Magnetic resonance-only simulation and dose calculation in external beam radiation therapy: a feasibility study for pelvic cancers

Kemppainen, Reko; Suilamo, Sami; Tuokkola, Terhi; Lindholm, Paula; Deppe, Martin H.; Keyriläinen, Jani

doi:10.1080/0284186x.2017.1293290

Cited by 38 publications

(59 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dose deviations obtained in this study are in line with previously published studies on rectal cancer patients [21,22], which reported dose differences within 1.5% and to other studies in the pelvic area reporting dose differences within 2% [31,15,16]. As highlighted in the Supplementary material, the observed dose differences may be related to smaller body contour on sCT with respect to CT images.…”

Section: Discussionsupporting

confidence: 91%

“…Investigations into sCT generation mostly focused on brain and prostate cancer patients [16,17], with vendors recently providing certified solutions for prostate cancer radiotherapy [18][19][20]. Only two publications investigated the feasibility of MR-only radiotherapy calculations for rectal cancer patients [21,22]. These two contributions focused solely on the dosimetric accuracy of MR-based dose calculation without investigating the use of sCT as a reference for position verification.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Feasibility of magnetic resonance imaging-only rectum radiotherapy with a commercial synthetic computed tomography generation solution

Maspero

Tyyger

Tijssen

et al. 2018

Physics and Imaging in Radiation Oncology

View full text Add to dashboard Cite

A B S T R A C TBackground and purpose: Synthetic computed tomography (sCT) images enable magnetic resonance (MR)-based dose calculations. This work investigated whether a commercially available sCT generation solution was suitable for accurate dose calculations and position verification on patients with rectal cancer. Material and methods: For twenty rectal cancer patients computed tomography (CT) images were rigidly registered to sCT images. Clinical volumetric modulated arc therapy plans were recalculated on registered CT and sCT images. Dose deviations were determined through gamma and voxelwise analysis. The impact on position verification was investigated by identifying differences in translations and rotation between cone-beam CT (CBCT) to CT and CBCT to sCT registrations. Results: Across twenty patients, within a threshold of 90% of the prescription dose, a gamma analysis (2%, 2 mm) mean pass rate of 95.2 ± 4.0% ( ± 1 ) and mean dose deviation of −0.3 ± 0.2% of prescription dose were obtained. The mean difference of translations and rotations over ten patients (76 CBCTs) was < 1 mm and < 0.5°in all directions. In the sole posterior-anterior direction a mean systematic shift of 0.7 ± 0.6 mm was found. Conclusions: Accurate MR-based dose calculations using a commercial sCT generation method were clinically feasible for treatment of rectal cancer patients. The accuracy of position verification was clinically acceptable. However, before clinical implementation future investigations will be performed to determine the origin of the systematic shift.

show abstract

Section: Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Feasibility of magnetic resonance imaging-only rectum radiotherapy with a commercial synthetic computed tomography generation solution

Maspero

Tyyger

Tijssen

et al. 2018

Physics and Imaging in Radiation Oncology

View full text Add to dashboard Cite

show abstract

“…Additional artifacts can derive from patient induced distortions, such as susceptibility and chemical shift. Previous studies have shown that with geometric accuracy better than 2 mm within the entire FOV it is possible to achieve clinically feasible dose calculation accuracy for MRI-only RTP [21,23,[38][39][40][41]. The geometric accuracy of the applied MR platforms was sufficient for MRI-only RT [10,11,21,23,37].…”

Section: Discussionmentioning

confidence: 99%

Intensity-based dual model method for generation of synthetic CT images from standard T2-weighted MR images – Generalized technique for four different MR scanners

Koivula

Kapanen

Seppälä

et al. 2017

Radiotherapy and Oncology

View full text Add to dashboard Cite

show abstract

“…When focusing on the pelvis area, many methods have been proposed and evaluated for radiotherapy of prostate cancer (Edmund andNyholm 2017, Johnstone et al 2017), showing dose deviations below 2% with respect to CT-based dose calculations. Only three contributions investigated the accuracy of MR-based dose calculations for locations other than prostate within the pelvic area (Kemppainen et al 2017, Liu et al 2017, Wang et al 2018. Moreover, no attention has been specifically dedicated to the time required to generate sCT, which should be of the order of minutes to allow daily replanning during MRgRT as, for example, underlined by Raaymakers et al (2017).…”

Section: Introductionmentioning

confidence: 99%

Dose evaluation of fast synthetic-CT generation using a generative adversarial network for general pelvis MR-only radiotherapy

et al. 2018

View full text Add to dashboard Cite

To enable magnetic resonance (MR)-only radiotherapy and facilitate modelling of radiation attenuation in humans, synthetic CT (sCT) images need to be generated. Considering the application of MR-guided radiotherapy and online adaptive replanning, sCT generation should occur within minutes. This work aims at assessing whether an existing deep learning network can rapidly generate sCT images for accurate MR-based dose calculations in the entire pelvis. A study was conducted on data of 91 patients with prostate (59), rectal (18) and cervical (14) cancer who underwent external beam radiotherapy acquiring both CT and MRI for patients' simulation. Dixon reconstructed water, fat and in-phase images obtained from a conventional dual gradient-recalled echo sequence were used to generate sCT images. A conditional generative adversarial network (cGAN) was trained in a paired fashion on 2D transverse slices of 32 prostate cancer patients. The trained network was tested on the remaining patients to generate sCT images. For 30 patients in the test set, dose recalculations of the clinical plan were performed on sCT images. Dose distributions were evaluated comparing voxel-based dose differences, gamma and dose-volume histogram (DVH) analysis. The sCT generation required 5.6 s and 21 s for a single patient volume on a GPU and CPU, respectively. On average, sCT images resulted in a higher dose to the target of maximum 0.3%. The average gamma pass rates using the 3%, 3 mm and 2%, 2 mm criteria were above 97 and 91%, respectively, for all volumes of interests considered. All DVH points calculated on sCT differed less than ±2.5% from the corresponding points on CT. Results suggest that accurate MR-based dose calculation using sCT images generated with a cGAN trained on prostate cancer patients is feasible for the entire pelvis. The sCT generation was sufficiently fast for integration in an MR-guided radiotherapy workflow.

show abstract

Magnetic resonance-only simulation and dose calculation in external beam radiation therapy: a feasibility study for pelvic cancers

Abstract: According to the comparison, using pCT for clinical EBRT planning and dose calculation in the three investigated types of pelvic cancers is feasible. Further studies are required to demonstrate the applicability to a larger cohort of patients.

Cited by 38 publications

References 20 publications

Feasibility of magnetic resonance imaging-only rectum radiotherapy with a commercial synthetic computed tomography generation solution

Feasibility of magnetic resonance imaging-only rectum radiotherapy with a commercial synthetic computed tomography generation solution

Intensity-based dual model method for generation of synthetic CT images from standard T2-weighted MR images – Generalized technique for four different MR scanners

Dose evaluation of fast synthetic-CT generation using a generative adversarial network for general pelvis MR-only radiotherapy

Contact Info

Product

Resources

About