Risk Factors For Radiation Pneumonitis Research Articles

Risk of Pneumonitis After Stereotactic Body Radiation Therapy for Non-Small Cell Lung Cancer in Patients With Prior Anatomic Resection

Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) has emerged as a standard treatment option for early stage, medically inoperable non-small cell lung cancer (NSCLC). Dosimetric factors including lung volume receiving 20 Gy (V20) >10%and mean lung dose (MLD) >4 Gy are established risk factors for radiation pneumonitis (RP) following SBRT, but limited data evaluate the relative risk of RP in patients undergoing SBRT following prior anatomic lung resection (ALR). This study assessed the incidence of RP and all grade 2+ pulmonary toxicity in patients treated with SBRT for NSCLC following ALR and compare toxicity rates to patients without prior ALR. Materials/Methods: The medical records of 83 consecutive patients with T1-T3 NSCLC treated with 87 courses of SBRT for 93 lung tumors (16 central, 77 peripheral) between January 2007 and September 2013 were reviewed. Sixteen patients with a history of prior ALR were identified, including lobectomy (n Z 12), bilobectomy (nZ 1), and pneumonectomy (n Z 3), with 67 patients without history of prior ALD. The most commonly used fractionation regimen was 50Gy in 5 fractions. Toxicities were graded according to the Common Terminology Criteria for Adverse Events (CTCAE) v.4.0. Rates of grade 2+ RP and any grade 2+ pulmonary toxicity were compared between patients with and without prior ALR. Crude rates of RP and all grade 2+ pulmonary toxicity were compared using Fisher’s exact test. Actuarial estimates of freedom from RP (FFRP), in-lobe control (ILC), and overall survival (OS) were calculated with the Kaplan-Meier method and compared between cohorts via the log rank method. Results: At a median follow up of 11.9 months (range 1.2 to 81 months), 3 patients developed grade 2+ RP at a median of 4.0 months (range: 1.0-14.8 months). The crude rates of RP were 6.3% and 2.9% for patients with and without prior ALD, respectively (p>0.05). The 2 year Kaplan-Meier estimates of freedom from RP were 86% and 97% (p>0.05). Crude rates of all grade 2+ pulmonary toxicity were 11.8% and 2.9%, respectively, with associated 2 year estimates of 97% and 81%, respectively (p>0.05). The 2 cohorts were well matched by mean lung dose (4.67 Gy vs 4.15 Gy), lung V20 (5.16% vs 4.35%), mean PTV (30.63 cc vs 36.16 cc), and median prescribed dose (50 Gy vs 54) (p>0.05 for all). Conclusions: Observed rates of pulmonary toxicity were low among patients treated by SBRT after ALR. These data provide reassurances that SBRT can be performed safely for patients with prior ALR when conventional lung DVH constraints are utilized. Author Disclosure: J.T. Hayes: None. A.M. Chen: None. M.E. Daly: None.

A Retrospective Study of Risk Factors for Radiation Pneumonitis of Definitive Chemoradiotherapy for the Treatment of Locally Advanced Lung Cancer By Emphysema Quantification

ABSTRACT Aim: Radiation pneumonitis (RP) is one of the most crucial adverse events of definitive chemoradiotherapy for the treatment of locally advanced lung cancer. Although chronic obstructive pulmonary disease (COPD) is considered as one of the risk factors of RP, the relationship between RP and pulmonary emphysema (PE) that is a subtype of COPD is not clear. We examined the clinical backgrounds of patients experiencing RP due to concurrent chemodadiotherapy for the treatment of locally advanced lung cancer and evaluated risk factors. Methods: We retrospectively examined patients with locally advanced lung cancer who underwent definitive chemoradiotherapy between Janary 2010 and December 2012. For quantitative assessments of PE, percentage of low attenuation volumes (%LAV) and mean density (MD) were computationally calculated by using AZE Virtual place Fujin (Tokyo). Common Terminology Criteria for Adverse Events (CTCAE) v.4.0 was used to evaluate RP. We evaluated the relationship between clinical backgrounds, the degree of emphysema (%LAV, MD), radiation dose (the percentage of pulmonary volume irradiated to >20Gy (V20), mean lung dose (MLD)) and RP. Results: 33 patients were analyzed, of which 19 (58%) had symptomatic RP (>= Grade2) and 14 (42%) had asymptomatic RP (=Grade1). Age, sex, pathology and stage in patients were similar between both groups. There is no significant difference in forced expiratory volume in 1 second (FEV1) between the symptomatic group and the asymptomatic group (2.23 + -0.60L vs 2.35 + -0.50L, P = 0.296). The symtomatic group had significantly more severe PE (LAV% 10.9 + -8.7% MD -880 ± 21HU) than the asymptomatic group (LAV% 4.4 + -4.0% (P = 0.025), MD -856 + -24 HU (P = 0.002)), respectively. Radiation dose was significantly higher in the symptomatic group (V20 24.6 + -5.1%, MLD 12.9 + -3.4Gy) than the asymptomatic group ((V20 19.9 + -3.3% (P = 0.005), MLD 9.1 + -3.2Gy (P = 0.002)). Conclusions: Severity of emphysma appears to be a factor that can be used to predict RP after concurrent chemoradiotherapy for lung cancer. Disclosure: All authors have declared no conflicts of interest.

