Lung sparing and dose escalation in a robust‐inspired IMRT planning method for lung radiotherapy that accounts for intrafraction motion

McCann, Claire; Purdie, Thomas G.; Hope, Andrew; Bezjak, Andrea; Bissonnette, Jean‐Pierre

doi:10.1118/1.4805101

Cited by 13 publications

(9 citation statements)

References 43 publications

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“…In this study, each GTV was provided with a 5 mm PTV expansion to account for slight changes in tumor motion and daily setup uncertainties as documented by Ruben et al9 Work by McCann66 and Chan51 have shown that such uncertainties can be accounted for with reduced tissue doses by escalating dose to the edges of the GTV. Therefore, a potentially ideal solution for future investigation is the optimization across the 4DCT dataset with intentional dose escalation at the maximum extent of travel.…”

Section: Discussionmentioning

confidence: 99%

Robust optimization of VMAT for lung cancer: Dosimetric implications of motion compensation techniques

Archibald-Heeren

Byrne

et al. 2017

J Applied Clin Med Phys

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In inverse planning of lung radiotherapy, techniques are required to ensure dose coverage of target disease in the presence of tumor motion as a result of respiration. A range of published techniques for mitigating motion effects were compared for dose stability across 5 breath cycles of ±2 cm. Techniques included planning target volume (PTV) expansions, internal target volumes with (OITV) and without tissue override (ITV), average dataset scans (ADS), and mini‐max robust optimization. Volumetric arc therapy plans were created on a thorax phantom and verified with chamber and film measurements. Dose stability was compared by DVH analysis in calculations across all geometries. The lung override technique resulted in a substantial lack of dose coverage (−10%) to the tumor in the presence of large motion. PTV, ITV and ADS techniques resulted in substantial (up to 25%) maximum dose increases where solid tissue travelled into low density optimized regions. The results highlight the need for care in optimization of highly heterogeneous where density variations may occur with motion. Robust optimization was shown to provide greater stability in both maximum (<3%) and minimum dose variations (<2%) over all other techniques.

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Section: Discussionmentioning

confidence: 99%

Robust optimization of VMAT for lung cancer: Dosimetric implications of motion compensation techniques

Archibald-Heeren

Byrne

et al. 2017

J Applied Clin Med Phys

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“…An offline- re-planning strategy was presented by Bratengeier et al The technique adapts step and shoot intensity modulated radiotherapy plans by modifying only the segment shapes and preserving the monitor units [ 18 , 19 ]. Another approach would be to generate motion robust treatment plans that are robust against interfraction and intrafraction motion [ 20 , 21 ]. Online workflows have increased with the availability of in-room imaging systems like CT or MRI.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of a software module for adaptive treatment planning and re-irradiation

et al. 2017

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BackgroundThe aim of this work is to validate the Dynamic Planning Module in terms of usability and acceptance in the treatment planning workflow.MethodsThe Dynamic Planning Module was used for decision making whether a plan adaptation was necessary within one course of radiation therapy. The Module was also used for patients scheduled for re-irradiation to estimate the dose in the pretreated region and calculate the accumulated dose to critical organs at risk. During one year, 370 patients were scheduled for plan adaptation or re-irradiation. All patient cases were classified according to their treated body region. For a sub-group of 20 patients treated with RT for lung cancer, the dosimetric effect of plan adaptation during the main treatment course was evaluated in detail. Changes in tumor volume, frequency of re-planning and the time interval between treatment start and plan adaptation were assessed.ResultsThe Dynamic Planning Tool was used in 20% of treated patients per year for both approaches nearly equally (42% plan adaptation and 58% re-irradiation). Most cases were assessed for the thoracic body region (51%) followed by pelvis (21%) and head and neck cases (10%). The sub-group evaluation showed that unintended plan adaptation was performed in 38% of the scheduled cases. A median time span between first day of treatment and necessity of adaptation of 17 days (range 4–35 days) was observed. PTV changed by 12 ± 12% on average (maximum change 42%). PTV decreased in 18 of 20 cases due to tumor shrinkage and increased in 2 of 20 cases. Re-planning resulted in a reduction of the mean lung dose of the ipsilateral side in 15 of 20 cases.ConclusionThe experience of one year showed high acceptance of the Dynamic Planning Module in our department for both physicians and medical physicists. The re-planning can potentially reduce the accumulated dose to the organs at risk and ensure a better target volume coverage. In the re-irradiation situation, the Dynamic Planning Tool was used to consider the pretreatment dose, to adapt the actual treatment schema more specifically and to review the accumulated dose.

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“…Comments [49,50,51,52,53,54,55,56,57,58,59,60,61] Dose accumulation methodology [62,53,63,64,65,66,67,68,69,70,71,72,73,74] Intra-fraction accumulation [75,76,77,78,70,79,80,81,82,83,84,85,86,87,83,88,89,90] Interplay effect [66,91,92,93,94,95,…”

Section: Refmentioning

confidence: 99%

Deformable image registration applied to lung SBRT: Usefulness and limitations

et al. 2017

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Radiation therapy (RT) of the lung requires deformation analysis. Deformable image registration (DIR) is the fundamental method to quantify deformations for various applications: motion compensation, contour propagation, dose accumulation, etc. DIR is therefore unavoidable in lung RT. DIR algorithms have been studied for decades and are now available both within commercial and academic packages. However, they are complex and have limitations that every user must be aware of before clinical implementation. In this paper, the main applications of DIR for lung RT with their associated uncertainties and their limitations are reviewed.

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Lung sparing and dose escalation in a robust‐inspired IMRT planning method for lung radiotherapy that accounts for intrafraction motion

Cited by 13 publications

References 43 publications

Robust optimization of VMAT for lung cancer: Dosimetric implications of motion compensation techniques

Robust optimization of VMAT for lung cancer: Dosimetric implications of motion compensation techniques

Evaluation of a software module for adaptive treatment planning and re-irradiation

Deformable image registration applied to lung SBRT: Usefulness and limitations

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