A comprehensive evaluation of treatment accuracy, including end-to-end tests and clinical data, applied to intracranial stereotactic radiotherapy

Seravalli, Enrica; Haaren, P. M. A. van; Toorn, P.P. van der; Hurkmans, Coen

doi:10.1016/j.radonc.2015.06.004

Cited by 35 publications

(36 citation statements)

References 34 publications

(44 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also, this study focuses on setup and intrafraction uncertainties; however, there are other potential sources of error that contribute to the accuracy of GK treatment, including MRI-CT registration uncertainty, CBCT-CT registration uncertainty, and interobserver variation in target volume delineation. 18 Chung et al measured image coregistration error for frameless SRS using the GK Icon. 1 They found that the uncertainties associated with MRI-CT registration and CBCT-CT registration were less than 1 mm.…”

Section: Fig 2 Amentioning

confidence: 99%

Assessment of motion error for frame-based and noninvasive mask-based fixation using the Leksell Gamma Knife Icon radiosurgery system

Carminucci

Nie

Weiner

et al. 2018

Journal of Neurosurgery

View full text Add to dashboard Cite

T he high dose of radiation delivered via stereotactic radiosurgery (SRS) requires accurate and reproducible immobilization of the head. 7 Accuracy within a range of 1-2 mm is essential to limit irradiation of surrounding anatomical structures. A rigid stereotactic head frame has traditionally been used for fixation in Gamma Knife (GK) radiosurgery. 20 Frame-based fixation allows for precise delivery of a single high-dose fraction of radiation treatment. Motion error associated with frame-based fixation is estimated to be ≤ 1-1.5 mm. 12 New SRS strategies for the treatment of large intracranial lesions have trended toward the use of multifractionation stereotactic radiotherapy (SRT) treatments. But head frame placement is invasive, involving 4-point fixation us-ABBREVIATIONS CBCT = cone-beam computed tomography; GK = Gamma Knife; IR = infrared; LINAC = linear accelerator; SRS = stereotactic radiosurgery; SRT = stereotactic radiotherapy. OBJECTIVE The Leksell Gamma Knife Icon (GK Icon) radiosurgery system can utilize cone-beam computed tomography (CBCT) to evaluate motion error. This study compares the accuracy of frame-based and frameless mask-based fixation using the Icon system. METHODS A retrospective cohort study was conducted to evaluate patients who had undergone radiosurgery with the GK Icon system between June and December 2017. Patients were immobilized in either a stereotactic head frame or a noninvasive thermoplastic mask with stereotactic infrared (IR) camera monitoring. Setup error was defined as displacement of the skull in the stereotactic space upon setup as noted on pretreatment CBCT compared to its position in the stereotactic space defined by planning MRI for frame patients and defined as skull displacement on planning CBCT compared to its position on pretreatment CBCT for mask patients. For frame patients, the intrafractionation motion was measured by comparing pretreatment and posttreatment CBCT. For mask patients, the intrafractionation motion was evaluated by comparing pretreatment CBCT and additional CBCT obtained during the treatment. The translational and rotational errors were recorded. RESULTS Data were collected from 77 patients undergoing SRS with the GK Icon. Sixty-four patients underwent frame fixation, with pre-and posttreatment CBCT studies obtained. Thirteen patients were treated using mask fixation to deliver a total of 33 treatment fractions. Mean setup and intrafraction translational and rotation errors were small for both fixation systems, within 1 mm and 1° in all axes. Yet mask fixation demonstrated significantly larger intrafraction errors than frame fixation. Also, there was greater variability in both setup and intrafraction errors for mask fixation than for frame fixation in all translational and rotational directions. Whether the GK treatment was for metastasis or nonmetastasis did not influence motion uncertainties between the two fixation types. Additionally, monitoring IR-based intrafraction motion for mask fixation-i.e., the number of treatment stoppages due to re...

show abstract

Section: Fig 2 Amentioning

confidence: 99%

Assessment of motion error for frame-based and noninvasive mask-based fixation using the Leksell Gamma Knife Icon radiosurgery system

Carminucci

Nie

Weiner

et al. 2018

Journal of Neurosurgery

View full text Add to dashboard Cite

show abstract

“…based image guidance. Seravalli et al performed post treatmentCBCTs for 59 treatments and found an average translation magnitude of 0.6 mm 22. Badakhshi et al found an average translational intrafraction deviation of 1 mm using kV imaging with BrianLAB for 190 patients over 269 treatments 7.…”

mentioning

confidence: 99%

Optical surface guidance for submillimeter monitoring of patient position during frameless stereotactic radiotherapy

