Daily kV cone-beam CT and deformable image registration as a method for studying dosimetric consequences of anatomic changes in adaptive IMRT of head and neck cancer

Elstrøm, U.V.; Wysocka, Barbara; Muren, L.P.; Petersen, Jørgen B. B.; Grau, Cai

doi:10.3109/0284186x.2010.500304

Cited by 76 publications

(42 citation statements)

References 25 publications

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“…The specific targeting and attenuation of radiation are unique to the patient's anatomy at the time of the planning CT (PCT) simulation, but these conditions are difficult to maintain throughout an entire course of treatment due to changes in anatomy 1, 2, 3, 4. To account for changes in patient anatomy, plan modification may be required during the treatment course to ensure accurate targeting.…”

Section: Introductionmentioning

confidence: 99%

Online daily assessment of dose change in head and neck radiotherapy without dose‐recalculation

Vickress

Battista

Barnett

et al. 2018

J Applied Clin Med Phys

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BackgroundHead and neck cancers are commonly treated with radiation therapy, but due to possible volume changes, plan adaptation may be required during the course of treatment. Currently, plan adaptations consume significant clinical resources. Existing methods to evaluate the need for plan adaptation requires deformable image registration (DIR) to a new CT simulation or daily cone beam CT (CBCT) images and the recalculation of the dose distribution. In this study, we explore a tool to assist the decision for plan adaptation using a CBCT without re‐computation of dose, allowing for rapid online assessment.MethodsThis study involved 18 head and neck cancer patients treated with CBCT image guidance who had their treatment plan modified based on a new CT simulation (ReCT). Dose changes were estimated using different methods and compared to the current gold standard of using DIR between the planning CT scan (PCT) and ReCT with recomputed dose. The first and second methods used DIR between the PCT and daily CBCT with the planned dose or recalculated dose from the ReCT respectively, with the dose transferred to the CBCT using rigid registration. The necessity of plan adaptation was assessed by the change in dose to 95% of the planning target volume (D95) and mean dose to the parotids.ResultsThe treatment plans were adapted clinically for all 18 patients but only 7 actually needed an adaptation yielding 11 unnecessary adaptations. Applying a method using the daily CBCT with the planned dose distribution would have yielded only four unnecessary adaptations and no missed adaptations: a significant improvement from that done clinically.ConclusionUsing the DIR between the planning CT and daily CBCT can flag cases for plan adaptation before every fraction while not requiring a new re‐planning CT scan and dose recalculation.

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Section: Introductionmentioning

confidence: 99%

Online daily assessment of dose change in head and neck radiotherapy without dose‐recalculation

Vickress

Battista

Barnett

et al. 2018

J Applied Clin Med Phys

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“…Replanning requires repeated contouring of target volumes and normal tissues, which remains a time consuming task, even for experienced clinicians. There is a growing array of commercial software aimed at easing this burden by automatic contouring, utilizing novel deformable image registration (DIR) techniques to propagate one set of contours from an initial CT to fit the anatomy of a second CT [13,14]. Such techniques have been found to reduce contouring time considerably [15,16].…”

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confidence: 99%

Accuracy of software-assisted contour propagation from planning CT to cone beam CT in head and neck radiotherapy

