EP-1204: Treatment Outcomes and Patterns of Radiologic Injury after Tomotherapy-based SBRT for Lung Tumours

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Patients with NSCLC were treated with a total dose of 74 Gy, those with SCLC with 60 Gy and those with esophageal tumors with 66 Gy. Fraction dose/day was 2 Gy each. Patients were treated with or without concurrent or sequential chemotherapy according to intradepartmental standards. Data regarding clinical outcome (survival, side effects, local and distant control), PFT (ventilation and diffusion parameters) and quality of life (EORTC QLQ-C30 and QLQ-LC13) were collected before RT, 6 weeks, 12 weeks and 6 months after treatment. QoL data was additionally collected 1 year post RT. Radiological followup via CT focusing on lung density changes was done 12 weeks and 6 months after RT. Results The median follow up was 34,5 weeks. There was no significant difference regarding the local (p = 0,954) and distant (p = 0,206) outcome, side effects (all p > 0,05) or survival (p = 0,633) of patients in the two treatment arms at any follow up appointment. The comparison of the PFT showed a statistically significant difference for the DLCO 6 weeks post RT (p = 0,028). All other parameters did not differ significantly at any follow up appointment. Regarding the QoL there was no statistically significant difference between the summarized value for the QLQC30 and the QLQ-LC13 at any follow up appointment (p > 0,1). There was a statistically significant difference between the mean density of the lung parenchyma at 12 weeks (p < 0,0005) and 6 months post RT (p < 0,0005). Conclusion Since there was no significant and relevant difference between both treatment arms regarding PFT, clinical outcome and QoL it doesn’t seem to relevant how the DVH is shaped exactly as long as certain established dose constrains are respected. As to whether the difference between the CT density changes is not only significant but also clinically relevant further analysis is needed.

capacity for carbon monoxide (DLCO) and capillary blood gas analysis. Additionally the influence of patient and treatment related factors on PFT was analyzed. Results The mean FEV1 constantly declined during the follow up (p = 0,001). In total 68 % of patients had a reduced FEV1 at 6 months. The general linear model (GLM) with repeated measures determined that the FEV1 differed statistically significant over time (p = 0,001). The mean VC didn’t change during the follow up (p > 0,05). The mean TLC showed a constant decline after RT (p = 0,026). At 6 months 60 % of patients showed a decline in VC and 73 % in TLC. The GLM revealed no significant changes of the VC over time. There was a difference between the TLC before RT and at 6 months post RT (p = 0,026). The mean DLCO had declined at 6 and 12 weeks but showed a slight recovery at 6 months (p < 0,0005). At 6 months 86 % of patients had a reduced DLCO. The GLM determined that there where statistically significant differences of the DLCO over time (p < 0,0005). There was an increase in pCO2 and a decrease in pO2 after treatment (p > 0,05). At 6 months approximately 60 % had a decline in pO2 and an increase in pCO2. Only the pre-treatment PFT classification had a significant influence on the FEV1 after RT. The GLM determined no statistically significant changes of the blood gas parameters over time. Only the pre-treatment PFT classification had a significant influence on the FEV1 after RT. Conclusion The DLCO seems to be the most reliable indicator for lung tissue damage after thoracic radiotherapy. Although there might be some significance ventilation parameters appear to be less reliable. Only the pre-treatment PFT classification had a significant influence on the FEV1 after RT.

EP-1203 Changes in pulmonary function after high dose intrathoracic radio(-chemo)therapy up to 74 Gy C. Schröder1, R. Engenhart-Cabillic2, A. Buchali3 1 Universität Giessen, Klinik für Strahlentherapie und Radioonkologie- Universitätsklinikum Giessen und Marburg, Giessen, Germany 2 Universität Marburg, Klinik für Strahlentherapie und Radioonkologie- Universitätsklinikum Giessen und Marburg, Marburg, Germany 3 Ruppiner Kliniken GmbH, Klinik für Strahlentherapie und Radioonkologie, Neuruppin, Germany

EP-1204 Treatment Outcomes and Patterns of Radiologic Injury after Tomotherapy-based SBRT for Lung Tumours S. Arcangeli1, L. Falcinelli2, S. Bracci3, A. Greco3, A. Monaco1, J. Dognini1, C. Chiostrini1, R. Bellavita2, C. Aristei2, V. Donato1 1 San Camillo-Forlanini Hospitals, Radiation Oncology, Rome, Italy 2 S. Maria della Misericordia University Hospital, Radiation Oncology, Perugia, Italy 3 S.Andrea University Hospital, Radiation Oncology, Rome, Italy

