Dose Escalation for Locally Advanced Lung Cancer Using Adaptive Radiation Therapy With Simultaneous Integrated Volume-Adapted Boost

Weiss, Elisabeth; Fatyga, M.; Wu, Yan; Dogan, Nesrin; Balik, Salim; Sleeman, William C.; Hugo, Geoffrey D.

doi:10.1016/j.ijrobp.2012.12.027

Cited by 35 publications

(28 citation statements)

References 16 publications

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“…9 In another study which adapted at weeks 2 and 4 conducted by Weiss et al, an average increase of 13.4 Gy with a maximum of 23.4 Gy was achieved. 10 These values are larger than those reported here for daily adaptation; differences may be attributed to volumes used to estimate escalation, i.e., in this work, dose was escalated to the CTV as opposed to primary tumor. Furthermore, average primary tumor regression for the synthetic dataset was smaller than those other researchers have observed clinically as previously noted.…”

Section: Discussionmentioning

confidence: 54%

“…[7][8][9][10] These works implement various replanning schedules ranging from single to weekly adaptations and demonstrate a patient-specific benefit for adaptive plans in the context of tumor regression. While a variety of schedules have been implemented by the respective authors, systematic comparisons between schedules of the varying adaptive frequency have not been performed; furthermore, the nature of tradeoff between the replanning frequency and adaptive benefit is not understood.…”

Section: Introductionmentioning

confidence: 99%

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Benefits of adaptive radiation therapy in lung cancer as a function of replanning frequency

et al. 2016

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Purpose: To quantify the potential benefit associated with daily replanning in lung cancer in terms of normal tissue dose sparing and to characterize the tradeoff between adaptive benefit and replanning frequency. Methods: A set of synthetic images and contours, derived from weekly active breathing control images of 12 patients who underwent radiation therapy treatment for nonsmall cell lung cancer, is generated for each fraction of treatment using principal component analysis in a way that preserves temporal anatomical trends (e.g., tumor regression). Daily synthetic images and contours are used to simulate four different treatment scenarios: (1) a "no-adapt" scenario that simulates delivery of an initial plan throughout treatment, (2) a "midadapt" scenario that implements a single replan for fraction 18, (3) a "weekly adapt" scenario that simulates weekly adaptations, and (4) a "full-adapt" scenario that simulates daily replanning. An initial intensity modulated radiation therapy plan is created for each patient and replanning is carried out in an automated fashion by reoptimizing beam apertures and weights. Dose is calculated on each image and accumulated to the first in the series using deformable mappings utilized in synthetic image creation for comparison between simulated treatments. Results: Target coverage was maintained and cord tolerance was not exceeded for any of the adaptive simulations. Average reductions in mean lung dose (MLD) and volume of lung receiving 20 Gy or more (V 20 lung ) were 65 ± 49 cGy (p = 0.000 01) and 1.1% ± 1.2% (p = 0.0006), respectively, for all patients. The largest reduction in MLD for a single patient was 162 cGy, which allowed an isotoxic escalation of the target dose of 1668 cGy. Average reductions in cord max dose, mean esophageal dose (MED), dose received by 66% of the heart (D66 heart ), and dose received by 33% of the heart (D33 heart ), were 158 ± 280, 117 ± 121, 37 ± 77, and 99 ± 120 cGy, respectively. Average incremental reductions in MLD for the midadapt, weekly adapt, and full-adapt treatments were 38, 18, and 8 cGy, respectively. Incremental reductions in MED for the same treatments were 57, 37, and 23 cGy. Reductions in MLD and MED for the full-adapt treatment were correlated with the absolute decrease in the planning target volume (r = 0.34 and r = 0.26). Conclusions: Adaptive radiation therapy for lung cancer yields clinically relevant reductions in normal tissue doses for frequencies of adaptation ranging from a single replan up to daily replanning. Increased frequencies of adaptation result in additional benefit while magnitude of benefit decreases. C 2016 American Association of Physicists in Medicine. [http://dx

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Section: Discussionmentioning

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Benefits of adaptive radiation therapy in lung cancer as a function of replanning frequency

et al. 2016

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“…With improved RT planning and delivery techniques, it is possible to have the normal lung and heart better spared from radiation, and dose-intensified RT schedules safely administered [69]. It has been found that for patients with locally advanced NSCLC, ART may increase radiation dose to the residual tumor target up to 80 Gy on average, without increasing dose to normal tissue [74,75]. However, more clinical data should be collected to evaluate the impact of ART on normal tissue dose reduction.…”

