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Evaluating a Nomogram for the Development of Radiation Pneumonitis in Locally Advanced Non-Small Cell Lung Cancer Treated With 3D and Intensity Modulated Radiation Therapy
Volume 90 Number 1S Supplement 2014 radiosurgery or Linac-based coplanar IMRT or VMAT treatment plans. Median follow-up imaging was 14 months. The presence or absence of fracture was identified from the most recent CT scan then compared to pretreatment and follow-up scans. Results: Of 236 patients reviewed 27 had thoracic vertebral compression fractures. Ten of the 27 patients developed fractures after radiation therapy and 7 were at the same vertebral level as the treated lesion. Treatment doses for these patients ranged from 20/1, 25/1, 30/1, 50/4, and 54 Gy/3 fractions. Fractures occurred between 7 and 28 months after SABR in the 7 patients. Two of the 7 patients had pre-existing thoracic fractures and 2 of the patients developed at least one fracture during the follow-up period at a vertebral level that did not receive radiation dose. Two of the 7 patients had rib fractures attributed to radiation dose. There were a total of 8 fractures as one patient had 3 lesions treated and 2 different vertebral levels affected. Six of the 7 patients were women and ages ranged from 64-89. CT scans revealed diffuse osteopenia in each of the patients. Four of the PTVs were 6-10 cm from the affected vertebral body and the other 3 PTVs abutted the affected vertebral body. Conclusions: Vertebral fractures after SABR to cancers in the lung are infrequent but may be associated with radiation dose. Patients at greatest risk appear to be postmenopausal women with diffuse osteopenia. With increased numbers and dosimetric evaluation we may soon be able to better define discrete risks. Understanding these risks and limiting vertebral body dose in high-risk patients could help avoid potentially severe fractures. Author Disclosure: T.A. Aguilera: None. N. Trakul: None. D. Shultz: None. P.G. Maxim: E. Research Grant; Varian, RaySearch. F. Honoraria; Varian. M. Diehn: E. Research Grant; Varian. B.W. Loo: E. Research Grant; Varian, RaySearch. F. Honoraria; Varian.
1009 Cardiac Events After Treatment With High-Dose Radiation Therapy +/e Chemotherapy for Non-Small Cell Lung Cancer L. Tang,1,2 A. Liu,3 D.R. Gomez,1 Q. Nguyen,1 T. Xu,1 R.U. Komaki,1 and Z. Liao1; 1University of Texas MD Anderson Cancer Center, Houston, TX, 2Sun Yat-sen University Cancer Center, Guangzhou, China, 3The Second Affiliated Hospital, Nanchang University, Nanchang, China Purpose/Objective(s): Cardiac events after high-dose radiation therapy (RT) for non-small cell lung cancer (NSCLC) have not been reported comprehensively. We performed a detailed analysis of cardiac toxicity that occurred in a cohort of patients treated with definitive doses of RT in this context. Materials/Methods: This study included 303 NSCLC patients who received RT (dose 60 Gy) from April 1, 2004 through May 31, 2010 at a single institution. The median radiation prescription dose was 70 Gy (range, 60-87.5 Gy). The median value of the mean heart dose (MHD) was 11.4 Gy (range, 0-52.4 Gy). Thirty-two percent of patients (n Z 96) received induction chemotherapy, 84.8% (n Z 257) received concurrent chemotherapy, and 20.8% (n Z 63) received adjuvant chemotherapy. Preexisting cardiac conditions included myocardial ischemia in 15.8% of patients (n Z 48), arrhythmia in 9.9% (n Z 30), hypertension in 49.5% (n Z 150), and diabetes mellitus in 13.2% (n Z 40). Cardiac toxicity was defined as having any previously undocumented cardiac event occurring after the start of radiation therapy, and was classified into five categories: myocardium ischemia, pericarditis, arrhythmia, heart failure, and valve abnormalities, each scored according to the CTCAE v4.0 system. Patients that were diagnosed with new cardiac events after RT were compared with those that were not using the chi-squared test. Then, the cumulative incidence of each category of cardiac events according to different MHD was compared using the log-rank test. Results: Fifty-three percent of patients (n Z 161) in the entire patient cohort were found to have a new cardiac diagnosis after RT. The incidence of new-onset myocardial ischemia, pericarditis, arrhythmia, heart failure and valve abnormalities were 5.6%, 39.3%, 11.9%, 4.0%, and 17.2%, respectively. The median time to develop grade 2 or above myocardial ischemia, pericarditis, arrhythmia, heart failure, and valve abnormalities
