Prediction of Intrafraction Prostate Motion: Accuracy of Pre- and Post-Treatment Imaging and Intermittent Imaging

Noël, C.; Parikh, Parag J.; Roy, M.; Kupelian, Patrick A.; Mahadevan, A.; Weinstein, G.; Enke, Charles Arthur; Flores, N.; Beyer, David; Levine, L.

doi:10.1016/j.ijrobp.2008.04.076

Cited by 56 publications

(44 citation statements)

References 30 publications

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“…Because it has been long believed that prostate motion and setup errors are random, Gaussian approximation is considered to be good without loss of generality, especially after multiple fractions based on the central limit theorem (2,10). To evaluate the validity of the Gaussian approximation assumption, the prostate motion was characterized using real-time tracking data during radiation treatment.…”

Section: Prostate Motion Distribution Analysis: Individual Fractionmentioning

confidence: 99%

The Non-Gaussian Nature of Prostate Motion Based on Real-Time Intrafraction Tracking

Lin

Liu

Yang

et al. 2013

International Journal of Radiation Oncology*Biology*Physics

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Purpose-The objective of this work is to test the validity of the Gaussian approximation for prostate motion through characterization of its spatial distribution.Methods and Materials-Real-time intrafraction prostate motion was observed using Calypso 4-dimensional (4D) nonradioactive electromagnetic tracking system. We report the results from a total of 1024 fractions from 31 prostate cancer patients. First, the correlation of prostate motion in right/left (RL), anteroposterior (AP), and superoinferior (SI) direction were determined using Pearson's correlation of coefficient. Then the spatial distribution of prostate motion was analyzed for individual fraction, individual patient including all fractions, and all patients including all fractions. The displacement in RL, AP, SI, oblique, or total direction is fitted into a Gaussian distribution, and a Lilliefors test was used to evaluate the validity of the hypothesis that the displacement is normally distributed.Results-There is high correlation in AP/SI direction (61% of fractions with medium or strong correlation). This is consistent with the longitudinal oblique motion of the prostate, and likely the effect from respiration on an organ confined within the genitourinary diaphragm with the rectum sitting posteriorly and bladder sitting superiorly. In all directions, the non-Gaussian distribution is more common for individual fraction, individual patient including all fractions, and all patients including all fractions. The spatial distribution of prostate motion shows an elongated shape in oblique direction, indicating a higher range of motion in the AP and SI directions.Conclusions-Our results showed that the prostate motion is highly correlated in AP and SI direction, indicating an oblique motion preference. In addition, the spatial distribution of prostate motion is elongated in an oblique direction, indicating that the organ motion dosimetric modeling

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Section: Prostate Motion Distribution Analysis: Individual Fractionmentioning

confidence: 99%

The Non-Gaussian Nature of Prostate Motion Based on Real-Time Intrafraction Tracking

Lin

Liu

Yang

et al. 2013

International Journal of Radiation Oncology*Biology*Physics

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“…As pointed out elsewhere [22], the number and location of prostate surrogates and differences in observation time can explain in part the variation among published prostate intrafraction motion measurements. The findings of Noel et al [27] support the value of continuous, real-time tracking to reduce the uncertainty caused by prostate motion during the delivery of radiation. Such a tracking procedure would result in substantially reduced margins, however, is difficult to realize in clinical practice.…”

Section: Discussionmentioning

confidence: 78%

“…In particular, Bod-Heggemann et al [4] and Kotte et al [17] found overall displacements of 0.6-0.9 mm ± 0.9-1.7 mm during fraction times of 7-15 min. Other investigators observed larger intrafractional prostate displacements of > 5 mm in only 8-15% of fractions measured by cone-beam CT [29] or electromagnetic tracking [27]. During online tracking, the percentage appears to increase with the sampling rate, i.e., fast motions are existent.…”

Section: Discussionmentioning

confidence: 94%

Residual Translational and Rotational Errors after kV X-Ray Image-Guided Correction of Prostate Location Using Implanted Fiducials

et al. 2010

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“…Recent studies analyzed pre‐ and post‐treatment CBCT ( 3 – 5 ) for evaluation of intrafractional motion during intensity‐modulated RT (IMRT) with a fixed gantry.…”

Section: Introductionmentioning

confidence: 99%

Cone beam CT pre‐ and post‐daily treatment for assessing geometrical and dosimetric intrafraction variability during radiotherapy of prostate cancer

Reggiori

Mancosu

Tozzi

et al. 2010

J Applied Clin Med Phys

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The purpose of this study was to quantify the relationship between treatment time and dose uncertainty due to intrafraction organ motion in prostate cancer radiotherapy (RT). Ten consecutive patients with prostate cancer treated by radical RT by volumetric modulated arc therapy (RapidArc) were considered. For each patient, pre‐ and post‐treatment cone beam computed tomography (CBCT) was performed in 10 fractions. The prostate, rectum and bladder were contoured on each CBCT. The change in organ position, volume and dosimetric uncertainty induced by organ motion were evaluated. Interval time between the two CBCTs ranged between 4 and 16 min (mean 7.3±0.7 min). Treatment with intrafraction prostate motion > 3 mm and > 5 mm were 24% and 5%, respectively. Regarding change in centroid position and volume, a poor time correlation was found for target and rectum, while a constant increase was obtained for bladder. The agreement index was highly correlated to time (normalr=−0.89 for bladder, normalr=−0.95 for rectum, and normalr=−0.84 for prostate). In terms of difference in dose volume histogram between pre‐ and post‐CBCT, the dose uncertainties for the targets and rectum amplified with the increasing time. The increasing intrafraction dose uncertainty with time requires the use of an RT technique with minimization of treatment time to improve confidence in planning dose distribution.PACS number: 87.55.tm

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Prediction of Intrafraction Prostate Motion: Accuracy of Pre- and Post-Treatment Imaging and Intermittent Imaging

Cited by 56 publications

References 30 publications

The Non-Gaussian Nature of Prostate Motion Based on Real-Time Intrafraction Tracking

The Non-Gaussian Nature of Prostate Motion Based on Real-Time Intrafraction Tracking

Residual Translational and Rotational Errors after kV X-Ray Image-Guided Correction of Prostate Location Using Implanted Fiducials

Cone beam CT pre‐ and post‐daily treatment for assessing geometrical and dosimetric intrafraction variability during radiotherapy of prostate cancer

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