Section: Prescription For Adaptive Planningmentioning

confidence: 99%

“…It has been reported that plan adaptation performed around fraction 15 and fraction 20 is most diametrically efficient for concurrent and sequential chemoradiotherapy, respectively [79]. Based on iso-toxic Mean Lung Dose (MLD), re-planning twice at weeks 2 and 4 may achieve an average escalation of 13.4 Gy [75], and at weeks 3 and 5 may have an average increase of 7 Gy or a reduction in MLD of approximately 8% [12]. Since tumor shrinkage depends on many factors such as tumor histology, location, stage and imaging modality used in the volume measurement, the optimal time point for plan adaptation and its dosimetric gain could be different for individual patients.…”

Section: Decision For Plan Adaptationmentioning

confidence: 99%

Recent Advances and Challenges in Adaptive Radiotherapy for Patients with Locally Advanced NSCLC

Zhong¹,

Jin²

2017

Ann Radiat Ther Oncol

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Patients with locally advanced Non-Small Cell Lung Cancer (NSCLC) often show significant tumor regression and anatomical changes during the course of radiation treatment. As reaction to these changes, planned treatment parameter will be modified multiple times so that the overall treatment can be optimized. This is termed as Adaptive Radiotherapy (ART). While significant progress has been made in the past few years for development of different ART techniques, challenges still exist in implementation of this treatment modality in clinic. In this topical review, techniques used in different ART components will be briefly reviewed, and strategies to maximize the efficacy of adaptive treatment will also be discussed.

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“…The delivered doses can be calculated on a reference image dataset by using deformable dose mapping and accumulation techniques (Mohan et al, 2005, Heath and Seuntjens, 2006). It has been demonstrated that adaptive radiotherapy incorporating deformable dose accumulation (DDA) may facilitate dose escalation and normal tissue sparing (Weiss et al, 2013). Among these techniques, image-intensity-based deformable registration incorporating dose interpolation is a widely used DDA method (Rosu et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Adaptive radiotherapy for NSCLC patients: utilizing the principle of energy conservation to evaluate dose mapping operations

Zhong

Chetty

2017

Phys. Med. Biol.

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Tumor regression during the course of fractionated radiotherapy confounds the ability to accurately estimate the total dose delivered to tumor targets. Here we present a new criterion to improve the accuracy of image intensity-based dose mapping operations for adaptive radiotherapy for patients with non-small cell lung cancer (NSCLC). Six NSCLC patients were retrospectively investigated in this study. An image intensity-based B-spline registration algorithm was used for deformable image registration (DIR) of weekly CBCT images to a reference image. The resultant displacement vector fields were employed to map the doses calculated on weekly images to the reference image. The concept of energy conservation was introduced as a criterion to evaluate the accuracy of the dose mapping operations. A finite element method (FEM)-based mechanical model was implemented to improve the performance of the B-Spline-based registration algorithm in regions involving tumor regression. For the six patients, deformed tumor volumes changed by 21.2±15.0% and 4.1±3.7% on average for the B-Spline and the FEM-based registrations performed from fraction 1 to fraction 21, respectively. The energy deposited in the gross tumor volume (GTV) was 0.66 Joules (J) per fraction on average. The energy derived from the fractional dose reconstructed by the B-spline and FEM-based DIR algorithms in the deformed GTV’s was 0.51 J and 0.64 J, respectively. Based on landmark comparisons for the 6 patients, mean error for the FEM-based DIR algorithm was 2.5±1.9 mm. The cross-correlation coefficient between the landmark-measured displacement error and the loss of radiation energy was −0.16 for the FEM-based algorithm. To avoid uncertainties in measuring distorted landmarks, the B-Spline-based registrations were compared to the FEM registrations, and their displacement differences equal 4.2±4.7 mm on average. The displacement differences were correlated to their relative loss of radiation energy with a cross-correlation coefficient equal to 0.68. Based on the principle of energy conservation, the FEM-based mechanical model has a better performance than the B-Spline-based DIR algorithm. It is recommended that the principle of energy conservation be incorporated into a comprehensive QA protocol for adaptive radiotherapy.

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Dose Escalation for Locally Advanced Lung Cancer Using Adaptive Radiation Therapy With Simultaneous Integrated Volume-Adapted Boost

Cited by 35 publications

References 16 publications

Benefits of adaptive radiation therapy in lung cancer as a function of replanning frequency

Benefits of adaptive radiation therapy in lung cancer as a function of replanning frequency

Recent Advances and Challenges in Adaptive Radiotherapy for Patients with Locally Advanced NSCLC

Adaptive radiotherapy for NSCLC patients: utilizing the principle of energy conservation to evaluate dose mapping operations

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