Digital Poster Discussion Abstracts S161 was 8.8, 8.6, 7.7, 4.8, and 9.6 months, respectively. Patients with new cardiac diagnoses after RT did not differ from those without new cardiac events with respect to age, sex, stage (I-II vs III-IV vs recurrence), laterality of tumor (right vs left), smoking, alcohol history, prior cardiac disease, or RT technique (p > 0.05 for all). With regard to specific cardiac events, the use of concurrent chemotherapy and adjuvant chemotherapy (OR Z 2.31, 95% CI: 1.12-4.74, p Z 0.02; OR Z 2.14, 95% CI: 1.223.75, p Z 0.01) was associated with pericarditis, while a MHD of 22.6 Gy or higher was correlated with the cumulative incidence of post-RT myocardial ischemia (p Z 0.02). Conclusions: The incidence of developing cardiac events after high-dose RT for NSCLC is approximately 50%, with the most common events being myocardial ischemia, pericarditis, and arrhythmia. Treatment-specific correlations with specific event types may be due to differing mechanisms of each of these modalities. Author Disclosure: L. Tang: None. A. Liu: None. D.R. Gomez: None. Q. Nguyen: None. T. Xu: None. R.U. Komaki: None. Z. Liao: None.
1010 Evaluating a Nomogram for the Development of Radiation Pneumonitis in Locally Advanced Non-Small Cell Lung Cancer Treated With 3D and Intensity Modulated Radiation Therapy S. Rehman,1 C.K. Speirs,1 A. Molotievschi,2 D. Mullen,1 S. Fergus,1 T.A. DeWees,1 M.A. Velez,1 J.D. Bradley,1 and C.G. Robinson1; 1 Washington University, St. Louis, MO, 2Barretos Cancer Hospital, Barretos, Brazil Purpose/Objective(s): Radiation pneumonitis (RP) is a dose-limiting late toxicity in thoracic irradiation. A previously published nomogram, which incorporates total lung mean dose and tumor superior-inferior lung location, developed at our institution has been developed to predict the risk of RP for patients treated with definitive 3D conformal radiation therapy (3DCRT) for locally advanced non-small cell lung cancer (NSCLC) prior to 2001. In this study, we tested the nomogram on a more modern cohort of patients, including patients treated with intensity modulated radiation therapy (IMRT). Risk factors for developing RP were also evaluated. Materials/Methods: Patients treated using either 3DCRT or IMRT for locally advanced NSCLC from 2001 to 2012 were queried. Clinical, tumor, and dosimetric information were collected. Log-rank test was used to determine predictors of grade 2 or higher RP, based on Common Terminology Criteria for Adverse Events version 4.0. RP risk was determined based on a previously published nomogram predicting for RP. Spearman’s rank correlation was performed based on the calculated risk of RP versus the actual rate of RP. Results: The entire cohort included 340 patients, including 277 (81%) patients treated with 3DCRT and 63 (19%) patients treated with IMRT. Median age of patients was 65 years. The raw rate of grade 2 or higher RP was 35% (35% for patients treated with 3DCRT; 32% for patients treated with IMRT). For the entire cohort, on univariate analysis, use of adjuvant chemotherapy, former smoking status, heart mean dose, heart volume receiving 5-55 Gray (Gy), total lung volume minus planning target volume receiving 35-50 Gy, and RP risk nomogram score were predictive of increased risk of RP; current smoking was protective of RP. On multivariate analysis, heart volume receiving 35 Gy [odds ratio (OR): 1.018, 95% confidence interval (CI): 1.004-1.033, p Z 0.012] was predictive for increased risk of RP and current smoking (OR: 0.369, 95% CI: 0.1920.709, p Z 0.0008) was predictive for decreased risk of RP. Spearman’s rank correlation for RP risk nomogram score showed r Z 0.208 (p Z 0.001) for the entire cohort. For patients treated with 3DCRT, r Z 0.225 (p Z 0.0014); for patients treated with IMRT, r Z 0.161 (p Z 0.26). Conclusions: The dose to the heart is predictive for the risk of RP. The previously published nomogram for predicting RP in locally advanced NSCLC is validated for patients treated with 3DCRT, although it loses predictive power compared to the previously published data, which had r Z 0.28. For patients treated with IMRT, the nomogram was not validated and future studies will help develop a new model for this cohort of patients, particularly evaluating heart dosimetric information.