Covington

Fiveash

et al. 2019

J Applied Clin Med Phys

View full text Add to dashboard Cite

Purpose To evaluate the accuracy of monitoring intrafraction motion during stereotactic radiotherapy with the optical surface monitoring system. Prior studies showing a false increase in the magnitude of translational offsets at non‐coplanar couch positions prompted the vendor to implement software changes. This study evaluated two software improvements intended to address false offsets. Methods The vendor implemented two software improvements: a volumetric (ACO) rather than planar calibration and, approximately 6 months later, an improved calibration workflow (CIB) designed to better compensate for thermal drift. Offsets relative to the reference position, obtained at table angle 0 following image‐guided setup, were recorded before beam‐on at each table position and at the end of treatment the table returned to 0° for patients receiving SRT. Results Prior to ACO, between ACO and CIB, and after CIB, 223, 155, and 436 fractions were observed respectively. The median magnitude of translational offsets at the end of treatment was similar for all three intervals: 0.29, 0.33, and 0.27 mm. Prior to ACO, the offset magnitude for non‐zero table positions had a median of 0.79 mm and was found to increase with increasing distance from isocenter to the anterior patient surface. After ACO, the median magnitude was 0.74 mm, but the dependence on surface‐to‐isocenter distance was eliminated. After CIB, the median magnitude for non‐zero table positions was reduced to 0.57 mm. Conclusion Ongoing improvements in software and calibration procedures have decreased reporting of false offsets at non‐zero table angles. However, the median magnitude for non‐zero table angles is larger than that observed at the end of treatment, indicating that accuracy remains better when the table is not rotated.

show abstract

“…Regarding positional accuracy in radiotherapy for intracranial tumors, several studies compared the positioning accuracy of the CBCT and a floor‐mounted IGRT system . Oh et al.…”

Section: Discussionmentioning

confidence: 99%

“…In particular, high localization accuracy (typically within 1 mm) is needed in intracranial stereotactic radiotherapy (SRT) in order to not compromise the local control and to minimize the risk of intracranial complications . Several research groups reported that IGRT techniques including orthogonal kV‐imaging, oblique kV‐imaging, kV‐cone‐beam computed tomography (CBCT), and megavoltage (MV)‐CT have high accuracy for positioning verification in intracranial SRT. However, a clinical problem is presented by intracranial SRT plans that consist of a number of noncoplanar beams that cannot be achieved with the use of the above‐cited techniques.…”

Section: Introductionmentioning

confidence: 99%

Clinical commissioning of a new patient positioning system, SyncTraX FX4, for intracranial stereotactic radiotherapy

Tanabe

Umetsu²,

Sasage³

et al. 2018

J Applied Clin Med Phys

View full text Add to dashboard Cite

Background & AimsA new real‐time tracking radiotherapy (RTRT) system, the SyncTraX FX4 (Shimadzu, Kyoto, Japan), consisting of four X‐ray tubes and four ceiling‐mounted flat panel detectors (FPDs) combined with a linear accelerator, was installed at Uonuma Kikan Hospital (Niigata, Japan) for the first time worldwide. In addition to RTRT, the SyncTraX FX4 system enables bony structure‐based patient verification. Here we provide the first report of this system's clinical commissioning for intracranial stereotactic radiotherapy (SRT).Materials & MethodsA total of five tests were performed for the commissioning: evaluations of (1) the system's image quality; (2) the imaging and treatment coordinate coincidence; and (3) the localization accuracy of cone‐beam computed tomography (CBCT) and SyncTraX FX4; (4) the measurement of air kerma; (5) an end‐to‐end test.Results & DiscussionThe tests revealed the following. (1) All image quality evaluation items satisfied each acceptable criterion in all FPDs. (2) The maximum offsets among the centers were ≤0.40 mm in all combinations of the FPD and X‐ray tubes (preset). (3) The isocenter localization discrepancies between CBCT and preset #3 in the SyncTraX FX4 system were 0.29 ± 0.084 mm for anterior‐posterior, −0.19 ± 0.13 mm for superior‐inferior, 0.076 ± 0.11 mm for left‐right, −0.11 ± 0.066° for rotation, −0.14 ± 0.064° for pitch, and 0.072±0.058° for roll direction. the Pearson's product‐moment correlation coefficient between the two systems was >0.98 in all directions. (4) The mean air kerma value for preset #3 was 0.11 ± 0.0002 mGy in predefined settings (80 kV, 200 mA, 50 msec). (5) For 16 combinations of gantry and couch angles, median offset value in all presets was 0.31 mm (range 0.14–0.57 mm).ConclusionOur results demonstrate a competent performance of the SyncTraX FX4 system in terms of the localization accuracy for intracranial SRT.

show abstract

A comprehensive evaluation of treatment accuracy, including end-to-end tests and clinical data, applied to intracranial stereotactic radiotherapy

Cited by 35 publications

References 34 publications

Assessment of motion error for frame-based and noninvasive mask-based fixation using the Leksell Gamma Knife Icon radiosurgery system

Assessment of motion error for frame-based and noninvasive mask-based fixation using the Leksell Gamma Knife Icon radiosurgery system

Optical surface guidance for submillimeter monitoring of patient position during frameless stereotactic radiotherapy

Clinical commissioning of a new patient positioning system, SyncTraX FX4, for intracranial stereotactic radiotherapy

Contact Info

Product

Resources

About