly eliminated, even if the tumor has not been removed by chemotherapy, radiotherapy, or surgery.