Synchronized moving aperture radiation therapy (SMART): average tumour trajectory for lung patients

Neicu, T; Shirato, Hiroki; Seppenwoolde, Yvette; Jiang, Steve B

doi:10.1088/0031-9155/48/5/303

Cited by 207 publications

(163 citation statements)

References 23 publications

Supporting

Mentioning

163

Contrasting

Order By: Relevance

“…The period of oscillation of the platform was set to approximately 4 s to model typical patient breathing. ( 17 – 19 ) For the irradiation, we placed a NOMOS IMRT QA phantom on the platform. Kodak EDR2 film was placed within the phantom in an axial orientation using a 3D square to ensure reproducible alignment (see Fig.…”

Section: Methodsmentioning

confidence: 99%

Measurement of the interplay effect in lung IMRT treatment using EDR2 films

Berbeco

Pope

Jiang

2006

J Applied Clin Med Phys

View full text Add to dashboard Cite

Intrafraction organ motion during the dynamic delivery of intensity‐modulated radiation therapy (IMRT) treatment of lung tumors may cause unexpected hot/cold spots within the target volume, due to the interplay effect between tumor motion and multileaf collimator (MLC) leaf motion. In the past, this has been investigated through theoretical analysis, computer simulation, and experimental measurement using an ionization chamber dosimeter. In the work presented here, the interplay effect was studied experimentally in 2D, using Kodak EDR2 films. A five‐field lung IMRT plan was delivered to a solid water phantom with embedded film. The phantom was placed on a motor‐driven platform with a sinusoidal motion to simulate the respiration‐induced tumor motion. The delivery of each field began at one of eight equally spaced initial breathing phases. The dose distribution for each treatment fraction was estimated by combining the dose distributions for all fields with randomly sampled initial breathing phases. The dose variation caused by the interplay effect was estimated by looking at the dose values from 1000 trials of 30 fractions. It was found that, on a day‐to‐day basis, the standard deviation of the dose to a given pixel in the high‐dose region could be as high as 2% to 4% due to the motion interplay effect. After 30 fractions, the standard deviation in the dose to each pixel is reduced to 0.4% to 0.7%. However, compared to the static delivery, the dose distribution from a 30‐fraction case in the presence of motion shows some underdosing in the region of interest. We found that the maximum dose in the target remains within 1% of the maximum dose in the static case, but the minimum dose in the target is most likely to be about 6% lower than the static case. Our results indicate that there can be some underdosing of the tumor due to the interplay effect in lung IMRT delivery over the entire course of a 30‐fraction treatment.PACS number: 87.53.Mr

show abstract

Section: Methodsmentioning

confidence: 99%

Measurement of the interplay effect in lung IMRT treatment using EDR2 films

Berbeco

Pope

Jiang

2006

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…Four-dimensional ͑4D͒ radiotherapy by target tracking 15,16 is a newly developed motion mitigation technique. In this technique, dynamic MLC leaf motions are adjusted to track the target motion.…”

Section: Helical Tomotherapymentioning

confidence: 99%

Treatment plan optimization incorporating respiratory motion

et al. 2004

View full text Add to dashboard Cite

Similar to conventional conformal radiotherapy, during lung tomotherapy, a motion margin has to be set for respiratory motion. Consequently, large volume of normal tissue is irradiated by intensive radiation. To solve this problem, we have developed a new motion mitigation method by incorporating target motion into treatment optimization. In this method, the delivery-breathing correlation is determined prior to treatment plan optimization. Beamlets are calculated by using the CT images at the corresponding breathing phases from a dynamic ͑four-dimensional͒ image sequence. With the displacement vector fields at different breathing phases, a set of deformed beamlets is obtained by mapping the dose to the primary phase. Optimization incorporating motion is then performed by using the deformed beamlets obtained by dose mapping. During treatment delivery, the same breathing-delivery correlation can be reproduced by instructing the patient to breathe following a visually displayed guiding cycle. This method was tested using a computer-simulated deformable phantom and a real lung case. Results show that treatment optimization incorporating motion achieved similar high dose conformality on a mobile target compared with static delivery. The residual motion effects due to imperfect breathing tracking were also analyzed.

show abstract

“…For intrafractional motion compensation, modelling of breathing motion [16][17][18] is a topical field of research. Here, a typical patient-specific motion pattern is applied to simulate the motion of the tumor target volume (usually the lung or the liver) during irradiation.…”

Section: Introductionmentioning

confidence: 99%

High-performance GPU-based rendering for real-time, rigid 2D/3D-image registration and motion prediction in radiation oncology

Spoerk

Gendrin

Weber

et al. 2012

Zeitschrift für Medizinische Physik

View full text Add to dashboard Cite

A common problem in image-guided radiation therapy (IGRT) of lung cancer as well as other malignant diseases is the compensation of periodic and aperiodic motion during dose delivery. Modern systems for image-guided radiation oncology allow for the acquisition of cone-beam computed tomography data in the treatment room as well as the acquisition of planar radiographs during the treatment. A mid-term research goal is the compensation of tumor target volume motion by 2D/3D registration. In 2D/3D registration, spatial information on organ location is derived by an iterative comparison of perspective volume renderings, so-called digitally rendered radiographs (DRR) from computed tomography volume data, and planar reference x-rays. Currently, this rendering process is very time consuming, and real-time registration, which should at least provide data on organ position in less than a second, has not come into existence. We present two GPU-based rendering algorithms which generate a DRR of 512 × 512 pixels size from a CT dataset of 53 MB size at a pace of almost 100 Hz. This rendering rate is feasible by applying a number of algorithmic simplifications which range from alternative volume-driven rendering approaches -namely so-called wobbled splatting -to sub-sampling of the DRR-image by means of specialized raycasting techniques. Furthermore, general purpose graphics processing unit (GPGPU) programming paradigms were consequently utilized. Rendering quality and performance as well as the influence on the quality and performance of the overall registration process were measured and analyzed in detail. The results show that both methods are competitive and pave the way for fast motion compensation by rigid and possibly even non-rigid 2D/3D registration and, beyond that, adaptive filtering of motion models in IGRT.

show abstract

Synchronized moving aperture radiation therapy (SMART): average tumour trajectory for lung patients

Cited by 207 publications

References 23 publications

Measurement of the interplay effect in lung IMRT treatment using EDR2 films

Measurement of the interplay effect in lung IMRT treatment using EDR2 films

Treatment plan optimization incorporating respiratory motion

High-performance GPU-based rendering for real-time, rigid 2D/3D-image registration and motion prediction in radiation oncology

Contact Info

Product

Resources

About