Cone-Beam Computed Tomography for On-Line Image Guidance of Lung Stereotactic Radiotherapy: Localization, Verification, and Intrafraction Tumor Position

Purdie, Thomas G.; Bissonnette, Jean Pierre; Franks, K.; Bezjak, Andrea; Payne, David G.; Sie, Fanny; Sharpe, Michael B.; Jaffray, David A.

doi:10.1016/j.ijrobp.2006.12.022

Cited by 298 publications

(247 citation statements)

References 28 publications

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“…Moreover, Purdie et al (43) reported that a significant intrafractional variation may occur when the time interval between localization and repeat CBCT imaging exceeds 34 minutes, whereas the total time from localization to treatment in our institution is approximately 15 minutes. In addition, post‐treatment CBCT verification may lead to overexposure of healthy adjacent tissues, skin, bone, lenses, and organs such as the pituitary and thyroid glands.…”

Section: Discussionmentioning

confidence: 73%

Assessment of setup uncertainties for various tumor sites when using daily CBCT for more than 2200 VMAT treatments

Baek

Kim

et al. 2014

J Applied Clin Med Phys

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The aim of this study was assess the patient setup errors for various tumor sites based on clinical data from a sufficient number of treatments with volumetric‐modulated arc therapy (VMAT) using daily pretreatment CBCT imaging guidance. In addition, we calculated and compared the planning target volume (PTV) margins for all disease sites based on an analysis of specific systematic and random errors in our institution. All patients underwent pretreatment kV‐CBCT imaging. The various tumor sites were divided into four categories; 21 brain (438 fractions), 35 head‐and‐neck tumors (H&N, 933 fractions), 19 thorax and abdomen tumors (T&A, 313 fractions), and 17 prostate cancer tumors (546 fractions). Overall distributions of setup corrections in all directions, frequencies of 3D vector lengths, institution‐specific setup error, and PTV margins were analyzed. The longitudinal distribution for the T&A site represented an asymmetric offset in the negative direction. Rotational distributions were comparable for all treatment sites, and the prostate site had the narrowest distribution of ≤±2∘. The cumulative frequencies of 3D vector length of ≥ 7 mm were rare for brain lesions and H&N, but more common for T&A and prostate lesions at 25.6% and 12.1%, respectively. The overall mean error for all treatment sites were within ±1 mm and ±0.1∘, with the exception of the T&A site, which had overall mean error of 2 mm in the negative longitudinal direction. The largest magnitude of systematic error and random error for the brain lesions and H&N was 1.4 mm in the translational directions, and 3.3 mm for T&A and prostate lesions. The PTV margins required in this analysis are ≤ 4 mm for the brain lesions and H&N in all translational directions, but ranged from 4 to 10 mm for T&A and prostate lesions. Analysis of each institution's specific setup errors using daily CBCT is essential for determining PTV margins and reducing setup uncertainties, because setup errors vary according to each immobilization system and patient.PACS number: 87.55.km

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Section: Discussionmentioning

confidence: 73%

Assessment of setup uncertainties for various tumor sites when using daily CBCT for more than 2200 VMAT treatments

Baek

Kim

et al. 2014

J Applied Clin Med Phys

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“…However, the engagement of a high number of couch rotations can extend the treatment times to potentially unfavourable lengths 4. It has previously been reported that for treatment times extending over 34 min that a baseline shift in tumour position of up to 5 mm can occur 5. Delivery times for lung SABR can vary depending on the equipment used, fractional dose, patient compliance and the delivery technique itself.…”

Section: Introductionmentioning

confidence: 99%

A comparison of three different VMAT techniques for the delivery of lung stereotactic ablative radiation therapy

