Comparison of Kilovoltage Cone-Beam Computed Tomography With Megavoltage Projection Pairs for Paraspinal Radiosurgery Patient Alignment and Position Verification

Kriminski, S; Lovelock, D. Michael; Seshan, Venkatraman; Ali, I; Munro, Peter; Amols, Howard; Fuks, Zvi; Bilsky, Mark H.; Yamada, Yoshiya

doi:10.1016/j.ijrobp.2008.04.029

Cited by 15 publications

(18 citation statements)

References 14 publications

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“…The number of treatments given using in-room CT, pairs of MV localization images and implanted markers, and cone-beam localization were 1, 55, and 35, respectively. The systematic uncertainties of MV and cone-beam–guided setups in our clinic have been studied and found to be on the of order 1.0 mm and 0.3 mm, respectively (18). The random uncertainties of registration of the markers implanted into the spine using MV images was found to be 0.5 mm ± 0.5 mm.…”

Section: Methodsmentioning

confidence: 99%

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Correlation of Local Failure With Measures of Dose Insufficiency in the High-Dose Single-Fraction Treatment of Bony Metastases

Lovelock

Zhang

Jackson

et al. 2010

International Journal of Radiation Oncology*Biology*Physics

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Purpose In the setting of high-dose single-fraction image-guided radiotherapy of spine metastases, the delivered dose is hypothesized to be a significant factor in local control. We investigated the dependence of local control on measures of dose insufficiency. Methods and Materials The minimum doses received by the hottest 100%, 98%, and 95% (Dmin, D98, and D95) of the gross target volume (GTV) were computed for 91 consecutively treated lesions observed in 79 patients. Prescribed doses of 18–24 Gy were delivered in a single fraction. The spinal cord and cauda equina were constrained to a maximum dose of 12–14 Gy and 16 Gy, respectively. A rank-sum test was used to assess the differences between radiographic local failure and local control. Results With a median follow-up of 18 months, seven local failures have occurred. The distributions of GTV Dmin, D98, and D95 for treatments resulting in local failure were found to be statistically different from the corresponding distributions of the patient group as a whole. Taking no account of histology, p values calculated for Dmin, D98, and D95 were 0.004, 0.012, and 0.031, respectively. No correlations between local failure and target volume or between local failure and anatomic location were found. Conclusions The results indicate that Dmin, D98, and D95 may be important risk factors for local failure. No local failures in any histology were observed when Dmin was >15 Gy, suggesting that this metric may be an important predictor of local control.

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Section: Methodsmentioning

confidence: 99%

“…The random uncertainties of the cone-beam CT registration were found to be less than or equal to those of the MV technique. In consequence, the combined overall uncertainty in target positioning is estimated to be less than 2 mm for both techniques (18). …”

Section: Methodsmentioning

confidence: 99%

Correlation of Local Failure With Measures of Dose Insufficiency in the High-Dose Single-Fraction Treatment of Bony Metastases

Lovelock

Zhang

Jackson

et al. 2010

International Journal of Radiation Oncology*Biology*Physics

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“…The IGRT systems can be broken down into those based on stereoscopic xray-and CT-based imaging. For spine SBRT, the target can be positioned accurately to within 1-2 mm and 1°-2° with either IGRT system, 9,22,25,27,34 but there are inherent differences between the two that require discussion.…”

Section: Guidance With Ct-based or Stereoscopic X-ray Imaging To Verimentioning

confidence: 99%

Stereotactic body radiotherapy for spinal metastases: current status, with a focus on its application in the postoperative patient

Sahgal

Bilsky

Chang³

et al. 2011

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Stereotactic body radiotherapy (SBRT) for spinal metastases is an emerging therapeutic option aimed at delivering high biologically effective doses to metastases while sparing the adjacent normal tissues. This technique has emerged following advances in radiation delivery that include sophisticated radiation treatment planning software, body immobilization devices, and capabilities of detecting and correcting patient positional deviations with imageguided radiotherapy. There are limited clinical data specifically supporting the role of SBRT as a superior alternative to conventional radiation in the postoperative patient. The focus of this review was to examine the evidence pertaining to spine SBRT in the treatment of spinal metastases and to provide a comprehensive analysis of published patterns of failure, with emphasis on the postoperative patient.