Risk Factors for Radiation Pneumonitis in Patients With Lymphoma Treated With Chemotherapy and Photon or Proton Radiation Therapy

Risk Factors for Radiation Pneumonitis in Patients With Lymphoma Treated With Chemotherapy and Photon or Proton Radiation Therapy

Preliminary analysis of the risk factors for radiation pneumonitis in patients with non-small-cell lung cancer treated with concurrent erlotinib and thoracic radiotherapy.

PurposeThe aim of this study was to investigate radiation pneumonitis and its associated risk factors in patients with non-small-cell lung cancer treated with concurrent erlotinib and thoracic radiotherapy.Materials and methodsWe conducted an analysis of patients with nonoperable stage IIIA–IV non-small-cell lung cancer who were treated with concurrent thoracic radiotherapy and erlotinib (ClinicalTrials.gov identifier: NCT00973310). The Common Terminology Criteria for Adverse Events version 3.0 grading system was applied to evaluate the incidence of radiation pneumonitis. The lung dosimetric parameters were recorded in accordance with the treatment plan, and the study endpoint was radiation pneumonitis at grade 2 or more.ResultsAmong the 24 selected clinical cases, nine were identified with radiation pneumonitis of grade 2 or above (37.5%). This included four cases with grade 2 (16.7%), two cases with grade 3 (8.3%), and three cases with grade 5 (12.5%). The results showed that the planning target volume was a significant factor affecting the incidence of radiation pneumonitis. All lung dosimetric parameters exhibited statistically significant differences between patients with pneumonitis and patients without pneumonitis. The receiver operating characteristic (ROC) curve analysis showed that all lung dosimetric parameters were useful in predicting the incidence of radiation pneumonitis. In addition, the threshold values of V5, V10, V15, V20, V30, and mean lung dose were >44%, >29%, >27%, >22%, >17% and >1,027 cGy, respectively.ConclusionSpecial attention should be paid to the adverse effects of radiation pneumonitis in concurrent thoracic radiotherapy and erlotinib treatment. Lung dosimetric parameters are important predictive factors in radiation pneumonitis.

Risk Factors For Radiation Pneumonitis In Patients With Lymphoma Treated With Chemotherapy and Photon Or Proton Radiotherapy