Purpose or Objective There are numerous ways to examine radiation therapy (RT) related injuries to the lung tissue. Next to obvious factors like treatment induced side effects, the changes in pulmonary function are a simple way to quantify the effects of RT on a patient’s lung. In this study we prospectively collected patient-related, dose-related and PFT data before RT and at several follow up visits after RT to analyze the time course of PFT changes and influencing factors. Material and Methods From 04/12 to 10/15 81 patients with NSCLC, SCLC or esophageal carcinoma where treated with high dose radiation therapy. Patients with NSCLC where treated with a total dose of 74 Gy, those with SCLC with 60 Gy and those with esophageal tumors with 66 Gy. Fraction dose was 2 Gy each. Patients were treated with or without concurrent or sequential chemotherapy according ti intradepartmental standards. Data regarding PFT (ventilation and diffusion parameters) was collected before treatment, 6 weeks, 12 weeks and 6 months after RT. The following lung function parameters were analyzed: vital capacity (VC), total lung capacity (TLC), forced expiratory volume in 1 second (FEV1), diffusion

Purpose or Objective To evaluate treatment outcomes and patterns of CT lung injury after hypofractionated image-guided stereotactic body radiotherapy (SBRT) delivered with helical tomotherapy (HT) in a series of inoperable lung lesions. Material and Methods 68 medically inoperable patients (69 lesions) without evidence of viable extrathoracic disease were included. Assessment of tumor response was based on the RECIST 1.1 criteria coupled with a 18F-FDG/PET-CT. Toxicity monitoring was focused on treatment-related pulmonary adverse events according to the CTCAE v. 4.0. Acute and late events were classified as radiation pneumonitis (RP) and radiation fibrosis (RF), respectively. Kaplan-Meier survival analysis was used to evaluate the progression-free (PFS) and overall survival (OS). Results After a median follow-up of 12 months (range, 3–31 months), no istances of ≥ Grade 4 RP was documented and clinically severe (Grade 3) RP occurred in 5.8% of the patients. Two patients (3%) developed a late severe (≥Grade 3) symptomatic RF. No specific pattern of CT lung injury was demonstrated, in both acute and late setting. Median OS and PFS for the entire population were 30.8 and

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14.1 months, respectively. At MVA, BED ≥100 and KPS ≥90 emerged as a significant prognostic factors for OS (p = 0.01 and p = 0.001, respectively), and BED ≥100 for PFS (p = 0.02). Conclusion Our findings show that a risk adaptive approach of HTSBRT based on tumor location is an effective treatment with a mild toxicity profile in medically inoperable patients with lung tumors. No specific pattern of lung injury was demonstrated. EP-1205 The prognostic role of Neutrophil-tolymphocyte ratio in limited disease small-cell lung cancer L. Käsmann1, L. Bolm1, L. Motisi1, S. Janssen1, S.E. Schild2, D. Rades1 1 University of Lübeck, Department of Radiation Oncology, Lubeck, Germany 2 Mayo Clinic, Department of Radiation Oncology, Scottsdale- AZ, USA Purpose or Objective Small cell lung cancer is an aggressive cancer type of neuroendocrine origin. Even patients with limited disease have a poor prognosis of 16-24 months. Standard treatment of these patients is radiochemotherapy with cisplatin and etoposide followed by prophylactic cranial irradiation. Systemic inflammation has been suggested an important prognostic factor for outcome in several types of cancer. In this study, we investigated the impact of systematic inflammation represented by the neutrophilto-lymphocyte ratio (NLR) at diagnosis in patients with limited disease small-cell lung cancer (LD-SCLC) for outcomes. Material and Methods Data of 65 patients receiving radiochemotherapy for LDSCLC were analyzed. NLR was obtained from blood samples at diagnosis. NLR plus 12 factors, namely gender, age, ECOG performance score, T-category, N-category, number of pack years, smoking during radiotherapy (RT), respiratory insufficiency prior to RT, haemoglobin levels during RT, EQD2 (<56 Gy vs. ≥56 Gy), concurrent chemotherapy and PCI, were evaluated for local control, metastases-free survival and overall survival. Results The overall survival rates at 12, 24 and 36 months were 71%, 45% and 28%, respectively. Median survival time was 20 months. On univariate analysis of local recurrence, lower T-stage (1-2 vs. 3-4) was associated with improved local control at 36 months (62% vs. 41%, p=0.04). On multivariate analysis, T-stage was an independent factor (p=0.035; HR 1.84 (95% Cl 1.04-3.86)). Improved metastases-free-survival on univariate analyses was found for NLR <4 (p=0.011), ECOG 0-1 (p=0.002), nodal stage N01 (p=0.048), non-smoking during RT (p=0.009), and administration of PCI (p=0.006). On multivariate analysis, a trend for improved metastases-free-survival was observed for NLR <4 (p=0.063; HR 2.19 (95% Cl 0.96-5.06)) and N0-1 (p=0.0623; HR 3.4 (95% Cl 0.95-21.9)). Improved overall survival rates were found for NLR <4 (p=0.001), ECOG 0-1 (p<0.001), non-smoking during RT (p=0.007), no respiratory insufficiency prior to RT (p=0.03) and PCI (p<0.001). On multivariate analysis, NLR <4 (p=0.03; HR 2.05 (95% Cl 1.06-3.95)), ECOG 0-1 (p=0.002; HR 3.41 (95% Cl 1.57-7.36)) and PCI (p=0.015; HR 2.56 (95% Cl 1.21-5.34) were independently associated with improved survival. Conclusion In this study, NLR was an independent prognostic factor for overall survival in patients with LD-SCLC. NLR can help identify patients with poor prognosis and appears an useful prognostic marker in clinical practice. A prospective analysis is warranted to confirm our findings.

