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EP-1173: Study of offline setup error adaptive correction during radiotherapy for NSCLC based on online CBCT data
ESTRO 33, 2014
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intensity modulated radiotherapy (IMRT) on both normal tissues and target volumes. Materials and Methods: Nine patients treated with concurrent chemoradiation were included within the study. The initial IMRT planning (IMRTinitial) was done on the primary CT and 4DCT scan using the ITV technique. The dose was prescribed to 66 Gy in 33 fractions. After the initiation of the study weekly cone beam CT (CBCT) images were obtained before treatment. The volumes were evaluated by the treating physician in terms of target volume changes or mediastinal replacement. When adequate change was distinguished on the CBCT images an adaptive CT (CTadapt) was obtained and the volumes were recontoured by the same physician and replanned by the same physicist (IMRT adapt). Changes in lymphatic disease were not taken into account. A hybrid IMRT plan was generated to the anatomy of the CTadapt (IMRThybrid) to observe the changes occurred in critical organs such as lung, spinal cord, heart and esophagus. The dose volume histograms of the IMRTinitial versus IMRThybrid plans and IMRThybrid versus IMRT adapt were compared using paired samples t-test. Results: The median PTV volumes on initial and adaptive planning CT scans were significantly different (741 vs 414 cc; p<0.001). Significant changes were observed in lung doses between IMRTinitial and IMRThybrid (V5, 50% vs 55%; V20, 22% vs 27%; MLD 13Gy vs 15Gy; p<0.05) but these doses were significantly compensated with IMRTadapt (V5, 40%; V20, 18%; MLD, 10Gy; p<0.05). The PTV coverage significantly changed in 1 patient with mediastinal replacement. No changes were observed in other tissues. Conclusions: Repeat CT imaging and replanning during the course of IMRT for selected patients with lung cancer may help to identify dosimetric changes and to ensure safe doses to critical structures such as lung. With the implementation of adaptive treatments dose escalation may be possible in the future for improvements in clinical outcome without significant increase in toxicity. The anatomic changes seen throughout the treatment may increase the lung doses when replanning is not performed. EP-1172 Metabolic metrics in repeated FDG-PET scans show early treatment response for NSCLC patients S. Carvalho1, R. Leijenaar1, E. Rios Velazquez2, W. Van Elmpt1, C. Oberije1, E. Troost1, A. Dekker1, H. Aerts2, P. Lambin1 1 (MAASTRO), GROW – School for Oncology and Developmental Biology Maastricht University Medical Center (MUMC+), Department of Radiation Oncology, Maastricht, The Netherlands 2 Dana-Farber Cancer Institute, Department of Radiation Oncology and Radiology, Boston, USA
Results: Results for the made tests are displayed on the table. Although percentage differences of metabolic features were statistically significant in the Cox analysis, their hazard ratios reveal a nearly negligible impact on survival prediction is (HR≈1). A percentage change of the SUV threshold that encloses 70, 80 and 90% of the GTV showed a statistically significant decrease for 2-years survivors as opposed to an increase for non-survivors. The percentage difference in tumor volume above 70%SUV showed a statistical significance in splitting the two groups,with an associated decrease for survivors. For higher thresholds (80 and 90%),however, only a trend but no statistical significance was found. Similar results were also observed for relative portions of GTV above higher SUV thresholds (70% – 90%). The percentage changes in maximum mean and peak SUV were found to be significantly associated with 2-year overall survival, with a common trend of higher decrease for survivors. The percentage change in GTV showed no statistical significance between the two groups, and neither did percentage differences of possible surrogates for Metabolic Tumor Volume (MTV) based on relative (50%) and absolute (2.5 and 3) SUV thresholds.However, the percentage change of MTV defined for volume above an SUV of 4 provided a clear and significant distinction between groups.