IntroductionAs volume-based radiotherapy planning has become a more standard part of combined modality therapy for lymphomas, dose-volume based constraints for organs-at-risk are needed for treatment planning. Conformal techniques such as intensity modulated radiation therapy and proton radiotherapy may achieve lower doses to certain organs like the heart, but may result in higher doses to other tissues like the lungs and breasts. We sought to define the dosimetric risk factors that are associated with development of radiation pneumonitis (RP). MethodsThis is a single-institution retrospective analysis of patients with thoracic lymphomas treated with combined modality therapy between 1999 and 2013 who had at least 4 months of follow-up after radiotherapy. Univariate analyses (UVA) were performed using Fisher exact and Wilcoxon rank-sum tests. ResultsOf the 89 patients analyzed, 13 (14.6%) were diagnosed with RP (at least Grade 1, Common Toxicity Criteria v4.0). Patients were predominantly female (62%) and never smoked (67%). Diagnoses were grouped as Hodgkin lymphoma (62.9%) or non-Hodgkin lymphoma (37.1%), and 18.5% were also treated with autologous stem cell transplants. UVA showed that RP was more commonly associated with a diagnosis of non-Hodgkin lymphoma (38%) than Hodgkin lymphoma (8%), despite exposure to bleomycin in the majority of patients with Hodgkin lymphoma. Higher lung doses were significantly associated with RP using multiple lung dose-volume parameters: mean lung dose (12.3 vs. 16.7 Gy, p=0.002), volume of lung receiving 20 Gy (27.3% vs. 39.1%, p=0.0009), and volume of lung receiving 5 Gy (51% vs. 66.8%, p=0.004). The majority (67%) of patients who developed RP had mean lung doses of over 15 Gy, whereas only 24% of those who did not develop RP had mean lung doses above 15 Gy, see Figure. Heart dosimetric parameters were also significantly associated with RP, including mean heart dose (13.3 vs. 21.5 Gy, p=0.004), volume of heart receiving 20 Gy (25.4% vs. 48.3%, p=0.003), and volume of heart receiving 5 Gy (57.6% vs. 81.1%, p=0.04). There were not enough events to determine if heart and lung parameters were independently associated with RP, but they were strongly correlated (R=0.75). [Display omitted] Gender, smoking history, and autologous transplant were not significantly associated with RP. None of the 13 patients treated with proton radiotherapy developed RP. In general, patients treated with proton radiotherapy had lower mean heart doses (9.4 vs. 15.4 Gy) and mean lung doses (9.6 Gy vs. 13.5 Gy). ConclusionsHigher doses to lung and heart are associated with increased risk of RP, and doses to these critical structures should be considered carefully during volume-based consolidative radiotherapy using advanced techniques. Disclosures:No relevant conflicts of interest to declare.

Impact of diabetes mellitus on clinicopathological factors and relation with radiation pneumonitis in 332 patients with lung cancer

To explore the relation between diabetes mellitus and clinicopathological factors and the incidence of radiation pneumonitis in patients with non-small cell lung cancer. The data of 332 patients with non-small cell lung cancer, who were admitted to the Department of Oncology of Third Xiangya Hospital of Central South University between January 2007 and August 2009, were collected retrospectively. The patients were divided into a diabetes mellitus (DM) group (n=45) and a non-diabetes mellitus (NDM) group (n=287). The clinicopathological factors were compared between the two groups. The patients who received radiotherapy were further divided into a diabetes mellitus (DMR) group (n=33) and a non-diabetes mellitus group (NDMR) group(n=287), and the incidence of radiation pneumonitis was compared. A total of 45 patients (13.55%)developed diabetes mellitus. There was significant difference in the body-weight, age and hypertension (P<0.05), while no significant difference in the pathologic factors, such as tumor pathological type, degree of differentiation, and classification of malignant tumors (TNM) stage between the two groups(P>0.05). No significant difference in the irradiation area was found between the DM group and the NDM group(P>0.05). The incidence of radiation pneumonitis in the DMR group was 42.42%(14 out of 33), while 21.31%(39 out of 183) in the NDMR group, with significant difference in the incidence of radiation pneumonitis between the DMR group and the NDMR group(P<0.05). The risk value in the DMR group was 2.721 folds (95%CI, 1.253-5.910) that in the NDMR group in patients with non-small cell lung cancer companied with diabetes mellitus. Diabetes mellitus is the risk factor of radiation pneumonitis for patients with nonsmall cell lung cancer who receive radiotherapy.

Predicting Radiation Pneumonitis After Stereotactic Ablative Radiation Therapy in Patients Previously Treated With Conventional Thoracic Radiation Therapy

To determine the incidence of and risk factors for radiation pneumonitis (RP) after stereotactic ablative radiation therapy (SABR) to the lung in patients who had previously undergone conventional thoracic radiation therapy. Seventy-two patients who had previously received conventionally fractionated radiation therapy to the thorax were treated with SABR (50 Gy in 4 fractions) for recurrent disease or secondary parenchymal lung cancer (T<4 cm, N0, M0, or Mx). Severe (grade≥3) RP and potential predictive factors were analyzed by univariate and multivariate logistic regression analyses. A scoring system was established to predict the risk of RP. At a median follow-up time of 16 months after SABR (range, 4-56 months), 15 patients had severe RP (14 [18.9%] grade 3 and 1 [1.4%] grade 5) and 1 patient (1.4%) had a local recurrence. In univariate analyses, Eastern Cooperative Oncology Group performance status (ECOG PS) before SABR, forced expiratory volume in 1 second (FEV1), and previous planning target volume (PTV) location were associated with the incidence of severe RP. The V10 and mean lung dose (MLD) of the previous plan and the V10-V40 and MLD of the composite plan were also related to RP. Multivariate analysis revealed that ECOG PS scores of 2-3 before SABR (P=.009), FEV1≤65% before SABR (P=.012), V20≥30% of the composite plan (P=.021), and an initial PTV in the bilateral mediastinum (P=.025) were all associated with RP. We found that severe RP was relatively common, occurring in 20.8% of patients, and could be predicted by an ECOG PS score of 2-3, an FEV1≤65%, a previous PTV spanning the bilateral mediastinum, and V20≥30% on composite (previous RT+SABR) plans. Prospective studies are needed to validate these predictors and the scoring system on which they are based.