S162
International Journal of Radiation Oncology Biology Physics
Author Disclosure: S. Rehman: None. C.K. Speirs: None. A. Molotievschi: None. D. Mullen: None. S. Fergus: None. T.A. DeWees: None. M.A. Velez: None. J.D. Bradley: None. C.G. Robinson: None.
body radiation therapy (SBRT) face a similar increased risk. This study aims to address toxicity and survival achieved with SBRT in the elderly compared to younger patients treated at the same institution. Materials/Methods: Records of patients diagnosed with T1-3N0M0 NSCLC treated with SBRT between Sep 2007 and Aug 2013 were reviewed. SBRT was delivered in 3-5 fractions to 40-60 Gy, with a vast majority of patients receiving 54 Gy in 3 fractions. Patients were divided into two cohorts, aged 75 and < 75. Kaplan-Meier and Cox proportional hazard analyses were used for univariate and multivariate analyses of survival, respectively. Chi-square and logistic regression analyses were used for univariate and multivariate toxicity assessment, respectively. We compared overall survival (OS), local recurrence-free survival (LRFS), and distant recurrence-free survival (DRFS) between cohorts. Results: Two hundred fifty-three patients were identified. Of these, 127 were 75 and 126 were < 75. Median follow-up was 24.9 mos. There were no differences in gender, ECOG performance status, smoking status, clinical vs pathological diagnosis of NSCLC, histology (adenoca vs all others), T-stage (T1 v T2-3), peripheral vs central tumor, BED, or number of targets between the two groups (all p > 0.05). There was a trend toward less frequent mediastinal staging in the elderly (25.2% vs 34.9%, p Z 0.10). There was no difference between patients 75 vs < 75 in 2-year OS (48.8% vs 60.4%, p Z 0.95) or LRFS (86.1% vs 88.4%, p Z 0.97). There was a statistically significant difference in 2-year DRFS (89.9% vs 74.9%, HR Z 0.44, p Z 0.02) favoring patients 75. On multivariate Cox proportional hazards analysis, age 75 remained associated with improved DRFS (HR Z 0.40, p Z 0.02). There was no difference in acute or late grade 2-3 toxicity for patients age 75 vs < 75. Common toxicities included fatigue, chest wall pain, and increased dyspnea/pneumonitis. Rate of grade 3 acute toxicity was 5.5% overall (4.7% age 75 vs 6.3% age < 75). Rate of grade 3 late toxicity was 4.0% overall (3.9% age 75 vs 4.0% age < 75). Most common acute and late grade 3 toxicity was increased dyspnea/pneumonitis (3.6% and 2.0%, respectively). Two patients had grade 4 acute, 1 had grade 4 late, and 1 had grade 5 late toxicity in the < 75 cohort, with no grade 4-5 toxicity in the 75 cohort. Conclusions: To our knowledge, this is the largest single institution study to date evaluating safety and efficacy of SBRT in an elderly population. In our series, elderly patients undergoing SBRT appear to have achieved similar outcomes and toxicity compared to younger patients. Author Disclosure: B.R. Mancini: None. H.S. Park: None. E. Harder: None. C.E. Rutter: None. C.D. Corso: None. R.H. Decker: None. Z.A. Husain: None.