Purpose/Objective: Non-small cell lung cancer (NSCLC) represents 80% of lung cancer incidences. Most NSCLC patients are treated with (chemo)radiotherapy,and early assessment of therapeutic response is of major importance to improve treatment outcomes. In this study we investigated the prognostic value of metabolic features of FDG-PET described by intensity-volume histograms (analogous to dose-volume histograms) acquired before and one week after (chemo)radiotherapy.We compared these metrics with commonly used predictors. We hypothesize that changes in metabolic features during the first week of (chemo)radiotherapy can be used for early response assessment. Materials and Methods: Thirty NSCLC patients (stages I-IV) underwent an FDG-PET scan before and one week after radiotherapy. Gross tumor volume (GTV) was delineated by an experienced radiation oncologist on both subsequent scans. Percentage changes of commonly used metrics (mean, maximum and peak SUV – the mean SUV inside a 1cm3 sphere centered on the maximum uptake voxel) and more complex SUV descriptors were analyzed. Univariable Cox regression was performed for overall survival assessment. Wilcoxon signed rank test was performed for 2-year overall survival (from start of radiotherapy) as outcome. A significance level of 0.05 was used.
Conclusions: We can report on the evolution of metabolic metrics based on PET images, measured as early as after the first week of radiotherapy,as being statistically significant for overall survival assessment. Further validation of these results in an extended cohort should follow these preliminary results. EP-1173 Study of offline setup error adaptive correction during radiotherapy for NSCLC based on online CBCT data L. Kong1, H. Li1, J. Cheng2, W. Huang1, B. Li1 1 Shandong Cancer Hospital and Institute, Sixth Department of Radiation Oncology, Jinan, China 2 The Second Hospital of Shandong University, Cancer Centre, Jinan, China Purpose/Objective: To investigate the systematical variations of setup errors during radiotherapy for NSCLC by analysis the online setup verification data using kilovoltage cone beam computed tomography (kV CBCT) of several fractions in a row. Then, to investigate the feasibility of using several CBCT scans to presume and correct systematic setup error for irradiation of NSCLC.
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ESTRO 33, 2014
Materials and Methods: 20 patients were recruited to investigate the systematical variations of setup errors. The means of online setup errors of 3 fractions, 4 fractions, 5 fractions in a row were calculated, and the results were used to analysis the systematical variations of setup errors. Thirty-two patients who received daily CBCT before radiation therapy had recorded shift values in the anterior-posterior, superior-inferior, and medial-lateral dimensions. The average displacements in each direction were calculated foreach patient based on the first 5 or 10 CBCT shifts and were presumed to represent the systematic setup error. The average displacements in each direction were calculated for each patient based on the first 3, 4 or 5 CBCT shifts and were presumed to represent the systematic setup error of 4 to 6, 5 to 8 and 6 to 10, the rest of the radiation was presumed using the same method. The residual error after this correction was determined by subtracting the calculated shifts from the shifts obtained using daily CBCT. The total systematic setup error, the total random setup error and the daily residual three-dimensional (3D) error were compared respectively. Results: There are systematical variations of the setup errors during radiotherapy. The extent of straggling is great in C3, C4, C5. One way analysis of variance (ANOVA) showed that no statistics difference were exited in C3, C4, C5. But there are statistics difference between C3, C4, C5 and C10. Under the condition of non-correction, the total systematic setup error were 3.20 mm, 3.32 mm, 1.96 mm, the total random setup error were 2.89 mm, 3.26 mm, 2.68mm in X, Y, and Z axis directions. Using the five CBCT corrected protocols, the total systematic setup error were 2.07 mm, 2.10 mm, 2.10 mm, the total random setup error were 2.86mm, 3.23 mm, 2.65mm in each directions. Using the 10 CBCT corrected protocols, the total systematic