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.
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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. As improvements in surgical and radiation techniques and chemotherapy regimens lead to longer survival for patients with lung cancer, the need to monitor toxicity and adapt our practice accordingly becomes ever more imperative.
III, IV and recurrent. 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. 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.
B Digitally-reconstructed radiographs DRR showing manual contours green and computer-generated contours red. Brachial plexopathy was documented according to the Common Terminology Criteria for Adverse Events v4. This patient later developed grade 2 toxicity. The median radiation dose to the brachial plexus was 70 Gy range Additional inclusion criteria were having at least 4 months of follow-up and having had either photon or proton therapy with 3D conformal or intensity-modulated radiation treatment planning, with or without concurrent chemotherapy.
Abstract Purpose As the recommended radiation dose for non-small cell lung cancer NSCLC increases, meeting dose constraints for critical structures like the brachial plexus becomes increasingly challenging, particularly for tumors in the superior sulcus.
For lung cancers near the apical region, brachial plexopathy is a major concern for high-dose radiation therapy. The potential benefit of tumor control must be balanced against the risk of treatment-related side effects on a case-by-case basis. Please refer to the text for details. Conclusions For lung cancers near the apical region, brachial plexopathy is a major concern for high-dose radiation therapy. The two curves were nearly superimposable.
Also, changes in arm position can affect the visibility of the brachial plexus and can contribute to inaccuracies in deformable image registration. The vdh of this study was to identify a threshold radiation dose at which plexopathy becomes evident when that radiation is delivered using modern-day techniques to tumors in the superior sulcus, upper mediastinum, or supraclavicular regions. The tolerated dose to the plexus continues to be debated; we have found this structure to be a dose-limiting factor in our phase III randomized comparison of protons versus photons for unresectable NSCLC.
C DRR showing patient with a superior sulcus tumor with contours of the brachial plexus generated by deformable image registration followed by manual Other significant risk factors were having plexopathy before treatment OR 4. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. P values of 0. Our findings here, focusing specifically on patients treated for lung cancer, indicate that the median dose to the brachial plexus should be kept below 69 Gy, and the maximum dose to 2 cm 3 below 75 Gy,for patients with NSCLC.
Arya AminiB. To save time and improve the consistency of , we applied a new multi-atlas segmentation method to automatically delineate brachial plexus contours as follows. We identified C5 through T1 roots, which served as the medial borders of the brachial plexus; the plexus was contoured from medial to lateral using the scalene muscles as landmarks[ 11 ]. 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.
The median time to symptom onset was 6. The median maximum doses to 0. CA Cancer J Clin. Ten sets of atlas patients were registered to the new patient using deformable image registration DIR and the fvh atlas contours were fused to produce the final auto-segmented brachial plexus contours for the new patient.
See other articles in PMC that cite the published article. Development and validation of a standardized method for contouring the brachial plexus: Results The median radiation dose to the brachial plexus was 70 Gy range In this study we found that plexopathy before treatment was also associated with greater risk of toxicity after treatment. Journal of Clinical Oncology. Evaluation of Brachial Plexus Dose The Pinnacle planning system was used to calculate the dose to the brachial plexus using the original treatment plan.
Our results could be used as a guideline in future prospective trialswithhigh dose radiation therapy for unresectable lung cancer. For these reasons, estimates of smaller point dvj may not have been accurate enough to predict the development of plexopathy. Complication without a cure. Finally, the Vvh Truth and Performance Level Estimation Evh algorithm [ 14 ] was used to combine these 10 individual segmentations to produce a single fused contour, which was considered the best statistical estimation of the true segmentation from multiple measurements.
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. Schematic diagram for auto-contouring the brachial plexus using multiple atlases.
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Meztijar Patients were retrospectively identified by searching an institutional database of patients treated with radiation for lung cancer at MD Anderson Cancer Center between March and September To reduce variability in our contouring of the brachial plexus, we followed guidelines based on easily delineated structures such as the sternocleidomastoid and scalene muscles and bony landmarks. A prospective randomized study of various irradiation doses and fractionation schedules in the treatment of inoperable non-oat-cell carcinoma of the lung. Among patients identified as having unresectable NSCLC treated with definitive chemoradiation, 90 had superior sulcus tumors or tumors involving the upper mediastinum or supraclavicular region and had received a dose of at least 55 Gy to 0. Interestingly, we found that doses to 0. Even with the differences in anatomy and positioning among patients, we noticed excellent correlation between the STAPLE fused contours and the manually generated contours, suggesting that STAPLE fusion of multiple individual segmentations can reduce variability and produce accurate contours. Treatment plans from those patients were de-archived from the tape backup system and restored into a research Pinnacle planning system Philips Healthcare.
Elektroměr DVH 5161-M, přímé měření 10-100A, 3 fáze, ověřený, CZ cejch
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. Also, changes in arm position can affect the visibility of the brachial plexus and can contribute to inaccuracies in deformable image registration.