1011 Decreased Risk of Radiation Pneumonitis With Coincident Concurrent Use of Angiotensin-Converting Enzyme Inhibitors in Patients Receiving Lung Stereotactic Body Radiation Therapy (SBRT) F. Alite,1 M. Surucu,1 I. Mescioglu,2 and M. Harkenrider1; 1Loyola University Medical Center, Maywood, IL, 2Lewis University, Romeoville, IL Purpose/Objective(s): Angiotensin-converting enzyme inhibitors (ACEi) have demonstrated a decreased rate of radiation-induced lung injury in animal models. RTOG undertook a phase 2 trial to test this effect which was closed early due to poor accrual. In this study we tested the role of ACE inhibitors in diminishing rates of symptomatic pneumonitis in the setting of stereotactic body radiation therapy to the lung. Materials/Methods: A retrospective review of patients treated with thoracic SBRT analyzing rates of incidental concurrent use of ACEi and development of symptomatic pneumonitis was performed. We analyzed 193 patients treated with Linac-based SBRT with 7-10 non-coplanar beams for primary, recurrent, and metastatic lung tumors. Patients were treated with doses of 40-60 Gy in 3-5 fractions from 2006 to 2013. Plans were evaluated to meet criteria for lung tolerance of total lung V20 less than 10%, total lung V12.5 less than 15%, total lung V5 of less than 37%, and mean lung dose of less than 20 Gy. We recorded symptomatic pneumonitis up to 6 months posttreatment based on Common Terminology Criteria for Adverse Events. Pre and posttreatment medication profiles were reviewed to document use of ACE inhibitors, angiotensin receptor blockers, bronchodilators, ASA, PDE5 inhibitors, nitrates, and endothelin receptor antagonists. A decision tree analysis was performed to investigate risk factors for development of symptomatic pneumonitis. Multiple variables including patient age, sex, KPS, clinical stage, tumor location, prescription dose, and concurrent use of 7 different bronchoactive medications were evaluated by the decision tree. Results: The majority (85%) of patients were treated with 50 Gy in 5 fractions, and 8% of patients with 60 Gy in 5 fraction. Twenty-three patients experienced grade 2 or higher pneumonitis, an absolute rate of 11.9%. Forty-eight patients (25%) were found to be on ACEi during delivery of SBRT. Only one patient on a concurrent ACEi experienced symptomatic pneumonitis. The rate of grade 2 or higher pneumonitis was significantly lower in patients prescribed an ACEi vs patients not on an ACEi (2% vs 15%, chi-square test p Z 0.01). Additionally, in a decision tree analysis accounting for the clinical/patient characteristics and medication profiles we can predict with 97% accuracy that patients on an ACEi will not experience symptomatic pneumonitis. Conclusions: ACE inhibitors appear to have efficacy in diminishing rates of symptomatic pneumonitis in the setting of lung stereotactic body radiation therapy, which was validated in a decision tree statistical analysis. Prospective analysis is needed to confirm these findings. Author Disclosure: F. Alite: None. M. Surucu: None. I. Mescioglu: None. M. Harkenrider: None.