setup error were 2.42 mm, 2.24 mm, 2.38 mm, the total random setup error were 2.63mm, 3.06mm, 2.44mm in each directions. Using the three section IG-ART CBCT corrected protocols, the total systematic setup error were 1.65 mm, 1.48 mm,1.38 mm, the total random setup error were 3.04mm, 3.62mm, 2.83mm in each directions. Using the four section IG-ART CBCT corrected protocols, the total systematic setup error were 1.44 mm, 1.78 mm,1.62 mm, the total random setup error were 3.11mm, 3.54mm, 2.87mm in each directions. Using the five section IG-ART CBCT corrected protocols, the total systematic setup error were 1.91mm, 2.04mm, 1.70mm, the total random setup error were 2.58mm, 3.04mm, 2.61mm in each directions. Conclusions: The online CBCT correction and the approach based on offline adaptive correction both can be used to reduce the impact of setup error obviously, the required PTV margins were reduced accordingly. EP-1174 CCRT for N3-positive IIIB NSCLC: Retrospective comparison of 3D-CRT and IMRT techniques at Samsung Medical Center J.M. Noh1, Y.C. Ahn1, H. Pyo1, B. Kim1, D. Oh1, J.M. Kim1, S.G. Ju1, J.S. Kim1, J.S. Shin1, C.S. Hong1 1 Samsung Medical Center Sungkyunkwan University School of Medicine, Radiation Oncology, Seoul, Korea Republic of Purpose/Objective: This is to retrospectively evaluate clinical outcomes following definitive chemoradiotherapy (CCRT) for patients with N3positive stage IIIB non-small cell lung cancer (NSCLC) with special regard to radiation therapy (RT) techniques. Materials and Methods: From May 2010 to November 2012, 77 patients with newly diagnosed, pathologically confirmed N3-positive stage IIIB NSCLC were treated with definitive CCRT. Median age was 60 (40~80) years. The most common concurrent chemotherapy regimen was weekly docetaxel or paclitaxel plus cisplatin used in 67 patients (87.0%). RT was delivered with 4- to 10-MV photon beams, and median RT dose was 66 Gy in 33 fractions. Median clinical target volume (CTV) was 288.0 cm3, and elective irradiation to uninvolved lymphatics was not added routinely. Supraclavicular lymph nodes (SCN) were involved in 50 patients (64.9%), and 16 of them had lower lobe primary tumor. 3-dimensional conformal radiation therapy (3D-CRT) was delivered to 48 patients (62.3%), and 29 patients (37.7%), who seemed to be at excessive pulmonary toxicity risk if treated with 3D-CRT technique based on their disease extent, received intensity-modulated radiation therapy (IMRT) using step-and-shoot method. Patients receiving IMRT had significantly larger disease extent than those receiving 3D-CRT: N3 by virtue of SCN involvement and CTV ≥300 cm3 (Table). Adenocarcinoma was the most common histology in 53 patients (68.6%). Early toxicities including treatment-related pneumonitis and esophagitis were graded using CTCAE version 4.0. Infield locoregional control (LRC), progression-free survival (PFS), and overall survival (OS) were estimated by Kaplan-Meier method.
Results: After median 20.4 (2.3-41.1) months' follow-up, 44 patients (57.1%) experienced disease progression: distant metastases in 38 (49.4%); and in-field locoregional failure in eight (10.4%). 2-year LRC, PFS, and OS rates were 85.0%, 38.4%, and 74.4%, respectively. Age 3 were associated significantly worse OS (p=0.0136 and 0.0036). Incidences of toxicities were not different between RT techniques, even though patients receiving IMRT had significantly larger disease extent (Table). Conclusions: CCRT, especially in patients with larger disease extent, could have been applied more widely without excessive toxicity with technical advances in RT. However, based on significantly more frequent distant metastasis and consequent poorer outcomes in these patients, one should make optimal and cautious decision on application of IMRT technique. EP-1175 Accelerated chemo-irradiation in patients with contralateral central or mediastinal relapse after pneumonectomy C. Pöttgen1, E. Gkika1, J. Abu Jawad1, W. Lübcke1, T. Gauler2, W.E.E. Eberhardt2, G. Stamatis3, M. Stuschke1 1 Universitätsklinikum Essen, Department of Radiotherapy, Essen, Germany 2 Universitätsklinikum Essen, Department of Internal Medicine (Cancer Research), Essen, Germany 3 Universitätsklinikum Essen, Department of Thoracic Surgery Ruhrlandklinik, Essen, Germany Purpose/Objective: Treatment options for patients with contralateral central or mediastinal relapses after pneumonectomy are limited. Here we have analysed an intensified accelerated radiotherapy schedule with concurrent chemotherapy as salvage treatment after pneumonectomy (w/o previous radiotherapy). Materials and Methods: Patients with localized contralateral central intrapulmonary or mediastinal relapse after pneumonectomy were offered combined chemoradiotherapy including concurrent chemotherapy with weekly cisplatin (25 mg/m2) and accelerated radiotherapy. A total dose of 60 Gy was delivered in 8x2 Gy per week. Patients were treated in Deep-Inspiration-Breath-Hold using multifieldIMRT or helical tomotherapy in free-breething, respectively (based on 4D-CT-planning). The PTV was constructed from the ITV plus 0.5-1.0 cm safety margin, target volume coverage was 90%. Constraints to organs at risk were set within accepted limits after pneumonectomy. Image guidance during treatment was performed with on-board imaging devices and on-line cine verifications, pretreatment set-up was controlled with orthogonal portal images or cone-beam-CTs. Results: Between 10/2011 and 09/2013, eight patients were treated for tumor relapses after pneumonectomy (m/f: 7:1, median age 59 (48-73) years, stage IIB/IIIA/IIIB:2/4/2, scc/adeno/large cell histology:5/1/2) and received 60 Gy accelerated radiotherapy, 6 patients received concurrent chemotherapy, two patients refused the intended cycles of weekly cisplatin. Six patients had previous radiotherapy (30-59.4 Gy). Median dose to the remaining lung, esophagus, and spinal cord could be kept at 6.8 (3.3-11.4) Gy, 8.0 (5.1-15.5)Gy, and 7.6 (2.8-31.2) Gy, respectively. With a median follow-up of 19 (3-23) months, no clinically relevant esophageal toxicity (> grade 2 CTC) was observed. Clinical and radiographic signs of pneumonitis did not exceed grade 2CTC. Median survival was 17.2 (95%CI: 4.6;17.7) months. Local (in-field) recurrences were seen in two patients at a median time of 12 months after radiotherapy. Conclusions: This intensified chemoradiotherapy schedule was designed to minimize repopulation during therapy and to spare late effects by using conventional doses per fraction. The treatment was safely
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intensity modulated radiotherapy (IMRT) on both normal tissues and target volumes. Materials and Methods: Nine patients treated with concurrent chemoradiation were included within the study. The initial IMRT planning (IMRTinitial) was done on the primary CT and 4DCT scan using the ITV technique. The dose was prescribed to 66 Gy in 33 fractions. After the initiation of the study weekly cone beam CT (CBCT) images were obtained before treatment. The volumes were evaluated by the treating physician in terms of target volume changes or mediastinal replacement. When adequate change was distinguished on the CBCT images an adaptive CT (CTadapt) was obtained and the volumes were recontoured by the same physician and replanned by the same physicist (IMRT adapt). Changes in lymphatic disease were not taken into account. A hybrid IMRT plan was generated to the anatomy of the CTadapt (IMRThybrid) to observe the changes occurred in critical organs such as lung, spinal cord, heart and esophagus. The dose volume histograms of the IMRTinitial versus IMRThybrid plans and IMRThybrid versus IMRT adapt were compared using paired samples t-test. Results: The median PTV volumes on initial and adaptive planning CT scans were significantly different (741 vs 414 cc; p<0.001). Significant changes were observed in lung doses between IMRTinitial and IMRThybrid (V5, 50% vs 55%; V20, 22% vs 27%; MLD 13Gy vs 15Gy; p<0.05) but these doses were significantly compensated with IMRTadapt (V5, 40%; V20, 18%; MLD, 10Gy; p<0.05). The PTV coverage significantly changed in 1 patient with mediastinal replacement. No changes were observed in other tissues. Conclusions: Repeat CT imaging and replanning during the course of IMRT for selected patients with lung cancer may help to identify dosimetric changes and to ensure safe doses to critical structures such as lung. With the implementation of adaptive treatments dose escalation may be possible in the future for improvements in clinical outcome without significant increase in toxicity. The anatomic changes seen throughout the treatment may increase the lung doses when replanning is not performed. EP-1172 Metabolic metrics in repeated FDG-PET scans show early treatment response for NSCLC patients S. Carvalho1, R. Leijenaar1, E. Rios Velazquez2, W. Van Elmpt1, C. Oberije1, E. Troost1, A. Dekker1, H. Aerts2, P. Lambin1 1 (MAASTRO), GROW – School for Oncology and Developmental Biology Maastricht University Medical Center (MUMC+), Department of Radiation Oncology, Maastricht, The Netherlands 2 Dana-Farber Cancer Institute, Department of Radiation Oncology and Radiology, Boston, USA