A Dose–Volume Analysis of Radiation Pneumonitis in Non–Small Cell Lung Cancer Patients Treated With Stereotactic Body Radiation Therapy

To examine the rates and risk factors of radiation pneumonitis (RP) in non-small cell lung cancer (NSCLC) patients treated with stereotactic body radiotherapy (SBRT). Dosimetry records for 251 patients with lymph node-negative Stage I-IIB NSCLC and no prior chest radiation therapy (RT) treated with SBRT were reviewed. Patients were coded on the basis of the presence of at least Grade (G) 2 RP using the Common Toxicity Criteria version 2 criteria. Radiation doses, V5, V10, V20, and mean lung dose (MLD) data points were extracted from the dose-volume histogram (DVH). Median PTV volume was 48 cc. Median prescribed radiation dose was 60 Gy delivered in three fractions to the 80% isodose line. Median age at treatment was 74 years. Median follow-up was 17 months. RP was reported after treatment of 42 lesions: G1 in 19 (8%), G2 in 17 (7%), G3 in 5 (2%), and G4 in 1 (0.4%). Total lung DVHs were available for 143 patients. For evaluable patients, median MLD, V5, V10, and V20 were 4.1 Gy, 20%, 12%, and 4%, respectively. Median MLDs were 4 Gy and 5 Gy for G0-1 and G2-4 groups, respectively (p = 0.14); median V5 was 20% for G0-1 and 24% for G2-4 (p = 0.70); median V10 was 12% in G0-1 and 16% in G2-4 (p = 0.08), and median V20 was 4% in G0-1 and 6.6% in G2-4 (p = 0.05). G2-4 RP was noted in 4.3% of patients with MLD ≤4 Gy compared with 17.6% of patients with MLD >4 Gy (p = 0.02), and in 4.3% of patients with V20 ≤4% compared with 16.4% of patients with V20 >4% (p = 0.03). Overall rate of G2-4 RP in our population treated with SBRT was 9.4%. Development of symptomatic RP in this series correlated with MLD and V20.

Heart irradiation as a risk factor for radiation pneumonitis

Purpose. To investigate the potential role of incidental heart irradiation on the risk of radiation pneumonitis (RP) for patients receiving definitive radiation therapy for non-small-cell lung cancer (NSCLC). Material and methods. Two hundred and nine patient datasets were available for this study. Heart and lung dose-volume parameters were extracted for modeling, based on Monte Carlo-based heterogeneity corrected dose distributions. Clinical variables tested included age, gender, chemotherapy, pre-treatment weight-loss, performance status, and smoking history. The risk of RP was modeled using logistic regression. Results. The most significant univariate variables were heart related, such as heart heart V65 (percent volume receiving at least 65 Gy) (Spearman Rs = 0.245, p < 0.001). The best-performing logistic regression model included heart D10 (minimum dose to the hottest 10% of the heart), lung D35, and maximum lung dose (Spearman Rs = 0.268, p < 0.0001). When classified by predicted risk, the RP incidence ratio between the most and least risky 1/3 of treatments was 4.8. The improvement in risk modeling using lung and heart variables was better than using lung variables alone. Conclusions. These results suggest a previously unsuspected role of heart irradiation in many cases of RP.

