Intrafractional motion and interfractional changes affect the accuracy of the delivered dose in radiotherapy, particularly in charged-particle radiotherapy. Most recent studies are focused on intrafractional motion (respiratory motion). Here, we report a quantitative simulation analysis of the effects of interfractional changes on water-equivalent pathlength (WEL) in charged-particle lung thera...

We quantified dose variation effects due to respiratory-induced intrafractional motion in conventional carbon-ion prostate treatment by using four-dimensional computed tomography (4DCT). 4DCT scans of 20 patients were acquired under free-breathing conditions using a 256 multi-slice CT scanner. The clinical target volume (CTV) was defined as the prostate and the seminal vesicle. Two types of pla...

Abstract Proton therapy treatment for lungs remains challenging as images enabling the detection of inter- and intra-fractional motion, which could be used proton dose adaptation, are not readily available. 4D computed tomography (4DCT) provides high image quality but is rarely available in-room, while in-room cone beam (4DCBCT) suffers from limitations stemming mostly scatter detection. This s...

Electrical impedance tomography (EIT) is a promising imaging technique for bedside monitoring of lung function. It is easily applicable, cheap and requires no ionizing radiation, but clinical interpretation of EIT-images is still not standardized. One of the reasons for this is the ill-posed nature of EIT, allowing a range of possible images to be produced-rather than a single explicit solution...

It is well known that significant variations in stomach size, shape, and respiratory motion lead to uncertainties in target localization during treatment for gastric lymphoma. In this study, the usefulness of 4D-CT for radiation planning of gastric MZBCL/MALT was evaluated. Treatment planning using 4DCT (plan A) and conventional planning with a uniform margin (plan B) were compared using dose v...

The major problem with ventilation distribution calculations using DIR and 4DCT is the motion artifacts in 4DCT. Quite often not all phases would exhibit mushroom motion artifacts. If the ventilation series similarity is sufficiently robust, the ventilation distribution can be calculated using only the artifact-free phases. This study investigated the ventilation similarity among the data deriv...

Surrogate-driven respiratory motion models relate the motion of the internal anatomy to easily acquired respiratory surrogate signals, such as the motion of the skin surface. They are usually built by first using image registration to determine the motion from a number of dynamic images, and then fitting a correspondence model relating the motion to the surrogate signals. In this paper we prese...

Current radiation therapy (RT) planning for limiting lung toxicity assumes a uniform distribution of lung function with little consideration to the spatial and temporal pattern of lung function. Establishment of relationships between radiation dose and pulmonary function change can help predict and reduce the RT-induced pulmonary toxicity. Baseline measurement uncertainty of pulmonary function ...