DVH 5161 PDF

OR, odds ratio; CI, confidence interval. These auto-delineated contours for the entire cohort were then reviewed and modified individually by hand after auto-segmentation had been completed to maintain consistency in for all 90 patients. This was corrected withminor modifications for each individual to ensure consistency. Bar graphs representing the percent risk for brachial plexopathy according to a cutoff median dose of 69 Gy to the entire brachial plexus panel A and a 75 Gy dose cutoff to 2 cm 3 of the brachial plexus panel B.

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Zulule The multi-atlas segmentation technique we used has the potential to reduce inter-subject, inter-observer, or even intra-observer variability in contouring the brachial plexus. Finally, because brachial plexopathy is relatively rare, the number of events in our study was low, which complicates our ability to generalize our defined dose limits to a larger population of patients with lung cancer. In this study we found that plexopathy before treatment was also associated with greater risk of toxicity after treatment.

Tel ; fax ; gro. Tolerance of normal tissue to therapeutic irradiation. Significant effect of adjuvant chemotherapy on survival in locally advanced non-small-cell lung carcinoma. Only minor modifications were made mostly as a result of arm position for these structures. Factors assessed in this manner include patient age at treatment, body mass index, smoking pack-years, median dose to the brachial plexus and maximum dose to 0.

A Axial CT dvj delineating the brachial plexus based on physician consensus green and computer-generated contours red. Also, changes in arm position can the visibility of the brachial plexus and can contribute to inaccuracies in deformable image registration. As a service to our customers we are providing this early version of the manuscript. CA Cancer J Clin.

Evaluation of Brachial Plexus Dose The Pinnacle planning system was used to calculate the dose to the brachial plexus using the original treatment plan. Lung cancer is the leading cause of cancer-related death worldwide, with approximately 1. The two curves were nearly superimposable. Patients with brachial plexopathy before treatment due to tumor invasion or surgical intervention were considered to have plexopathy after radiation treatment only if the plexopathy had cleared and then returned without evidence of new tumor impingement.

The resultant displacement vector fields characterizing the individual registrations were then used to deform the atlas brachial plexus contours to obtain 10 individual segmentations for each patient. Ten sets of atlas patients were registered to the new patient using deformable image registration DIR and the deformed atlas contours were fused to produce the final auto-segmented brachial plexus contours for the new patient. Statistical tests were based on a two-sided significance level.

At present, the maximum tolerated radiation dose for the brachial plexus remains a matter of debate. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Our study had several limitations. Brachial plexopathy was documented according to the Common Terminology Criteria for Adverse Events v4. This work was made possible through the of the family of M. Complication without a cure. The contours were drawn jointly by two thoracic radiation oncologists and one thoracic radiologist.

Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Journal of Clinical Oncology. When patients were treated with proton therapy using Varian Eclipse treatment planning, DICOM-RT dose plans were first exported from Eclipse planning system and then converted and imported into Pinnacle planning system for dose calculation.

Contouring the brachial plexus on CT scans continues to be challenging. This may prove to be problematic for complying with dose constraints to structures like the brachial plexus. Next we plan to validate these dose constraints in an ongoing randomized phase III trial looking at dose escalation for lung cancer. Conclusions For lung cancers near the apical region, brachial plexopathy is a major concern for high-dose radiation therapy. Auto-segmentation using deformable image registration followed by modification was found to be accurate for the majority of the cases, with only slight modification needed, mostly based on aberrant arm position.

Also, the borders of the brachial plexus, unlike those of other organs can be difficult to define. However, with current trials evaluating 74 Gy, the dose constraints for the brachial plexus need to be revisited, particularly because most of the literature on brachial plexus toxicity comes from studies of head and neck or breast cancer.

We also evaluated the contribution of other factors, such as having plexopathy before radiation, receipt of concurrent chemotherapy, and receipt of proton versus photon therapy, to the risk of developing brachial plexopathy.

We developed a computer-assisted image segmentation method which allowed us to rapidly and consistently contour the brachial plexus and establish the dose limits to minimize the risk of brachial plexopathy. To save time and improve the consistency of contouring, we applied a new multi-atlas segmentation method to automatically delineate brachial plexus contours as follows.

The purpose of this study was to identify a threshold radiation dose at which plexopathy becomes evident when that radiation is delivered using xvh techniques to tumors in the superior sulcus, upper mediastinum, or supraclavicular regions. For these reasons, estimates of smaller point doses may not have been accurate enough to predict the development of plexopathy. The underlying mechanismis thought to be due to demyelination leading to axon loss [ 9 ].

DVH -M Where no foramen was present, only the regions between the scalene muscles were contoured. J Natl Cancer Inst. Radiation-induced brachial plexopathy and hypofractionated regimens in adjuvant irradiation of patients with breast cancer—a review. Deformable Image Registration To save time and improve the consistency of contouring, we applied a new multi-atlas segmentation method to automatically delineate plexus contours as follows.

Development and validation of a standardized method for contouring the brachial plexus: Schematic diagram for auto-contouring the brachial plexus using multiple atlases. However, radiation doses that magnitude often result in local failure, which itself cancause brachial plexopathy. Gender, concurrent chemoradiation, and the presence of diabetes were not associated with risk of brachial plexopathy Table 2.

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Zulule The multi-atlas segmentation technique we used has the potential to reduce inter-subject, inter-observer, or even intra-observer variability in contouring the brachial plexus. Finally, because brachial plexopathy is relatively rare, the number of events in our study was low, which complicates our ability to generalize our defined dose limits to a larger population of patients with lung cancer. In this study we found that plexopathy before treatment was also associated with greater risk of toxicity after treatment. Tel ; fax ; gro.

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Tajas These 10 images were then incorporated in the deformable registry program. Bar graphs representing the percent risk for brachial plexopathy according to a cutoff median dose of 69 Gy to the rvh brachial plexus panel A and a 75 Gy dose cutoff to 2 cm 3 of the brachial plexus panel B. Also, changes in arm can affect the visibility of the brachial plexus and can contribute to inaccuracies in deformable image registration. DVH -M The median dose to the tumor was 70 Gy range Development and validation of a standardized method for contouring the brachial plexus: Validation of Deformable Image Registration Auto-segmentation using deformable image registration followed by modification was found to be accurate for the majority of the cases, with only slight modification needed, mostly based on aberrant arm position.

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DVH 5161 PDF

Tataur Open in a separate window. We also evaluated the contribution of other factors, such as having plexopathy before radiation, receipt of concurrent chemotherapy, and receipt of proton versus photon therapy, to the risk of developing brachial plexopathy. Also, the borders of the brachial plexus, unlike those of other organs can be difficult to define. It is well known that peripheral nerves are sensitive to recurrent episodes of trauma, whether from tumor invasion or from surgical intervention [ ]; multiple traumas might be expected to reduce the threshold for development of symptoms. The contours created by the image registration provided dvhh good approximate location of the brachial plexus.

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