Evaluation of the deformation and corresponding dosimetric implications in prostate cancer treatment

Wen, Ning; Glide-Hurst, Carri K; Nurushev, T; Li, Xing; Kim, Jinkoo; Zhong, Hualiang; Liu, Dezhi; Liu, Manju; Burmeister, Jay; Movsas, Benjamin; Chetty, Indrin J.

doi:10.1088/0031-9155/57/17/5361

Cited by 38 publications

(37 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Then, deformable image registration (DIR) technique is utilized to establish the point-point correspondence between the planning computed tomography (CT) and the CBCT. The resulting deformation vector field (DVF) can be used for (1) propagating contoured region of interest (ROI) from one image to another [6] and (2) deformation of the re-planned dose maps to integrate the accumulated dose given to the patient [7].…”

Section: LI Et Al / Evaluation Of Ct-cbct Dir For Contour Propagamentioning

confidence: 99%

Evaluation of deformable image registration for contour propagation between CT and cone-beam CT images in adaptive head and neck radiotherapy

Zhang

Shi

et al. 2016

THC

View full text Add to dashboard Cite

Abstract. Deformable image registration (DIR) is a critical technic in adaptive radiotherapy (ART) to propagate contours between planning computerized tomography (CT) images and treatment CT/Cone-beam CT (CBCT) image to account for organ deformation for treatment re-planning. To validate the ability and accuracy of DIR algorithms in organ at risk (OAR) contours mapping, seven intensity-based DIR strategies are tested on the planning CT and weekly CBCT images from six Head & Neck cancer patients who underwent a 6 ∼ 7 weeks intensity-modulated radiation therapy (IMRT). Three similarity metrics, i.e. the Dice similarity coefficient (DSC), the percentage error (PE) and the Hausdorff distance (HD), are employed to measure the agreement between the propagated contours and the physician delineated ground truths. It is found that the performance of all the evaluated DIR algorithms declines as the treatment proceeds. No statistically significant performance difference is observed between different DIR algorithms (p > 0.05), except for the double force demons (DFD) which yields the worst result in terms of DSC and PE. For the metric HD, all the DIR algorithms behaved unsatisfactorily with no statistically significant performance difference (p = 0.273). These findings suggested that special care should be taken when utilizing the intensitybased DIR algorithms involved in this study to deform OAR contours between CT and CBCT, especially for those organs with low contrast.

show abstract

Section: LI Et Al / Evaluation Of Ct-cbct Dir For Contour Propagamentioning

confidence: 99%

Evaluation of deformable image registration for contour propagation between CT and cone-beam CT images in adaptive head and neck radiotherapy

Zhang

Shi

et al. 2016

THC

View full text Add to dashboard Cite

show abstract

“…The dose calculated on each CBCT image set was warped back to simulation CT image datasets to determine the ‘actual dose’ delivered to the patient. The dose delivered at each treatment fraction was accumulated to reflect the final dose given to the patient (Wen et al 2012). …”

Section: Methodsmentioning

confidence: 99%

“…However, IGRT cannot correct for daily deformation of the prostate gland and organs at risk (OAR) such as bladder and rectum. We have developed and previously validated an image guided adaptive radiotherapy (IGART) framework ‘in-house’, to track anatomical changes, such as displacement and deformation in the target and surrounding tissues (via daily cone beam CT (CBCT) images), and to perform daily dose accumulation (Wen et al 2012). The goal of this framework is to determine the actual daily dose delivered to the patient through the treatment course.…”

Section: Introductionmentioning

confidence: 99%

An assessment of PTV margin based on actual accumulated dose for prostate cancer radiotherapy

et al. 2013

Self Cite

View full text Add to dashboard Cite

The purpose of this work is to present the results of a margin reduction study involving dosimetric and radiobiologic assessment of cumulative dose distributions, computed using an image guided adaptive radiotherapy based framework. Eight prostate cancer patients, treated with 7–9, 6 MV, intensity modulated radiation therapy (IMRT) fields, were included in this study. The workflow consists of cone beam CT (CBCT) based localization, deformable image registration of the CBCT to simulation CT image datasets (SIMCT), dose reconstruction and dose accumulation on the SIM-CT, and plan evaluation using radiobiological models. For each patient, three IMRT plans were generated with different margins applied to the CTV. The PTV margin for the original plan was 10 mm and 6 mm at the prostate/anterior rectal wall interface (10/6 mm) and was reduced to: (a) 5/3 mm, and (b) 3 mm uniformly. The average percent reductions in predicted tumor control probability (TCP) in the accumulated (actual) plans in comparison to the original plans over eight patients were 0.4%, 0.7% and 11.0% with 10/6 mm, 5/3 mm and 3 mm uniform margin respectively. The mean increase in predicted normal tissue complication probability (NTCP) for grades 2/3 rectal bleeding for the actual plans in comparison to the static plans with margins of 10/6, 5/3 and 3 mm uniformly was 3.5%, 2.8% and 2.4% respectively. For the actual dose distributions, predicted NTCP for late rectal bleeding was reduced by 3.6% on average when the margin was reduced from 10/6 mm to 5/3 mm, and further reduced by 1.0% on average when the margin was reduced to 3 mm. The average reduction in complication free tumor control probability (P+) in the actual plans in comparison to the original plans with margins of 10/6, 5/3 and 3 mm was 3.7%, 2.4% and 13.6% correspondingly. The significant reduction of TCP and P+ in the actual plan with 3 mm margin came from one outlier, where individualizing patient treatment plans through margin adaptation based on biological models, might yield higher quality treatments.