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“…The RC-CBCT scan uses a kilovoltage x-ray imaging system (On-Board Imaging, Varian Medical Systems), which has been described in detail in Ref. 21.…”

Section: Methodsmentioning

confidence: 99%

A study of respiration‐correlated cone‐beam CT scans to correct target positioning errors in radiotherapy of thoracic cancer

et al. 2012

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Purpose: There is increasingly widespread usage of cone-beam CT (CBCT) for guiding radiation treatment in advanced-stage lung tumors, but difficulties associated with daily CBCT in conventionally fractionated treatments include imaging dose to the patient, increased workload and longer treatment times. Respiration-correlated cone-beam CT (RC-CBCT) can improve localization accuracy in mobile lung tumors, but further increases the time and workload for conventionally fractionated treatments. This study investigates whether RC-CBCT-guided correction of systematic tumor deviations in standard fractionated lung tumor radiation treatments is more effective than 2D imagebased correction of skeletal deviations alone. A second study goal compares respiration-correlated vs respiration-averaged images for determining tumor deviations. Methods: Eleven stage II-IV nonsmall cell lung cancer patients are enrolled in an IRB-approved prospective off-line protocol using RC-CBCT guidance to correct for systematic errors in GTV position. Patients receive a respiration-correlated planning CT (RCCT) at simulation, daily kilovoltage RC-CBCT scans during the first week of treatment and weekly scans thereafter. Four types of correction methods are compared: (1) systematic error in gross tumor volume (GTV) position, (2) systematic error in skeletal anatomy, (3) daily skeletal corrections, and (4) weekly skeletal corrections. The comparison is in terms of weighted average of the residual GTV deviations measured from the RC-CBCT scans and representing the estimated residual deviation over the treatment course. In the second study goal, GTV deviations computed from matching RCCT and RC-CBCT are compared to deviations computed from matching respiration-averaged images consisting of a CBCT reconstructed using all projections and an average-intensity-projection CT computed from the RCCT. Results: Of the eleven patients in the GTV-based systematic correction protocol, two required no correction, seven required a single correction, one required two corrections, and one required three corrections. Mean residual GTV deviation (3D distance) following GTV-based systematic correction (mean ± 1 standard deviation 4.8 ± 1.5 mm) is significantly lower than for systematic skeletal-based (6.5 ± 2.9 mm, p = 0.015), and weekly skeletal-based correction (7.2 ± 3.0 mm, p = 0.001), but is not significantly lower than daily skeletal-based correction (5.4 ± 2.6 mm, p = 0.34). In two cases, first-day CBCT images reveal tumor changes-one showing tumor growth, the other showing large tumor displacement-that are not readily observed in radiographs. Differences in computed GTV deviations between respiration-correlated and respiration-averaged images are 0.2 ± 1.8 mm in the superior-inferior direction and are of similar magnitude in the other directions. Conclusions: An off-line protocol to correct GTV-based systematic error in locally advanced lung tumor cases can be effective at reducing tumor deviations, although the findings need confirmation with larger patient s...

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Comparison of Kilovoltage Cone-Beam Computed Tomography With Megavoltage Projection Pairs for Paraspinal Radiosurgery Patient Alignment and Position Verification

Cited by 15 publications

References 14 publications

Correlation of Local Failure With Measures of Dose Insufficiency in the High-Dose Single-Fraction Treatment of Bony Metastases

Correlation of Local Failure With Measures of Dose Insufficiency in the High-Dose Single-Fraction Treatment of Bony Metastases

Stereotactic body radiotherapy for spinal metastases: current status, with a focus on its application in the postoperative patient

A study of respiration‐correlated cone‐beam CT scans to correct target positioning errors in radiotherapy of thoracic cancer

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