The use of six degrees of freedom couch is only clinically beneficial in stereotactic radio surgery

Njeh, Christopher F.; Snyder, Karen; Cai, Jing

doi:10.1002/mp.13380

Cited by 10 publications

(10 citation statements)

References 23 publications

(24 reference statements)

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“…However, not all human and only few veterinary facilities report the use of image‐guidance with a six degree‐of‐freedom couch able to correct roll and pitch and achieving

\leq

0.5 mm positioning accuracy. Currently there is an ongoing controversial discussion in human radiation oncology whether a six degree‐of‐freedom couch is necessary for all patients or is for example only clinically beneficial and therefore indicated for certain patients, such as for stereotactic radiotherapy protocols 40,41 . Another limitation was that the quality of CT images could have been affected by outside variables (eg, slice thickness, field of view).…”

Section: Discussionmentioning

confidence: 99%

Estimation of planning organ at risk volumes for ocular structures in dogs undergoing three‐dimensional image‐guided periocular radiotherapy with rigid bite block immobilization

Wolf

Bley

Besserer

et al. 2021

Vet Radiology Ultrasound

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Planning organ at risk volume (PRV) estimates have been reported as methods for sparing organs at risk (OARs) during radiation therapy, especially for hypofractioned and/or dose‐escalated protocols. The objectives of this retrospective, analytical, observational study were to evaluate peri‐ocular OAR shifts and derive PRVs in a sample of dogs undergoing radiation therapy for periocular tumors. Inclusion criteria were as follows: dogs irradiated for periocular tumors, with 3D‐image‐guidance and at least four cone‐beam CTs (CBCTs) used for position verification, and positioning in a rigid bite block immobilization device. Peri‐ocular OARs were contoured on each CBCT and the systematic and random error of the shifts in relation to the planning CT position computed. The formula 1.3×Σ+0.5xσ was used to generate a PRV of each OAR in the dorsoventral, mediolateral, and craniocaudal axis. A total of 30 dogs were sampled, with 450 OARs contoured, and 2145 shifts assessed. The PRV expansion was qualitatively different for each organ (1‐4 mm for the dorsoventral and 1‐2 mm for the mediolateral and craniocaudal axes). Maximal PRV expansion was ≤4 mm and directional for the majority; most pronounced for corneas and retinas. Findings from the current study may help improve awareness of and minimization of radiation dose in peri‐ocular OARs for future canine patients. Because some OARs were difficult to visualize on CBCTs and/ or to delineate on the planning CT, authors recommend that PRV estimates be institution‐specific and applied with caution.

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“…However, not all human and only few veterinary facilities report the use of image‐guidance with a six degree‐of‐freedom couch able to correct roll and pitch and achieving

\leq

Section: Discussionmentioning

confidence: 99%

Estimation of planning organ at risk volumes for ocular structures in dogs undergoing three‐dimensional image‐guided periocular radiotherapy with rigid bite block immobilization

Wolf

Bley

Besserer

et al. 2021

Vet Radiology Ultrasound

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“…The current standard practice in image‐guided radiotherapy (IGRT) is to perform daily target position verification and online repositioning to account for the interfractional prostate movement 15,16 . However, most online repositioning methods can only partially correct for rotation shifts, as the magnitude of lateral rotations often exceeds the maximum possible pitch correction of the treatment couch 17,18 . Moreover, these methods generally ignore prostate deformations and the independent movement of the prostate and its surrounding organs at risk (OAR).…”

Section: Introductionmentioning

confidence: 99%

“… 15 , 16 However, most online repositioning methods can only partially correct for rotation shifts, as the magnitude of lateral rotations often exceeds the maximum possible pitch correction of the treatment couch. 17 , 18 Moreover, these methods generally ignore prostate deformations and the independent movement of the prostate and its surrounding organs at risk (OAR). The significance of these residual prostate rotations and deformations increases within the context of SBRT with focal boosting due to the localized dose escalation and the tighter than conventional margins that are used.…”

Section: Introductionmentioning

confidence: 99%

Automated treatment planning of prostate stereotactic body radiotherapy with focal boosting on a fast‐rotating O‐ring linac: Plan quality comparison with C‐arm linacs