Dose–Volume Analysis of Radiation Pneumonitis in Non–Small-Cell Lung Cancer Patients Treated With Concurrent Cisplatinum and Etoposide With or Without Consolidation Docetaxel

To examine the rates and risk factors for radiation pneumonitis (RP) in non-small-cell lung cancer (NSCLC) patients treated with chemoradiotherapy. We reviewed dosimetry records from Stage III NSCLC patients treated on a prospective randomized trial. Patients received concurrent cisplatinum/etoposide with radiation therapy to 59.4 Gy. A total of 243 patients were enrolled; 167 did not experience progression and were randomized to observation (OB) or consolidation docetaxel (CD). Toxicity was coded based on the presence of Grade 0 to 1 vs. Grade 2 to 5 RP using the Common Toxicity Criteria and Adverse Events (CTCAE) v3.0. Median age and follow-up were 63 years and 16 months, respectively. Overall, Grade 0 to 1 and Grade 2 to 5 RP were reported in 226 patients and 17 patients (7%) respectively. Median mean lung dose (MLD), V5, V20, and V30 for evaluable patients were 18 Gy, 52%, 35%, and 29%. MLD in Grade 0 to 1 and Grade 2 to 5 patients was 1,748 c Gy and 2,013 cGy in respectively (p = 0.12). Grade 2 to 5 RP developed in 2.2% and 19% of patients with MLD < 18 Gy and MLD > 18 Gy, respectively (p = 0.015). Mean V20 was 33.7% and 37.7% for Grade 0 to 1 and Grade 2 to 5 groups, respectively (p = 0.29). Grade 2 to 5 RP developed in 4.8% and 17% of patients with V20 < 35% and V20 > 35%, respectively. The OB and CD groups had similar MLD and V20, and the RP rates were 3.6% and 14.6%, respectively (p = 0.015). Patients who developed Grade 0 to 1 and Grade 2 to 5 RP had similar mean V5, V10, V15, V20, V25, V30, age, smoking history, and tumor characteristics. The overall rate of Grade 2 to 5 RP was 7% in patients treated with chemoradiotherapy. In this analysis, predictive factors for RP were MLD > 18 Gy and treatment with CD.

TH‐C‐BRD‐04: Impact of Various Lung Volumes On Radiotherapy Planning of Lung Cancer

Purpose: Dose volume histogram (DVH) parameters of the lung have been reported to be risk factors for radiation pneumonitis. We evaluated different lung volumes using 4DCTs to determine the optimal data sets for lung contouring and to develop a model to convert the DVH parameters between datasets. Methods and Materials: A retrospective analysis was performed on 10 patients' 4DCT and fast helical free breathing scans. The lungs were automatically contoured on the averaged (AVG_CT), end expiration (EE), end inspiration (EI), free breathing (FB), maximum intensity projection (MIP) and mean position (MP) images. Volumes and centers of mass were compared to those obtained with deformable image registration (AVG_def). AVG_def contours were created by averaging displacement vectors for each image pixel over the 4DCT, representing the averaged contour due to organ motion. To compare DVH parameters (V20, V12.5 and MLD), patients' plans were standardized as hypo‐fractionated. A population‐based model was tested for converting DVH parameters between datasets. Results: A paired Student's t‐test showed significant variation between AVG_def and other volumes. MP image volume was most statistically similar (0.479%). Centers of mass between image volumes showed little relevant variation. Marked volume effect was observed for dose‐volume relationships. MP image DVH parameters were most statistically similar to those of the AVG_def (&lt; 1%). An average percentage change of 3.95% was observed between V20 of EI and AVG_def volumes. A model to convert from one DVH parameter to another was effective when comparing different volumes. Conclusion: There was a marked variation between the volumes and DVH parameters obtained from EI, MIP and EE images and those of AVG_def. The most statistically similar image, in terms of volume and DVH analysis, was the MP. A model can be used, with caution, in converting the DVH parameters from one image to another.

Risk factors for radiation pneumonitis caused by whole breast irradiation following breast-conserving surgery

We evaluated risk factors of radiation pneumonitis (RP) after whole breast irradiation following breast-conserving surgery. Four hundred and seventy-two cases underwent whole breast irradiation with tangential field following breast-conserving surgery in our hospital, between January 2005 and April 2007. Of these cases, we performed statistical analyses for 423 breasts of 413 patients, using a pulmonary dose-volume histogram. Patient characteristics, treatment regimens and irradiation methods were included as variables in the analyses on risk factors of RP. As a result, 89 breasts of 84 cases (21%) were diagnosed with RP. The version 3.0 of the NCI Common Terminology Criteria for Adverse Events was used to evaluate the grade of pneumonitis: 77 cases (18.2%) were diagnosed as Grade 1 RP, 10 cases (2.3%) as Grade 2, and 2 cases (0.5%) as Grade 3. Multivariate analysis indicated that the significant risk factors for RP were central lung distance (CLD) (>1.8 cm) and the short axis length of the radiation field. The incidence of radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome significantly correlated only with CLD. The lung volume within the radiation field was shown to be a significant risk factor for RP and radiation-induced BOOP syndrome.