Results: Results for the made tests are displayed on the table. Although percentage differences of metabolic features were statistically significant in the Cox analysis, their hazard ratios reveal a nearly negligible impact on survival prediction is (HR≈1). A percentage change of the SUV threshold that encloses 70, 80 and 90% of the GTV showed a statistically significant decrease for 2-years survivors as opposed to an increase for non-survivors. The percentage difference in tumor volume above 70%SUV showed a statistical significance in splitting the two groups,with an associated decrease for survivors. For higher thresholds (80 and 90%),however, only a trend but no statistical significance was found. Similar results were also observed for relative portions of GTV above higher SUV thresholds (70% – 90%). The percentage changes in maximum mean and peak SUV were found to be significantly associated with 2-year overall survival, with a common trend of higher decrease for survivors. The percentage change in GTV showed no statistical significance between the two groups, and neither did percentage differences of possible surrogates for Metabolic Tumor Volume (MTV) based on relative (50%) and absolute (2.5 and 3) SUV thresholds.However, the percentage change of MTV defined for volume above an SUV of 4 provided a clear and significant distinction between groups.
Purpose/Objective: Non-small cell lung cancer (NSCLC) represents 80% of lung cancer incidences. Most NSCLC patients are treated with (chemo)radiotherapy,and early assessment of therapeutic response is of major importance to improve treatment outcomes. In this study we investigated the prognostic value of metabolic features of FDG-PET described by intensity-volume histograms (analogous to dose-volume histograms) acquired before and one week after (chemo)radiotherapy.We compared these metrics with commonly used predictors. We hypothesize that changes in metabolic features during the first week of (chemo)radiotherapy can be used for early response assessment. Materials and Methods: Thirty NSCLC patients (stages I-IV) underwent an FDG-PET scan before and one week after radiotherapy. Gross tumor volume (GTV) was delineated by an experienced radiation oncologist on both subsequent scans. Percentage changes of commonly used metrics (mean, maximum and peak SUV – the mean SUV inside a 1cm3 sphere centered on the maximum uptake voxel) and more complex SUV descriptors were analyzed. Univariable Cox regression was performed for overall survival assessment. Wilcoxon signed rank test was performed for 2-year overall survival (from start of radiotherapy) as outcome. A significance level of 0.05 was used.
Conclusions: We can report on the evolution of metabolic metrics based on PET images, measured as early as after the first week of radiotherapy,as being statistically significant for overall survival assessment. Further validation of these results in an extended cohort should follow these preliminary results. EP-1173 Study of offline setup error adaptive correction during radiotherapy for NSCLC based on online CBCT data L. Kong1, H. Li1, J. Cheng2, W. Huang1, B. Li1 1 Shandong Cancer Hospital and Institute, Sixth Department of Radiation Oncology, Jinan, China 2 The Second Hospital of Shandong University, Cancer Centre, Jinan, China Purpose/Objective: To investigate the systematical variations of setup errors during radiotherapy for NSCLC by analysis the online setup verification data using kilovoltage cone beam computed tomography (kV CBCT) of several fractions in a row. Then, to investigate the feasibility of using several CBCT scans to presume and correct systematic setup error for irradiation of NSCLC.