et al. 2016

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Background: Autocontouring improves workflow in computed tomography (CT)-based dose planning, but could also potentially play a role for optimal use of daily cone beam CT (CBCT) in adaptive radiotherapy. This study aims to determine the accuracy of a deformable image registration (DIR) algorithm for organs at risk (OAR) in the neck region, when applied to CBCT. Material and methods: For 30 head and neck cancer (HNC) patients 14 OARs including parotid glands, swallowing structures and spinal cord were delineated. Contours were propagated by DIR from CT to the CBCTs of the first and last treatment fraction. An indirect approach, propagating contours to the first CBCT and from there to the last CBCT was also tested. Propagated contours were compared to manually corrected contours by Dice similarity coefficient (DSC) and Hausdorff distance (HD). Dose was recalculated on CBCTs and dosimetric consequences of uncertainties in DIR were reviewed. Results: Mean DSC values of !0.8 were considered adequate and were achieved in tongue base (0.91), esophagus (0.85), glottic (0.81) and supraglottic larynx (0.83), inferior pharyngeal constrictor muscle (0.84), spinal cord (0.89) and all salivary glands in the first CBCT. For the last CBCT by direct propagation, adequate DSC values were achieved for tongue base (0.85), esophagus (0.84), spinal cord (0.87) and all salivary glands. Using indirect propagation only tongue base (0.80) and parotid glands (0.87) were !0.8. Mean relative dose difference between automated and corrected contours was within ±2.5% of planed dose except for esophagus inlet (-4.5%) and esophagus (5.0%) for the last CBCT using indirect propagation. Conclusion: Compared to manually corrected contours, the DIR algorithm was accurate for use in CBCT images of HNC patients and the minor inaccuracies had little consequence for mean dose in most clinically relevant OAR. The method can thus enable a more automated segmentation of CBCT for use in adaptive radiotherapy.

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“…In this study, we discovered that for the left, right lung, and total lungs mean dose accumulation, V 5 , and V 10 , the spinal cord maximum dose accumulation, the DA plans are lower than the CT plans. All parameters in the fractional radiotherapy plan was similar to Dr. Elstrøm (2) and his fellows research. Therefore, based on the target volumes and the normal organs accumulation dose, we can increase the target volume dose while reducing normal tissues dose.…”

Section: Discussionmentioning

confidence: 95%

A Study of the Anatomic Changes and Dosimetric Consequences in Adaptive CRT of Non-Small-Cell Lung Cancer Using Deformable CT and CBCT Image Registration

Hou

et al. 2014

Technol Cancer Res Treat

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The aim of this study is to evaluate anatomic lung tumor changes and dosimetric consequences utilizing the deformable daily kilovolt (KV) cone-beam computer tomography (CBCT) image registration. Five patients diagnosed with NSCLC were treated with three-dimensional conformal radiotherapy (3D CRT) and 10 daily KV CBCT image sets were acquired for each patient. Each CBCT image and plan CT were imported into the deformable image registration (DIR) system. The plan CT image was deformed by the DIR system and a new contour on CBCT was obtained by using the auto-contouring function of the DIR. These contours were individually marked as CBCT f1, CBCT f2,…, and CBCT f10, and imported into a treatment planning system (TPS). The daily CBCT plan was individually generated with the same planning criteria based on new contours. These plans were individually marked as CBCTp1, CBCTp2,…, and CBCTp10, followed by generating a dose accumulation plan (DA plan) in original pCT image contour sets by adding all CBCT plans using Varian Eclipse TPS. The maximum, minimum and mean doses to the plan target volume (PTV) in the 5 DA plans were the same with the CT plans. However, the volume of radiation 5, 10, 20, 30, and 50 Gy of the total lungs in DA plans were less than those of the CT plans. The maximum dose of the spinal cord in the DA plans were average 27.96% less than the CT plans. The mean dose for the left, right, and total lungs in the DA plans were reduced by 13.80%, 23.65%, and 12.96%, respectively. The adaptive 3D CRT based on the deformable registration can reduce the dose to the lung and the spinal cord with the same PTV dose coverage. Moreover, it provides a method for further adaptive radiotherapy exploration.

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Daily kV cone-beam CT and deformable image registration as a method for studying dosimetric consequences of anatomic changes in adaptive IMRT of head and neck cancer

Cited by 76 publications

References 25 publications

Online daily assessment of dose change in head and neck radiotherapy without dose‐recalculation

Online daily assessment of dose change in head and neck radiotherapy without dose‐recalculation

Accuracy of software-assisted contour propagation from planning CT to cone beam CT in head and neck radiotherapy

A Study of the Anatomic Changes and Dosimetric Consequences in Adaptive CRT of Non-Small-Cell Lung Cancer Using Deformable CT and CBCT Image Registration

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