Fitzgerald

Owen

Hargrave

et al. 2016

J of Medical Radiation Sci

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IntroductionThe purpose of this study was to investigate coplanar and non‐coplanar volumetric modulated arc therapy (VMAT) delivery techniques for stereotactic ablative radiation therapy (SABR) to the lung.MethodsFor ten patients who had already completed a course of radiation therapy for early stage lung cancer, three new SABR treatment plans were created using (1) a coplanar full arc (FA) technique, (2) a coplanar partial arc technique (PA) and (3) a non‐coplanar technique utilising three partial arcs (NCA). These plans were evaluated using planning target volume (PTV) coverage, dose to organs at risk, and high and intermediate dose constraints as incorporated by radiation therapy oncology group (RTOG) 1021.ResultsWhen the FA and PA techniques were compared to the NCA technique, on average the PTV coverage (V 54Gy) was similar (P = 0.15); FA (95.1%), PA (95.11%) and NCA (95.71%). The NCA resulted in a better conformity index (CI) of the prescription dose (0.89) when compared to the FA technique (0.88, P = 0.23) and the PA technique (0.83, P = 0.06). The NCA technique improved the intermediate dose constraints with a statistically significant difference for the D 2cm and R 50% when compared with the FA (P < 0.03 and <0.0001) and PA (P < 0.04 and <0.0001) techniques. The NCA technique reduced the maximum spinal cord dose by 2.72 and 4.2 Gy when compared to the PA and FA techniques respectively. Mean lung doses were 4.09, 4.31 and 3.98 Gy for the FA, PA and NCA techniques respectively.ConclusionThe NCA VMAT technique provided the highest compliance to RTOG 1021 when compared to coplanar techniques for lung SABR. However, single FA coplanar VMAT was suitable for 70% of patients when minor deviations to both the intermediate dose and organ at risk (OAR) constraints were accepted.

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“…The risk of a geographical miss or positioning error for hypo‐fractionated techniques can be greater than with conventional fractionation 1, 7, 8, 9, 10, 11, 12, 13. There are a number of immobilisation devices available, with most research being for SBRT, however, even for this indication unknowns remain.…”

Section: Introductionmentioning

confidence: 99%

A randomised comparison of three different immobilisation devices for thoracic and abdominal cancers

et al. 2016

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IntroductionPatient immobilisation is critically important for both highly conformal conventionally fractionated radiotherapy and for stereotactic body radiotherapy. Different immobilisation devices are available to maintain patient position for radiotherapy but the most suitable one remains unknown.MethodsForty‐five patients were randomly allocated to one of three immobilisation devices; the Q fix arm shuttle, BodyFIX without wrap or BodyFIX with wrap. Patients were imaged before and after treatment to ascertain intra‐fraction and inter‐fraction motion. Bony anatomy was used for matching to determine the positional accuracy of each device. Treatments were timed using a standard method. Patient comfort and staff satisfaction questionnaires were also issued to determine comfort, ease of use and preferences for each device.ResultsThe BodyFIX without wrap was the more accurate device; however, the differences between the devices were not statistically significant. The BodyFIX with wrap was found to take significantly longer to set up and set down compared to the arm shuttle and the BodyFIX without wrap (all P < 0.001). Patients (37%) marginally preferred the BodyFIX with wrap. Most (81%) staff preferred the BodyFIX without wrap.ConclusionImmobilisation using the BodyFIX without wrap was deemed to be suitable for clinical use. It was a clinically accurate device, the more efficient in terms of set up and set down time, the most preferred by staff and was accepted by patients.

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Cone-Beam Computed Tomography for On-Line Image Guidance of Lung Stereotactic Radiotherapy: Localization, Verification, and Intrafraction Tumor Position

Cited by 298 publications

References 28 publications

Assessment of setup uncertainties for various tumor sites when using daily CBCT for more than 2200 VMAT treatments

Assessment of setup uncertainties for various tumor sites when using daily CBCT for more than 2200 VMAT treatments

A comparison of three different VMAT techniques for the delivery of lung stereotactic ablative radiation therapy

A randomised comparison of three different immobilisation devices for thoracic and abdominal cancers

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