EP-1206 FDG-PET/CT predictive parameters of early response after SABR for lung oligometastases R. Mazzola1, N. Giaj Levra1, A. Fiorentino1, S. Fersino1, F. Ricchetti1, U. Tebano1, D. Aiello1, R. Ruggieri1, F. Alongi1 1 Sacro Cuore Don Calabria Cancer Care Center, Radiation Oncology, Negrar-Verona, Italy Purpose or Objective To investigate the role of 18FDG-PET/CT parameters as predictive of early response after Stereotactic Ablative Radiation Therapy (SABR) for oligometastases lung lesions. Material and Methods SABR for lung oligometastases was performed when the following criteria were satisfied: a) controlled primary tumor, b) absence of progressive disease longer than 6 months, c) number of metastatic lesions ≤ 5. The prescribed total dose varied according to the risk-adapted dose prescription with a range of doses between 48-70 Gy in 3-10 fractions. Inclusion criteria of the current retrospective study were: a) lung oligometastases underwent to SABR, b) for each patient presence of 18FDG-PET/CT pre- and post-SABR for at least two subsequent evaluations, c) Karnofsky performance status > 80, d) life-expectancy > 6 months. The following metabolic parameters were defined semiquantitatively for each lung lesion: 1) SUV-max, 2) SUVmean, 3) Metabolic Tumor Volume (MTV), 4) Total Lesional Glycolysis (TLG). Results From January 2012 to November 2015 fifty patients for a total of seventy lung metastatic lesions met the inclusion criteria of the present analysis. Pre-SABR, median SUVmax was 6.5 (range, 4 - 17), median SUV-mean was 3.7 (2.5 - 6.5), median MTV was 2.3 cc (0.2 - 31 cc). For patients with in-field disease progression median TLG was 17.4 (2 - 52.8), for the remaining the median value was 170.6 (0.5 - 171). For pre-SABR SUV-max ≥ 5 a progression/stable metastasis was noted in 88% of cases, while a complete response was observed in 94% of cases for pre-SABR SUV-max < 5 (p < 0.001, Sensitivity = 88%, Specificity = 94%). A pre-SABR SUV-mean < 3.5 was related to complete response at 6 months after SABR (p 0.03, Sensitivity = 31%, Specificity = 34%, AUC = 0.32). In cases of in-field failure, a pre-SABR SUV-max > 8 was related to a higher absolute value increase of SUV-max at 6 months of follow up comparing to pre-SABR SUV-max < 8 (p 0.005). Delta SUV max 3-6 months was +126% for lesions with infield progression versus -26% for the remaining (p-value 0.002). Delta SUV-mean 3-6 months was +15% for lesions with in-field progression versus for the remaining metastases (p-value 0.008). Finally, 86% of patients with local failure had distant progression versus only 19% in cases without local failure (p = 0.004). Conclusion According to current findings, pre-SABR SUV max and mean seem to predict early response in lung SABR for oligometastases. EP-1207 Outcomes and prognostic factors in solitary brain metastasis from small cell lung cancer D. Bernhardt1, S. Adeberg1, F. Bozorgmehr2, J. Kappes3, J. Hoerner-Rieber1, L. Koenig1, J. Debus1, M. Thomas2, A. Unterberg4, F. Herth3, C.P. Heussel5, M. Steins2, S. Rieken1 1 University Hospital of Heidelberg, Department of Radiation Oncology, Heidelberg, Germany 2 University Hospital of Heidelberg, Department of Thoracic Oncology- Thoraxklinik- Translational Lung Research Centre Heidelberg TLRC-H, Heidelberg, Germany 3 University Hospital of Heidelberg, Department of Pneumology- Thoraxklinik, Heidelberg, Germany 4 University Hospital of Heidelberg, Department of