1012 Elderly Patients Undergoing SBRT for Inoperable Early-Stage NSCLC Achieve Similar Outcomes to Younger Patients B.R. Mancini, H.S. Park, E. Harder, C.E. Rutter, C.D. Corso, R.H. Decker, and Z.A. Husain; Yale School of Medicine, Yale University, New Haven, CT Purpose/Objective(s): A recent publication demonstrated that lung resection in patients aged > 65 with early stage non-small cell lung cancer (NSCLC) was associated with perioperative complications in > 50% of cases. This was found to increase with age and was significantly higher for patients aged 75. It is unclear if older patients undergoing stereotactic
1013 Incidence of Mild Cognitive Impairment in Irradiated Brain Tumor Survivors E. Shaw,1 N. McKee,1 D. Case,1 J. Lawrence,1 G. Lesser,1 M. Naughton,1 A. Peiffer,1,2 M. Loghin,2,3 J. Giguere,3,4 V. Stieber,4 and S. Rapp1; 1Wake Forest School of Medicine, Winston-Salem, NC, 2University of Texas MD Anderson Cancer Center, Houston, TX, 3Cancer Center of the Carolinas, Seneca, SC, 4Forsyth Regional Cancer Center, Winston-Salem, NC Purpose/Objective(s): A single institution association criteria for Mild Cognitive Impairment (MCI) include: (1) a reported change in cognition, (2) impairment in > 1 cognitive domains, (3) preservation of functional independence, and (4) not demented. The purpose of this study was to determine the incidence of MCI in a cohort of irradiated brain tumor survivors. Materials/Methods: From 2/08-12/11, 198 adult primary/metastatic brain tumor and/or PCI survivors 6 months post partial or whole-brain radiation therapy ( 30 Gy) participated in a prospective clinical trial in which they were randomly assigned to receive 6 months of donepezil or placebo. Baseline self-reported cognitive symptoms were assessed with the FACTBrain; cognitive function was assessed with the Hopkins Verbal Learning Test-Revised modified, Rey-Osterreith Complex Figure, Trail Making Test, Digit Span, Controlled Oral Word Association, and Grooved Pegboard. The criteria for MCI could be determined in 197 of 198 patients. Change in cognition and preservation of functional independence were
1009 Cardiac Events After Treatment With High-Dose Radiation Therapy +/e Chemotherapy for Non-Small Cell Lung Cancer L. Tang,1,2 A. Liu,3 D.R. Gomez,1 Q. Nguyen,1 T. Xu,1 R.U. Komaki,1 and Z. Liao1; 1University of Texas MD Anderson Cancer Center, Houston, TX, 2Sun Yat-sen University Cancer Center, Guangzhou, China, 3The Second Affiliated Hospital, Nanchang University, Nanchang, China Purpose/Objective(s): Cardiac events after high-dose radiation therapy (RT) for non-small cell lung cancer (NSCLC) have not been reported comprehensively. We performed a detailed analysis of cardiac toxicity that occurred in a cohort of patients treated with definitive doses of RT in this context. Materials/Methods: This study included 303 NSCLC patients who received RT (dose 60 Gy) from April 1, 2004 through May 31, 2010 at a single institution. The median radiation prescription dose was 70 Gy (range, 60-87.5 Gy). The median value of the mean heart dose (MHD) was 11.4 Gy (range, 0-52.4 Gy). Thirty-two percent of patients (n Z 96) received induction chemotherapy, 84.8% (n Z 257) received concurrent chemotherapy, and 20.8% (n Z 63) received adjuvant chemotherapy. Preexisting cardiac conditions included myocardial ischemia in 15.8% of patients (n Z 48), arrhythmia in 9.9% (n Z 30), hypertension in 49.5% (n Z 150), and diabetes mellitus in 13.2% (n Z 40). Cardiac toxicity was defined as having any previously undocumented cardiac event occurring after the start of radiation therapy, and was classified into five categories: myocardium ischemia, pericarditis, arrhythmia, heart failure, and valve abnormalities, each scored according to the CTCAE v4.0 system. Patients that were diagnosed with new cardiac events after RT were compared with those that were not using the chi-squared test. Then, the cumulative incidence of each category of cardiac events according to different MHD was compared using the log-rank test. Results: Fifty-three percent of patients (n Z 161) in the entire patient cohort were found to have a new cardiac diagnosis after RT. The incidence of new-onset myocardial ischemia, pericarditis, arrhythmia, heart failure and valve abnormalities were 5.6%, 39.3%, 11.9%, 4.0%, and 17.2%, respectively. The median time to develop grade 2 or above myocardial ischemia, pericarditis, arrhythmia, heart failure, and valve abnormalities
Digital Poster Discussion Abstracts S161 was 8.8, 8.6, 7.7, 4.8, and 9.6 months, respectively. Patients with new cardiac diagnoses after RT did not differ from those without new cardiac events with respect to age, sex, stage (I-II vs III-IV vs recurrence), laterality of tumor (right vs left), smoking, alcohol history, prior cardiac disease, or RT technique (p > 0.05 for all). With regard to specific cardiac events, the use of concurrent chemotherapy and adjuvant chemotherapy (OR Z 2.31, 95% CI: 1.12-4.74, p Z 0.02; OR Z 2.14, 95% CI: 1.223.75, p Z 0.01) was associated with pericarditis, while a MHD of 22.6 Gy or higher was correlated with the cumulative incidence of post-RT myocardial ischemia (p Z 0.02). Conclusions: The incidence of developing cardiac events after high-dose RT for NSCLC is approximately 50%, with the most common events being myocardial ischemia, pericarditis, and arrhythmia. Treatment-specific correlations with specific event types may be due to differing mechanisms of each of these modalities. Author Disclosure: L. Tang: None. A. Liu: None. D.R. Gomez: None. Q. Nguyen: None. T. Xu: None. R.U. Komaki: None. Z. Liao: None.