High-dose Bronchial Irradiation is a Statistically Significant Risk Factor for Radiation Pneumonitis within Logistic-multivariate Modeling

High-dose Bronchial Irradiation is a Statistically Significant Risk Factor for Radiation Pneumonitis within Logistic-multivariate Modeling

High-dose Heart Irradiation is a Statistically Significant Risk Factor for Radiation Pneumonitis within Logistic-multivariate Modeling

To detect and quantify, within a multivariate framework, the effect of heart irradiation on the risk of radiation pneumonitis (RP) for radiotherapy patients treated for lung cancer. All evaluable, archived 3D treatment plans for patients with registered outcomes treated for NSCLC between 1991 and 2001 were eligible. RP which resulted in steroid use or more intensive intervention was classified as an event (WUSTL Grade 2 or higher; RTOG Grade 3 or higher). Doses were retrospectively corrected for heterogeneity effects via a Monte Carlo-based method. Plans were processed and reviewed using CERR (computational environment for radiotherapy research). Heart volumes were re-contoured within CERR by a single physician (n = 209, with 48 RP events). Heart and normal lung (lung minus gross tumor volume) dose-volume parameters were extracted for further modeling using CERR. Evaluated factors included clinical (age, gender, race, performance status, weight loss, smoking, histology); dosimetric parameters for heart (D5-D100, V10-V80, mean dose, maximum dose, and minimum dose); treatment factors (chemotherapy, treatment time, fraction size); location parameters (heart center-of-dose, sup-inf within the heart); as well as previously identified significant lung parameters: mean lung dose and sup-inf tumor position (GTV center-of-mass) within the lung (Bradley JD et al., IJROBP 2007;69(4):985-992). A best multivariate model was obtained by step-wise variable selection and logistic regression. The best model order was determined using leave-one-out cross validation. Statistically significant variables with the highest univariate Spearman rank correlations included: maximum heart dose (0.227, p < 0.0006), heart V70 (0.239, p < 0.0003), heart D5 (minimum dose to the hottest 5% of the heart) (0.256, p < 0.0002), heart D10 (0.24, p < 0.0003), heart gEUD (0.249 for a = 10, p < 0.0001), and GTV_COMSI (0.219, p < 0.0008). Leave-one-out cross-validation analysis supported a model order of four variables (with rank correlation coefficients on the out-of-sample points of about 0.3). The most commonly selected variables were (in order of decreasing frequency): heart D10, heart D30, mean lung dose, and GTV_COMSI within the lung. Heart dose-volume parameters were more statistically significant than any previously derived lung parameters within a multivariate modeling framework to predict RP. These correlations should be tested further against new datasets.

Risk factors of radiation pneumonitis in lung cancer

7573 Background: The clinical syndrome of radiation pneumonitis develops in 5–15% of patients receiving thoracic radiotherapy for lung cancer. In this study, we evaluated and identified the clinical characteristics, clinical courses of patients who developed radiation pneumonitis compared with patients who did not develop radiation pneumonitis. Methods: One hundred and five lung cancer patients who underwent thoracic radiotherapy between January 2001 and January 2006 were evaluated and clinical characteristics were reviewed retrospectively. Results: The median age of total patients was 60.9 years old and 86 cases (81.9%) of non-small cell lung cancer and 19 cases (18.1%) of small cell lung cancer patients were enrolled. Forty-one cases(39.0%) developed radiation pneumonitis. Among these patients, 23 cases (56.1%) of early radiation pneumonitis, 15 (36.7%) of intermediate and 3 (7.2%) of late were classified by development time. By severity, 10 cases (24.4%) of Grade 1, 23 (56.1%) of Grade 2, 7 (17.1%) of Grade 3 and 1 of Grade 4 radiation pneumonitis were observed. 21cases (51.2%) of patients who developed radiation pneumonitis were treated with corticosteroid for mean duration of 9.8 weeks. Non-smoking history (p=0.046), concomitant other lung disease (p=0.021), and NTCP (Normal Tissue Complication Probability)≥30% (p=0.012) significantly increased risk of radiation pneumonitis development in multivariate analysis. Development of radiation pneumonitis did not affect survival (p=0.456). Conclusions: Radiation pneumonitis was developed in 39% of patients who had received thoracic radiation due to primary lung cancer and 56.1% cases of these radiation pneumonitis patients developed within 2 months. In this study, non-smoking history, concomitant other lung disease and NTCP≥30% were identified as risk factors of radiation pneumonitis, thus, more attention will be needed to these patients group. No significant financial relationships to disclose.