show abstract

“…4 On-board dose verification not only enables treatment dose tracking and treatment quality assessment but also facilitates image-guided adaptive radiation therapy. [41][42][43] The MM-FD solves the scan time/dose limitations of the 4D-CBCT imaging and provides high quality images for accurate target delineation and dose verification, making lung adaptive radiotherapy more promising.…”

Section: C Additional Benefits Of Mm-fd Based Image Estimationmentioning

confidence: 99%

Dosimetric verification of lung cancer treatment using the CBCTs estimated from limited‐angle on‐board projections

2015

View full text Add to dashboard Cite

Purpose: Lung cancer treatment is susceptible to treatment errors caused by interfractional anatomical and respirational variations of the patient. On-board treatment dose verification is especially critical for the lung stereotactic body radiation therapy due to its high fractional dose. This study investigates the feasibility of using cone-beam (CB)CT images estimated by a motion modeling and free-form deformation (MM-FD) technique for on-board dose verification. Methods: Both digital and physical phantom studies were performed. Various interfractional variations featuring patient motion pattern change, tumor size change, and tumor average position change were simulated from planning CT to on-board images. The doses calculated on the planning CT (planned doses), the on-board CBCT estimated by MM-FD (MM-FD doses), and the on-board CBCT reconstructed by the conventional Feldkamp-Davis-Kress (FDK) algorithm (FDK doses) were compared to the on-board dose calculated on the "gold-standard" on-board images (gold-standard doses). The absolute deviations of minimum dose (∆D min ), maximum dose (∆D max ), and mean dose (∆D mean ), and the absolute deviations of prescription dose coverage (∆V 100% ) were evaluated for the planning target volume (PTV). In addition, 4D on-board treatment dose accumulations were performed using 4D-CBCT images estimated by MM-FD in the physical phantom study. The accumulated doses were compared to those measured using optically stimulated luminescence (OSL) detectors and radiochromic films. Results: Compared with the planned doses and the FDK doses, the MM-FD doses matched much better with the gold-standard doses. For the digital phantom study, the average (± standard deviation) ∆D min , ∆D max , ∆D mean , and ∆V 100% (values normalized by the prescription dose or the total PTV) between the planned and the gold-standard PTV doses were 32.9% (±28.6%), 3.0% (±2.9%), 3.8% (±4.0%), and 15.4% (±12.4%), respectively. The corresponding values of FDK PTV doses were 1.6% (±1.9%), 1.2% (±0.6%), 2.2% (±0.8%), and 17.4% (±15.3%), respectively. In contrast, the corresponding values of MM-FD PTV doses were 0.3% (±0.2%), 0.9% (±0.6%), 0.6% (±0.4%), and 1.0% (±0.8%), respectively. Similarly, for the physical phantom study, the average ∆D min , ∆D max , ∆D mean , and ∆V 100% of planned PTV doses were 38.1% (±30.8%), 3.5% (±5.1%), 3.0% (±2.6%), and 8.8% (±8.0%), respectively. The corresponding values of FDK PTV doses were 5.8% (±4.5%), 1.6% (±1.6%), 2.0% (±0.9%), and 9.3% (±10.5%), respectively. In contrast, the corresponding values of MM-FD PTV doses were 0.4% (±0.8%), 0.8% (±1.0%), 0.5% (±0.4%), and 0.8% (±0.8%), respectively. For the 4D dose accumulation study, the average (± standard deviation) absolute dose deviation (normalized by local doses) between the accumulated doses and the OSL measured doses was 3.3% (±2.7%). The average gamma index (3%/3 mm) between the accumulated doses and the radiochromic film measured doses was 94.5% (±2.5%). Conclusions: MM-FD estimated 4D-CBCT enables accurate on-board do...

show abstract

Evaluation of the deformation and corresponding dosimetric implications in prostate cancer treatment

Cited by 38 publications

References 34 publications

Evaluation of deformable image registration for contour propagation between CT and cone-beam CT images in adaptive head and neck radiotherapy

Evaluation of deformable image registration for contour propagation between CT and cone-beam CT images in adaptive head and neck radiotherapy

An assessment of PTV margin based on actual accumulated dose for prostate cancer radiotherapy

Dosimetric verification of lung cancer treatment using the CBCTs estimated from limited‐angle on‐board projections

Contact Info

Product

Resources

About