1010 Evaluating a Nomogram for the Development of Radiation Pneumonitis in Locally Advanced Non-Small Cell Lung Cancer Treated With 3D and Intensity Modulated Radiation Therapy S. Rehman,1 C.K. Speirs,1 A. Molotievschi,2 D. Mullen,1 S. Fergus,1 T.A. DeWees,1 M.A. Velez,1 J.D. Bradley,1 and C.G. Robinson1; 1 Washington University, St. Louis, MO, 2Barretos Cancer Hospital, Barretos, Brazil Purpose/Objective(s): Radiation pneumonitis (RP) is a dose-limiting late toxicity in thoracic irradiation. A previously published nomogram, which incorporates total lung mean dose and tumor superior-inferior lung location, developed at our institution has been developed to predict the risk of RP for patients treated with definitive 3D conformal radiation therapy (3DCRT) for locally advanced non-small cell lung cancer (NSCLC) prior to 2001. In this study, we tested the nomogram on a more modern cohort of patients, including patients treated with intensity modulated radiation therapy (IMRT). Risk factors for developing RP were also evaluated. Materials/Methods: Patients treated using either 3DCRT or IMRT for locally advanced NSCLC from 2001 to 2012 were queried. Clinical, tumor, and dosimetric information were collected. Log-rank test was used to determine predictors of grade 2 or higher RP, based on Common Terminology Criteria for Adverse Events version 4.0. RP risk was determined based on a previously published nomogram predicting for RP. Spearman’s rank correlation was performed based on the calculated risk of RP versus the actual rate of RP. Results: The entire cohort included 340 patients, including 277 (81%) patients treated with 3DCRT and 63 (19%) patients treated with IMRT. Median age of patients was 65 years. The raw rate of grade 2 or higher RP was 35% (35% for patients treated with 3DCRT; 32% for patients treated with IMRT). For the entire cohort, on univariate analysis, use of adjuvant chemotherapy, former smoking status, heart mean dose, heart volume receiving 5-55 Gray (Gy), total lung volume minus planning target volume receiving 35-50 Gy, and RP risk nomogram score were predictive of increased risk of RP; current smoking was protective of RP. On multivariate analysis, heart volume receiving 35 Gy [odds ratio (OR): 1.018, 95% confidence interval (CI): 1.004-1.033, p Z 0.012] was predictive for increased risk of RP and current smoking (OR: 0.369, 95% CI: 0.1920.709, p Z 0.0008) was predictive for decreased risk of RP. Spearman’s rank correlation for RP risk nomogram score showed r Z 0.208 (p Z 0.001) for the entire cohort. For patients treated with 3DCRT, r Z 0.225 (p Z 0.0014); for patients treated with IMRT, r Z 0.161 (p Z 0.26). Conclusions: The dose to the heart is predictive for the risk of RP. The previously published nomogram for predicting RP in locally advanced NSCLC is validated for patients treated with 3DCRT, although it loses predictive power compared to the previously published data, which had r Z 0.28. For patients treated with IMRT, the nomogram was not validated and future studies will help develop a new model for this cohort of patients, particularly evaluating heart dosimetric information.