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ESTRO 33, 2014
Materials and Methods: 20 patients were recruited to investigate the systematical variations of setup errors. The means of online setup errors of 3 fractions, 4 fractions, 5 fractions in a row were calculated, and the results were used to analysis the systematical variations of setup errors. Thirty-two patients who received daily CBCT before radiation therapy had recorded shift values in the anterior-posterior, superior-inferior, and medial-lateral dimensions. The average displacements in each direction were calculated foreach patient based on the first 5 or 10 CBCT shifts and were presumed to represent the systematic setup error. The average displacements in each direction were calculated for each patient based on the first 3, 4 or 5 CBCT shifts and were presumed to represent the systematic setup error of 4 to 6, 5 to 8 and 6 to 10, the rest of the radiation was presumed using the same method. The residual error after this correction was determined by subtracting the calculated shifts from the shifts obtained using daily CBCT. The total systematic setup error, the total random setup error and the daily residual three-dimensional (3D) error were compared respectively. Results: There are systematical variations of the setup errors during radiotherapy. The extent of straggling is great in C3, C4, C5. One way analysis of variance (ANOVA) showed that no statistics difference were exited in C3, C4, C5. But there are statistics difference between C3, C4, C5 and C10. Under the condition of non-correction, the total systematic setup error were 3.20 mm, 3.32 mm, 1.96 mm, the total random setup error were 2.89 mm, 3.26 mm, 2.68mm in X, Y, and Z axis directions. Using the five CBCT corrected protocols, the total systematic setup error were 2.07 mm, 2.10 mm, 2.10 mm, the total random setup error were 2.86mm, 3.23 mm, 2.65mm in each directions. Using the 10 CBCT corrected protocols, the total systematic setup error were 2.42 mm, 2.24 mm, 2.38 mm, the total random setup error were 2.63mm, 3.06mm, 2.44mm in each directions. Using the three section IG-ART CBCT corrected protocols, the total systematic setup error were 1.65 mm, 1.48 mm,1.38 mm, the total random setup error were 3.04mm, 3.62mm, 2.83mm in each directions. Using the four section IG-ART CBCT corrected protocols, the total systematic setup error were 1.44 mm, 1.78 mm,1.62 mm, the total random setup error were 3.11mm, 3.54mm, 2.87mm in each directions. Using the five section IG-ART CBCT corrected protocols, the total systematic setup error were 1.91mm, 2.04mm, 1.70mm, the total random setup error were 2.58mm, 3.04mm, 2.61mm in each directions. Conclusions: The online CBCT correction and the approach based on offline adaptive correction both can be used to reduce the impact of setup error obviously, the required PTV margins were reduced accordingly. EP-1174 CCRT for N3-positive IIIB NSCLC: Retrospective comparison of 3D-CRT and IMRT techniques at Samsung Medical Center J.M. Noh1, Y.C. Ahn1, H. Pyo1, B. Kim1, D. Oh1, J.M. Kim1, S.G. Ju1, J.S. Kim1, J.S. Shin1, C.S. Hong1 1 Samsung Medical Center Sungkyunkwan University School of Medicine, Radiation Oncology, Seoul, Korea Republic of Purpose/Objective: This is to retrospectively evaluate clinical outcomes following definitive chemoradiotherapy (CCRT) for patients with N3positive stage IIIB non-small cell lung cancer (NSCLC) with special regard to radiation therapy (RT) techniques. Materials and Methods: From May 2010 to November 2012, 77 patients with newly diagnosed, pathologically confirmed N3-positive stage IIIB NSCLC were treated with definitive CCRT. Median age was 60 (40~80) years. The most common concurrent chemotherapy regimen was weekly docetaxel or paclitaxel plus cisplatin used in 67 patients (87.0%). RT was delivered with 4- to 10-MV photon beams, and median RT dose was 66 Gy in 33 fractions. Median clinical target volume (CTV) was 288.0 cm3, and elective irradiation to uninvolved lymphatics was not added routinely. Supraclavicular lymph nodes (SCN) were involved in 50 patients (64.9%), and 16 of them had lower lobe primary tumor. 3-dimensional conformal radiation therapy (3D-CRT) was delivered to 48 patients (62.3%), and 29 patients (37.7%), who seemed to be at excessive pulmonary toxicity risk if treated with 3D-CRT technique based on their disease extent, received intensity-modulated radiation therapy (IMRT) using step-and-shoot method. Patients receiving IMRT had significantly larger disease extent than those receiving 3D-CRT: N3 by virtue of SCN involvement and CTV ≥300 cm3 (Table). Adenocarcinoma was the most common histology in 53 patients (68.6%). Early toxicities including treatment-related pneumonitis and esophagitis were graded using CTCAE version 4.0. Infield locoregional control (LRC), progression-free survival (PFS), and overall survival (OS) were estimated by Kaplan-Meier method.
