Dose Constraints to Prevent Radiation-Induced Brachial Plexopathy in Patients Treated for Lung Cancer

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. In this retrospective analysis, we compared dose-volume histogram information with the incidence of plexopathy to establish the maximum tolerated dose to the brachial plexus. Methods and Materials We identified 90 patients with NSCLC treated with definitive chemoradiation from March 2007 through September 2010 who had received>55 Gy to the brachial plexus. We used a multi-atlas segmentation method combined with deformable image registration to delineate the brachial plexuson the original planning CT scans and scoredplexopathy according to the Common Terminology Criteria for Adverse Events v4.03. Results The median radiation dose to the brachial plexus was 70 Gy (range 56-87.5 Gy, 1.5-2.5 Gy/fraction). At a median follow-up time of 14.0 months, 14 patients had had brachial plexopathy (16%) (8 [9%] grade 1 and 6 [7%] grade ≥2); median time to symptom onset was 6.5 months (range 1.4-37.4 months). On multivariate analysis, receipt of median brachial plexus dose >69 Gy(odds ratio [OR] 10.091, 95% confidence interval [CI] 1.512-67.331, P=0.005), maximum dose >75 Gy to 2 cm3 of the brachial plexus(OR 4.909, 95% CI 0.966-24.952, P=0.038), and the presence of plexopathy before irradiation(OR 4.722, 95% CI 1.267-17.606, P=0.021) were independent predictors of brachial plexopathy. Conclusions For lung cancers near the apical region, brachial plexopathy is a major concern for high-dose radiation therapy. 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. Our results could be used as a guideline in future prospective trialswithhigh dose radiation therapy for unresectable lung cancer.

Brachial Plexus Dose Tolerance in Head-and-Neck Cancer Patients Treated With Sequential Intensity Modulated Radiation Therapy

“…It has been suggested that a range exists from a two-fold effect to higher [12,13]. More recently dose constraints from Amini et al [14] showed that patients treated for superior sulcus lung cancers with definitive CRT require that a median dose to the BP be kept below 69Gy and the maximum dose to 2 cc below 75Gy to prevent brachial plexopathy. We found no significant difference in the risk of brachial plexopathy for patients treated with or without CRT although most of our patients were treated with CRT.…”

Constraining the brachial plexus does not compromise regional control in oropharyngeal carcinoma

“…The time to the appearance of symptoms may vary significantly. Recent modern studies have reported median times to onset of symptoms ranging from 6.5 months to 4 years from the completion of radiotherapy and ranges of 1.4 months to 26 years [2,3]. Once they develop, there may be a gradual evolution of symptoms or a more rapid progression with time, which may on occasion culminate in complete loss of function of the affected arm [1,4].…”

“…Treatment options for these patients remain inadequate, and prognosis is poor. Brachial plexopathy has been associated with greater cumulative radiation dose to the brachial plexus (BP), radiotherapy fraction size, maximum dose, as well as the addition of chemotherapy and neck dissection [1,2,4-6]. One group recently used a validated symptom questionnaire in order to screen a large head-and-neck cancer population who had undergone radiation therapy.…”

Constraining the Brachial Plexus Does Not Compromise Regional Control in Oropharyngeal Carcinoma

“…The time to the appearance of symptoms may vary significantly. Recent modern studies have reported median times to onset of symptoms ranging from 6.5 months to 4 years from the completion of radiotherapy and ranges of 1.4 months to 26 years [2,3]. Once they develop, there may be a gradual evolution of symptoms or a more rapid progression with time, which may on occasion culminate in complete loss of function of the affected arm [1,4].…”

“…Treatment options for these patients remain inadequate, and prognosis is poor. Brachial plexopathy has been associated with greater cumulative radiation dose to the brachial plexus (BP), radiotherapy fraction size, maximum dose, as well as the addition of chemotherapy and neck dissection [1,2,[4][5][6]. One group recently used a validated symptom questionnaire in order to screen a large head-and-neck cancer population who had undergone radiation therapy.…”