Assessment of Three-dimensional Set-up Errors using Megavoltage Computed Tomography (MVCT) during Image-guided Intensity-modulated Radiation Therapy (IMRT) for Craniospinal Irradiation (CSI) on Helical Tomotherapy (HT)

Gupta, Tejpal; Upasani, M.; Master, Zubin; Patil, Anita; Phurailatpam, Reena; Nojin, Siji; Kannan, Sadhana; Godasastri, Jayant; Jalali, Rakesh

doi:10.7785/tcrt.2012.500391

Cited by 14 publications

(14 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their maximum mean deviation, in any direction, was found to be 6 mm while ours was 24 mm. Our results were, however, comparable to other similar studies investigating errors, uncertainties and margins for craniospinal treatments [34][35][36]. Stoiber et al [34] found a maximum deviation of 18 mm and 10°, again compared to our 24 mm and 9.6°.…”

Section: Discussionsupporting

confidence: 91%

See 1 more Smart Citation

Residual positioning errors and uncertainties for pediatric craniospinal irradiation and the impact of image guidance

et al. 2020

View full text Add to dashboard Cite

Background: Optimal alignment is of utmost importance when treating pediatric patients with craniospinal irradiation (CSI), especially with regards to field junctions and multiple isocenters and techniques applying high dose gradients. Here, we investigated the setup errors and uncertainties for pediatric CSI using different setup verification protocols. Methods: A total of 38 pediatric patients treated with CSI were identified for whom treatment records and setup images were available. The setup images were registered retrospectively to the reference image using an automated tool and matching on bony anatomy, subsequently, the impact of different correction protocols was simulated. Results: For an action-level (AL)-protocol and a non-action level (NAL)-protocol, the translational residual setup error can be as large as 24 mm for an individual patient during a single fraction, and the rotational error as large as 6.1°. With daily IGRT, the maximum setup errors were reduced to 1 mm translational and 5.4°rotational versus 1 mm translational and 2.4°rotational for 3-and 6-degrees of freedom (DoF) couch shifts, respectively. With a daily 6-DoF IGRT protocol for a wide field junction irradiation technique, the residual positioning uncertainty was below 1 mm and 1°for translational and rotational directions, respectively. The largest rotational uncertainty was found for the patients' roll even though this was the least common type of rotational error, while the largest translational uncertainty was found in the patients' anterior-posterior-axis. Conclusions: These results allow for informed margin calculation and robust optimization of treatments. Daily IGRT is the superior choice for setup of pediatric patients treated with CSI, although centers that do not have this option could use the results presented here to improve their margins and uncertainty estimates for a more accurate treatment alignment.

show abstract

Section: Discussionsupporting

confidence: 91%

“…Stoiber et al [34] found a maximum deviation of 18 mm and 10°, again compared to our 24 mm and 9.6°. Gupta et al [35] found a maximum deviation of 20 mm. Interestingly, Thondykandy et al [36] found the SU to be larger than the RU for CSI while our results show the opposite.…”

Section: Discussionmentioning

confidence: 95%

Residual positioning errors and uncertainties for pediatric craniospinal irradiation and the impact of image guidance

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The alignment of the patient was done rectilinearly on the couch. [ 13 ] Figure 1 shows the immobilization devices used at our institution.…”

Section: Methodsmentioning

confidence: 99%

“…For CSI, the imaging was carried out daily, and the correction was applied, based on the hospital protocol. [ 13 ]…”

Section: Methodsmentioning

confidence: 99%

Setup error analysis in helical tomotherapy based image-guided radiation therapy treatments

Thondykandy¹,

Swamidas²,

Agarwal³

et al. 2015

J Med Phys

Self Cite

View full text Add to dashboard Cite

The adequacy of setup margins for various sites in patients treated with helical tomotherapy was investigated. A total of 102 patients were investigated. The breakdown of the patients were as follows: Twenty-five patients each in brain, head and neck (H and N), and pelvis, while 12 patients in lung and 15 in craniospinal irradiation (CSI). Patients were immobilized on the institutional protocol. Altogether 2686 megavoltage computed tomography images were analyzed with 672, 747, 622, 333, and 312 fractions, respectively, from brain, H and N, pelvis, lung, and CSI. Overall systematic and random errors were calculated in three translational and three rotational directions. Setup margins were evaluated using van Herk formula. The calculated margins were compared with the margins in the clinical use for various directions and sites. We found that the clinical isotropic margin of 3 mm was adequate for brain patients. However, in the longitudinal direction it was found to be out of margin by 0.7 mm. In H and N, the calculated margins were well within the isotropic margin of 5 mm which is in clinical use. In pelvis, the calculated margin was within the limits, 8.3 mm versus 10 mm only in longitudinal direction, however, in vertical and lateral directions the calculated margins were out of clinical margins 11 mm versus 10 mm, and 8.7 mm versus 7.0, mm respectively. In lung, all the calculated margins were well within the margins used clinically. In CSI, the variation was found in the middle spine in the longitudinal direction. The clinical margins used in our hospital are adequate enough for sites H and N, lung, and brain, however, for CSI and pelvis the margins were found to be out of clinical margins.

show abstract

“…range of MVCT compared to the long range of the treatment field in the craniocaudal direction required for CSI using HT (HT-CSI) 16,27,28 . Among these drawbacks, in terms of the image quality, Forrest et al and Meeks et al reported that MVCT can provide sufficient image quality for tumor identification and setup verification, despite its low-contrast resolution for soft tissues 29,30 .…”

mentioning

confidence: 99%

Practical aspects of the application of helical tomotherapy for craniospinal irradiation

Lee

Kim

et al. 2021

Sci Rep

View full text Add to dashboard Cite

We investigated the practical aspects of the application of craniospinal irradiation using helical tomotherapy (HT-CSI) by evaluating interfractional setup errors and intrafractional movement during each treatment in 83 patients undergoing HT-CSI between January 2014 and December 2018. Interfractional setup errors in each axis (mediolateral; ML, craniocaudal; CC, and anteroposterior; AP) were assessed as differences between pre-treatment megavoltage computed tomography (MVCT) images scanned (zygomatic arch to the C4 spine) and planning CT images. Intrafractional movements were evaluated as the difference between pre-treatment and post-treatment MVCT (T12–L4 spine) images at each fraction. Median interfractional setup error was acceptable in every axis (ML: 1.6 mm, CC: 1.9 mm, AP: 3.1 mm). Seven patients (8.4%) experienced significant intrafractional displacement from 1 to 10 fractions (0.34% for ML, 0.74% for CC, 1.21% for AP). Weight loss grade 1+ during treatment (p = 0.016) was an independent risk factor for significant intrafractional displacement. The risk factor for significant intrafractional movement in pediatric patients was weight loss grade 1+ (p = 0.020), while there was no factor in adults. HT-CSI could be a feasible treatment modality with acceptable setup verification. Inter- and intrafractional errors were acceptable; paying attention to weight loss during treatment is necessary, especially in pediatric patients.

show abstract

Assessment of Three-dimensional Set-up Errors using Megavoltage Computed Tomography (MVCT) during Image-guided Intensity-modulated Radiation Therapy (IMRT) for Craniospinal Irradiation (CSI) on Helical Tomotherapy (HT)

Cited by 14 publications

References 27 publications

Residual positioning errors and uncertainties for pediatric craniospinal irradiation and the impact of image guidance

Residual positioning errors and uncertainties for pediatric craniospinal irradiation and the impact of image guidance

Setup error analysis in helical tomotherapy based image-guided radiation therapy treatments

Practical aspects of the application of helical tomotherapy for craniospinal irradiation

Contact Info

Product

Resources

About