S162
International Journal of Radiation Oncology Biology Physics
Author Disclosure: S. Rehman: None. C.K. Speirs: None. A. Molotievschi: None. D. Mullen: None. S. Fergus: None. T.A. DeWees: None. M.A. Velez: None. J.D. Bradley: None. C.G. Robinson: None.
body radiation therapy (SBRT) face a similar increased risk. This study aims to address toxicity and survival achieved with SBRT in the elderly compared to younger patients treated at the same institution. Materials/Methods: Records of patients diagnosed with T1-3N0M0 NSCLC treated with SBRT between Sep 2007 and Aug 2013 were reviewed. SBRT was delivered in 3-5 fractions to 40-60 Gy, with a vast majority of patients receiving 54 Gy in 3 fractions. Patients were divided into two cohorts, aged 75 and < 75. Kaplan-Meier and Cox proportional hazard analyses were used for univariate and multivariate analyses of survival, respectively. Chi-square and logistic regression analyses were used for univariate and multivariate toxicity assessment, respectively. We compared overall survival (OS), local recurrence-free survival (LRFS), and distant recurrence-free survival (DRFS) between cohorts. Results: Two hundred fifty-three patients were identified. Of these, 127 were 75 and 126 were < 75. Median follow-up was 24.9 mos. There were no differences in gender, ECOG performance status, smoking status, clinical vs pathological diagnosis of NSCLC, histology (adenoca vs all others), T-stage (T1 v T2-3), peripheral vs central tumor, BED, or number of targets between the two groups (all p > 0.05). There was a trend toward less frequent mediastinal staging in the elderly (25.2% vs 34.9%, p Z 0.10). There was no difference between patients 75 vs < 75 in 2-year OS (48.8% vs 60.4%, p Z 0.95) or LRFS (86.1% vs 88.4%, p Z 0.97). There was a statistically significant difference in 2-year DRFS (89.9% vs 74.9%, HR Z 0.44, p Z 0.02) favoring patients 75. On multivariate Cox proportional hazards analysis, age 75 remained associated with improved DRFS (HR Z 0.40, p Z 0.02). There was no difference in acute or late grade 2-3 toxicity for patients age 75 vs < 75. Common toxicities included fatigue, chest wall pain, and increased dyspnea/pneumonitis. Rate of grade 3 acute toxicity was 5.5% overall (4.7% age 75 vs 6.3% age < 75). Rate of grade 3 late toxicity was 4.0% overall (3.9% age 75 vs 4.0% age < 75). Most common acute and late grade 3 toxicity was increased dyspnea/pneumonitis (3.6% and 2.0%, respectively). Two patients had grade 4 acute, 1 had grade 4 late, and 1 had grade 5 late toxicity in the < 75 cohort, with no grade 4-5 toxicity in the 75 cohort. Conclusions: To our knowledge, this is the largest single institution study to date evaluating safety and efficacy of SBRT in an elderly population. In our series, elderly patients undergoing SBRT appear to have achieved similar outcomes and toxicity compared to younger patients. Author Disclosure: B.R. Mancini: None. H.S. Park: None. E. Harder: None. C.E. Rutter: None. C.D. Corso: None. R.H. Decker: None. Z.A. Husain: None.