Results: After median 20.4 (2.3-41.1) months' follow-up, 44 patients (57.1%) experienced disease progression: distant metastases in 38 (49.4%); and in-field locoregional failure in eight (10.4%). 2-year LRC, PFS, and OS rates were 85.0%, 38.4%, and 74.4%, respectively. Age 3 were associated significantly worse OS (p=0.0136 and 0.0036). Incidences of toxicities were not different between RT techniques, even though patients receiving IMRT had significantly larger disease extent (Table). Conclusions: CCRT, especially in patients with larger disease extent, could have been applied more widely without excessive toxicity with technical advances in RT. However, based on significantly more frequent distant metastasis and consequent poorer outcomes in these patients, one should make optimal and cautious decision on application of IMRT technique. EP-1175 Accelerated chemo-irradiation in patients with contralateral central or mediastinal relapse after pneumonectomy C. Pöttgen1, E. Gkika1, J. Abu Jawad1, W. Lübcke1, T. Gauler2, W.E.E. Eberhardt2, G. Stamatis3, M. Stuschke1 1 Universitätsklinikum Essen, Department of Radiotherapy, Essen, Germany 2 Universitätsklinikum Essen, Department of Internal Medicine (Cancer Research), Essen, Germany 3 Universitätsklinikum Essen, Department of Thoracic Surgery Ruhrlandklinik, Essen, Germany Purpose/Objective: Treatment options for patients with contralateral central or mediastinal relapses after pneumonectomy are limited. Here we have analysed an intensified accelerated radiotherapy schedule with concurrent chemotherapy as salvage treatment after pneumonectomy (w/o previous radiotherapy). Materials and Methods: Patients with localized contralateral central intrapulmonary or mediastinal relapse after pneumonectomy were offered combined chemoradiotherapy including concurrent chemotherapy with weekly cisplatin (25 mg/m2) and accelerated radiotherapy. A total dose of 60 Gy was delivered in 8x2 Gy per week. Patients were treated in Deep-Inspiration-Breath-Hold using multifieldIMRT or helical tomotherapy in free-breething, respectively (based on 4D-CT-planning). The PTV was constructed from the ITV plus 0.5-1.0 cm safety margin, target volume coverage was 90%. Constraints to organs at risk were set within accepted limits after pneumonectomy. Image guidance during treatment was performed with on-board imaging devices and on-line cine verifications, pretreatment set-up was controlled with orthogonal portal images or cone-beam-CTs. Results: Between 10/2011 and 09/2013, eight patients were treated for tumor relapses after pneumonectomy (m/f: 7:1, median age 59 (48-73) years, stage IIB/IIIA/IIIB:2/4/2, scc/adeno/large cell histology:5/1/2) and received 60 Gy accelerated radiotherapy, 6 patients received concurrent chemotherapy, two patients refused the intended cycles of weekly cisplatin. Six patients had previous radiotherapy (30-59.4 Gy). Median dose to the remaining lung, esophagus, and spinal cord could be kept at 6.8 (3.3-11.4) Gy, 8.0 (5.1-15.5)Gy, and 7.6 (2.8-31.2) Gy, respectively. With a median follow-up of 19 (3-23) months, no clinically relevant esophageal toxicity (> grade 2 CTC) was observed. Clinical and radiographic signs of pneumonitis did not exceed grade 2CTC. Median survival was 17.2 (95%CI: 4.6;17.7) months. Local (in-field) recurrences were seen in two patients at a median time of 12 months after radiotherapy. Conclusions: This intensified chemoradiotherapy schedule was designed to minimize repopulation during therapy and to spare late effects by using conventional doses per fraction. The treatment was safely