6600 POSTER Risk factors of radiation pneumonitis: a prospective study

To evaluate the efficacy and safety of irinotecan and bevacizumab in recurrent ovarian cancer. The primary objective was to estimate the progression free survival (PFS) rate at 6 months. Secondary objectives included estimation of overall survival (OS), objective response rate (ORR), duration of response, and an evaluation of toxicity.Recurrent ovarian cancer patients with no limit on prior treatments were eligible. Irinotecan 250 mg/m2 (amended to 175 mg/m2 after toxicity assessment in first 6 patients) and bevacizumab 15 mg/kg were administered every 3 weeks until progression or toxicity. Response was assessed by RECIST or CA-125 criteria every 2 cycles.Twenty nine patients enrolled (10 were platinum-sensitive and 19 were platinum-resistant). The median number of prior regimens was 5 (range 1–12); 13 patients had prior bevacizumab and 11 prior topotecan. The PFS rate at 6 months was 55.2% (95% CI: 40%–77%). The median number of study cycles given was 7 (range 1–34). Median PFS was 6.8 months (95% CI: 5.1–12.1 months); median OS was 15.4 months (95% CI: 11.9–20.4 months). In this study, no complete response (CR) was observed. The objective response rate (ORR; PR or CR) for all patients entered was 27.6% (95% CI: 12.7%–47.2%) and the clinical benefit rate (CR + PR + SD) was 72.4% (95% CI: 52.8%–87.3%); twelve patients experienced duration of response longer than 6 months. In the 24 patients with measurable disease, a partial response (PR) was documented in 8 (30%) patients; 13 patients maintained stable disease (SD) at first assessment. The most common grade 3/4 toxicity was diarrhea. No treatment-related deaths were observed.Irinotecan and bevacizumab has activity in heavily pre-treated patients with recurrent ovarian cancer, including those with prior bevacizumab and topoisomerase inhibitor use.

Risk factor of radiation pneumonitis: assessment with velocity-encoded cine magnetic resonance imaging of pulmonary artery.

The aim of this study was to investigate whether the pulmonary arterial flow obtained as a function of time from velocity-encoded cine (VEC) magnetic resonance (MR) imaging can be used to predict radiation pneumonitis. Before receiving radical radiotherapy, 19 patients with primary lung cancer and 21 with primary esophageal cancer underwent VEC MR imaging to determine their pulmonary arterial flow. The right and left pulmonary arterial flow profiles were digitized, and from these data, acceleration time, maximal change in flow rate during ejection, acceleration volume, and the ratio of maximal change in flow rate during ejection to acceleration volume were measured. The statistical significance of differences in pulmonary arterial flows before irradiation between patients who developed and did not develop RP greater than grade 1 was determined. Radiation pneumonitis occurred in 5 patients with lung cancer and in 4 with esophageal cancer. The acceleration time (P < 0.001), acceleration volume (P < 0.02), and ratio of the maximal change in flow rate during ejection to acceleration volume (P < 0.002) in patients with and without RP were significantly different. The sensitivity, specificity, and accuracy of using 111 milliseconds as the cutoff value (which was the mean acceleration time in the RP group) to predict RP were 58%, 88%, and 83%, respectively. Pulmonary hypertension detected by VEC MR imaging can be a risk factor for development of RP in candidates for pulmonary irradiation.

171 oral Clinical and dosimetric risk factors of radiation pneumonitis in 3D conformal irradiation of thoracic cancer

171 oral Clinical and dosimetric risk factors of radiation pneumonitis in 3D conformal irradiation of thoracic cancer

894 Poster Clinical and dosimetric risk factors of radiation pneumonitis in lung cancer patients: a retrospective study

894 Poster Clinical and dosimetric risk factors of radiation pneumonitis in lung cancer patients: a retrospective study

2161 The impact of radiation dose and fractionation on the risk factor of radiation pneumonitis on four radiation therapy oncology group (RTOG) lung cancer trials

2161 The impact of radiation dose and fractionation on the risk factor of radiation pneumonitis on four radiation therapy oncology group (RTOG) lung cancer trials