Roover

Crijns

Dewit

et al. 2021

J Applied Clin Med Phys

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Purpose The integration of auto‐segmentation and automated treatment planning methods on a fast‐rotating O‐ring linac may improve the time efficiency of online adaptive radiotherapy workflows. This study investigates whether automated treatment planning of prostate SBRT with focal boosting on the O‐ring linac could generate plans that are of similar quality as those obtained through manual planning on clinical C‐arm linacs. Methods For 20 men with prostate cancer, reference treatment plans were generated on a TrueBeam STx C‐arm linac with HD120 MLC and a TrueBeam C‐arm linac with Millennium 120 MLC using 6 MV flattened dual arc VMAT. Manual planning on the Halcyon fast‐rotating O‐ring linac was performed using 6 MV FFF dual arc VMAT (HA2‐DL10) and triple arc VMAT (HA3‐DL10) to investigate the performance of the dual‐layer MLC system. Automated planning was performed for triple arc VMAT on the Halcyon linac (ET3‐DL10) using the automated planning algorithms of Ethos Treatment Planning. The prescribed dose was 35 Gy to the prostate and 30 Gy to the seminal vesicles in five fractions. The iso‐toxic focal boost to the intraprostatic tumor nodule(s) was aimed to receive up to 50 Gy. Plan deliverability was verified using portal image dosimetry measurements. Results Compared to the C‐arm linacs, ET3‐DL10 shows increased seminal vesicles PTV coverage (D99%) and reduced high‐dose spillage to the bladder (V37Gy) and urethra (D0.035cc) but this came at the cost of increased high‐dose spillage to the rectum (V38Gy) and a higher intermediate dose spillage (D2cm). No statistically significant differences were found when benchmarking HA2‐DL10 and HA3‐DL10 with the C‐arm linacs. All plans passed the patient‐specific QA tolerance limit. Conclusions Automated planning of prostate SBRT with focal boosting on the fast‐rotating O‐ring linac is feasible and achieves similar plan quality as those obtained on clinical C‐arm linacs using manual planning.

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“…For stereotactic radiosurgery/stereotactic body radiation therapy, a 6 degrees-offreedom (6D) couch is an essential component of the program to ensure the patient receives the most accurate and precise treatment. [1][2][3][4][5][6][7] Most modern Linacs (ie, TrueBeam) have an upgrade option to include a 6D couch from their own manufacturers. However, the 6D couch is not an upgradable option from the manufacturer for some older models of C-series Linacs.…”

Section: Introductionmentioning

confidence: 99%

Commissioning and Evaluation of a Third-Party 6 Degrees-of-Freedom Couch Used in Radiotherapy

Chan

Lim

et al. 2019

Technol Cancer Res Treat

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Purposes: The newly released Protura 6 degrees-of-freedom couch (CIVCO) has limited quality assurance protocols and pertinent publications. Herein, we report our experiences of the Protura system acceptance, commissioning, and quality assurance. Methods: The Protura system integration was tested with peripheral equipment on the following items: couch movement range limit, 6 degrees-of-freedom movement accuracy, weight test and couch sagging, system connection with Linac, isocentricity of couch and rotation alignment, kV and cone-beam computed tomography imaging of HexaCHECK with MIMI phantom (Standard Imaging), and an in-house custom 6 degrees-of-freedom quality assurance phantom. A couch transmission measurement was also performed. Results: The vertical, longitudinal, and lateral ranges of the 6 degrees-of-freedom couch pedestal are 43.9 to 0.0 cm, 24.6 to 149.5 cm, −20.6 to 20.7 cm, respectively. The couch movement accuracy was within 1 mm in all directions. The couch sagging with a 200 lbs (∼91 kg) evenly distributed object is 1.0 cm and 0.4° pitch in the distal end of the couch. The isocentricity of the couch was about 0.5 mm in diameter of all crosshair projections on the couch isocenter level, and the largest couch rotation alignment observed was (0.3°) at the couch angle of 90°. The deviation from the reference position (zero position) of the HexaCHECK phantom, measured by matching the cone-beam computed tomography with the reference planning computed tomography, was found to be below 0.2 mm in the anterior–posterior and right–left dimensions, 0.4 mm in superior–inferior dimension, and 0.1° in roll, pitch, and yaw directions. Conclusions: A 6 degrees-of-freedom quality assurance phantom is helpful for the commissioning and routine quality assurance tests. Due to the third-party integration with Linac, the system is prone to “double-correction” errors. A rigorous quality assurance program is the key to a successful clinical implementation of the Protura system.

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The use of six degrees of freedom couch is only clinically beneficial in stereotactic radio surgery

Cited by 10 publications

References 23 publications

Estimation of planning organ at risk volumes for ocular structures in dogs undergoing three‐dimensional image‐guided periocular radiotherapy with rigid bite block immobilization

Estimation of planning organ at risk volumes for ocular structures in dogs undergoing three‐dimensional image‐guided periocular radiotherapy with rigid bite block immobilization

Automated treatment planning of prostate stereotactic body radiotherapy with focal boosting on a fast‐rotating O‐ring linac: Plan quality comparison with C‐arm linacs

Commissioning and Evaluation of a Third-Party 6 Degrees-of-Freedom Couch Used in Radiotherapy

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