1011 Decreased Risk of Radiation Pneumonitis With Coincident Concurrent Use of Angiotensin-Converting Enzyme Inhibitors in Patients Receiving Lung Stereotactic Body Radiation Therapy (SBRT) F. Alite,1 M. Surucu,1 I. Mescioglu,2 and M. Harkenrider1; 1Loyola University Medical Center, Maywood, IL, 2Lewis University, Romeoville, IL Purpose/Objective(s): Angiotensin-converting enzyme inhibitors (ACEi) have demonstrated a decreased rate of radiation-induced lung injury in animal models. RTOG undertook a phase 2 trial to test this effect which was closed early due to poor accrual. In this study we tested the role of ACE inhibitors in diminishing rates of symptomatic pneumonitis in the setting of stereotactic body radiation therapy to the lung. Materials/Methods: A retrospective review of patients treated with thoracic SBRT analyzing rates of incidental concurrent use of ACEi and development of symptomatic pneumonitis was performed. We analyzed 193 patients treated with Linac-based SBRT with 7-10 non-coplanar beams for primary, recurrent, and metastatic lung tumors. Patients were treated with doses of 40-60 Gy in 3-5 fractions from 2006 to 2013. Plans were evaluated to meet criteria for lung tolerance of total lung V20 less than 10%, total lung V12.5 less than 15%, total lung V5 of less than 37%, and mean lung dose of less than 20 Gy. We recorded symptomatic pneumonitis up to 6 months posttreatment based on Common Terminology Criteria for Adverse Events. Pre and posttreatment medication profiles were reviewed to document use of ACE inhibitors, angiotensin receptor blockers, bronchodilators, ASA, PDE5 inhibitors, nitrates, and endothelin receptor antagonists. A decision tree analysis was performed to investigate risk factors for development of symptomatic pneumonitis. Multiple variables including patient age, sex, KPS, clinical stage, tumor location, prescription dose, and concurrent use of 7 different bronchoactive medications were evaluated by the decision tree. Results: The majority (85%) of patients were treated with 50 Gy in 5 fractions, and 8% of patients with 60 Gy in 5 fraction. Twenty-three patients experienced grade 2 or higher pneumonitis, an absolute rate of 11.9%. Forty-eight patients (25%) were found to be on ACEi during delivery of SBRT. Only one patient on a concurrent ACEi experienced symptomatic pneumonitis. The rate of grade 2 or higher pneumonitis was significantly lower in patients prescribed an ACEi vs patients not on an ACEi (2% vs 15%, chi-square test p Z 0.01). Additionally, in a decision tree analysis accounting for the clinical/patient characteristics and medication profiles we can predict with 97% accuracy that patients on an ACEi will not experience symptomatic pneumonitis. Conclusions: ACE inhibitors appear to have efficacy in diminishing rates of symptomatic pneumonitis in the setting of lung stereotactic body radiation therapy, which was validated in a decision tree statistical analysis. Prospective analysis is needed to confirm these findings. Author Disclosure: F. Alite: None. M. Surucu: None. I. Mescioglu: None. M. Harkenrider: None.
1012 Elderly Patients Undergoing SBRT for Inoperable Early-Stage NSCLC Achieve Similar Outcomes to Younger Patients B.R. Mancini, H.S. Park, E. Harder, C.E. Rutter, C.D. Corso, R.H. Decker, and Z.A. Husain; Yale School of Medicine, Yale University, New Haven, CT Purpose/Objective(s): A recent publication demonstrated that lung resection in patients aged > 65 with early stage non-small cell lung cancer (NSCLC) was associated with perioperative complications in > 50% of cases. This was found to increase with age and was significantly higher for patients aged 75. It is unclear if older patients undergoing stereotactic
1013 Incidence of Mild Cognitive Impairment in Irradiated Brain Tumor Survivors E. Shaw,1 N. McKee,1 D. Case,1 J. Lawrence,1 G. Lesser,1 M. Naughton,1 A. Peiffer,1,2 M. Loghin,2,3 J. Giguere,3,4 V. Stieber,4 and S. Rapp1; 1Wake Forest School of Medicine, Winston-Salem, NC, 2University of Texas MD Anderson Cancer Center, Houston, TX, 3Cancer Center of the Carolinas, Seneca, SC, 4Forsyth Regional Cancer Center, Winston-Salem, NC Purpose/Objective(s): A single institution association criteria for Mild Cognitive Impairment (MCI) include: (1) a reported change in cognition, (2) impairment in > 1 cognitive domains, (3) preservation of functional independence, and (4) not demented. The purpose of this study was to determine the incidence of MCI in a cohort of irradiated brain tumor survivors. Materials/Methods: From 2/08-12/11, 198 adult primary/metastatic brain tumor and/or PCI survivors 6 months post partial or whole-brain radiation therapy ( 30 Gy) participated in a prospective clinical trial in which they were randomly assigned to receive 6 months of donepezil or placebo. Baseline self-reported cognitive symptoms were assessed with the FACTBrain; cognitive function was assessed with the Hopkins Verbal Learning Test-Revised modified, Rey-Osterreith Complex Figure, Trail Making Test, Digit Span, Controlled Oral Word Association, and Grooved Pegboard. The criteria for MCI could be determined in 197 of 198 patients. Change in cognition and preservation of functional independence were