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Role of Stereotactic Body Radiation Therapy With Volumetric Modulated Arc Therapy Technique and FFF Beams for Abdomino-Pelvic Lymph Node Metastases in Oligometastatic Patients
E142
International Journal of Radiation Oncology Biology Physics
Conclusion: cT4 group showed good curative resection (R0) rate, OS and LRC. Neoadjuvant CRT followed by surgery should be an effective treatment option for patients with initially inoperable cT4 thoracic esophageal cancer, when a primary tumor decreases in size and down-stage is obtained. Author Disclosure: H. Morimoto: None. Y. Fujiwara: None. M. Hosono: None. S. Matsuda: None. K. Amano: None. E. Okazaki: None. Y. Miki: None. S. Tsutsumi: None. H. Osugi: None. Y. Miki: None.
be an independent prognostic factor for advanced esophageal squamous cell carcinoma. Author Disclosure: N. Takahashi: None.
2346 Pretreatment Metabolic Tumor Volume on FDG-PET/CT Is an Independent Prognostic Factor for OS, LC, and PFS in Patients With Clinical Stage III Esophageal Squamous Cell Carcinoma Treated with Definitive Chemoradiation Therapy N. Takahashi; Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan Purpose/Objective(s): The aim of this study was to determine whether pretreatment metabolic tumor volume (MTV) is associated with overall survival (OS), local control (LC) and progression-free survival (PFS) in patients with clinical stage III esophageal squamous cell carcinoma treated with definitive chemoradiation therapy. Materials/Methods: Eighty-two patients were selected for this study. They underwent FDG-PET/CT within 60 days before definitive chemoradiation therapy (dCRT) at our institution between January 2005 and December 2013. Patients who underwent FDG-PET at another institution and patients who had massive pneumonia caused by perforation of the tumor were excluded. We calculated MTV3 and MTV40% at pretreatment FDG-PET/CT. Survival estimates were calculated using the KaplanMeier method from the first date of dCRT. Prognostic factors for OS, LC, and PFS were analyzed using Cox’s proportional hazards model. Cut-off values of MTV3 and MTV40% were set to 27 cm3 and 12 cm3, respectively, by reference to receiver operating characteristic curves for OS, LC, and PFS. Results: The median follow-up period for all patients was 19.8 months and the median follow-up period for survivors was 36.3 months. Two-year OS, LC, and PES rates were 54.5%, 47.5% and 32.3%, respectively. Five-year OS, LC, and PFS rates were 38.6%, 47.5% and 32.3%, respectively. In univariate analyses, MTV40% median value (P Z 0.041) and MTV40% cut-off value (P Z 0.017) were significant predictors for OS. MTV3 cutoff value (P Z 0.041) and MTV40% cut-off value (P Z 0.035) were significant predictors for LC. MTV40% cut-off value (P Z 0.017) was a significant predictor for PFS. MTV3 and MTV40% were highly correlated. Therefore, MTVX were separately analyzed in multivariate analyses. We included factors with P < 0.2 in univariate analyses in multivariate analyses. T stage, gender, number of concurrent chemotherapy courses and MTVX were included in multivariate analyses for OS and PFS. T stage, number of concurrent chemotherapy courses and MTVX were included in multivariate analyses for LC. In multivariate analyses, MTV40% median value (P Z 0.047) and MTV40% cut-off value (P Z 0.028) were significant predictors for OS. MTV3 cut-off value (P Z 0.041) was a significant predictor for LC. MTV40% cut-off value (P Z 0.045) was a significant predictor for PFS. Conclusion: MTV40% was an independent prognostic factor for OS and PFS, and MTV3was an independent prognostic factor for LC. MTV might
Abstract 2346; Table 1. Multivariate analyses for OS, LC, and PFS. P value Variables Gender (male vs female) T4 vs T3 Chemo 2 cycles vs 1 cycle MTV40% median vs > median MTV40% cut off vs > cut off MTV3 cut off vs > cut off
OS
OS
LC
PFS
0.104 0.023* 0.135 0.047* -
0.108 0.016* 0.220 0.028* -
-0.343 0.022* 0.033*
0.075 0.008* 0.075 0.045* -
2347 Impact of Sarcopenia Evaluated Using the Total Psoas Area (TPA) in Patient Undergoing Y-90 Radioembolization for Hepatocellular Carcinoma (HCC) P. Ioannides,1 Y.A. Abuodeh,2 W. Jin,3 S.E. Hoffe,2 J.M. Frakes,2 R. Kim,4 J. Choi,2 G. El-Hadda,4 B. Biebel,2 B. Kis,2 J. Sweeney,2 M. Friedman,4 N. Kothari,4 D. Anaya,4 and K. Latifi2; 1Indiana University School of Medicine, Indianapolis, IN, 2H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, 3USF, Tampa, FL, 4Moffitt Cancer Center, Tampa, FL Purpose/Objective(s): Severe skeletal muscle depletion, or sarcopenia, is an independent predictor of clinical outcomes in multiple gastrointestinal cancers. This marker of nutritional status has been defined using the TPA which is measured on a single cross sectional CT image at the L4 vertebral body level. We sought to evaluate whether TPA was predictive of outcomes in those patients with unresectable HCC receiving Y-90 radioembolization. Materials/Methods: In an IRB approved database consisting of HCC patients treated with Y-90 radioembolization, 111 patients met our selection criteria of treatment from 2009-2014. To be eligible for the study, patients were included prior to their first injection of Y-90 if they had CT imaging available that included the L4 vertebral level that could be transferred to the treatment planning software system. Of these, 73 patients met criteria and were included in the final analysis. The L4 vertebra was identified on axial CT imaging and the psoas muscle was manually contoured bilaterally. Sarcopenia was defined by the presence of the psoas area in less than the median of the cohort. Results: Sarcopenia was associated with a significantly decreased overall survival (P Z 0.013). The mean age of the cohort was 67.6 years (SD, +/9.45) consisting of 84% male and 16% female patients. Difference in age or gender did not correlate significantly with survival. The median survival time in the “low” (sarcopenic) group was 10.46 months (SD, +/- 1.21), whereas the median survival in the “high” group was 18.02 months (SD, +/-4.26). The median survival for the entire cohort was 12.86 months. OS at 30 months was 15.4% in the sarcopenic group and 30.2% in the “high” group. TPA in the upper quartile was associated with a survival benefit compared to the bottom quartiles. The presence of sarcopenia was associated with an increased risk of mortality (HR Z 2.049; P Z 0.015 CI: 01.150, 3.649). Conclusion: Measurement of the psoas area using TPA is a simple objective method to detect frailty and is predictive of overall survival outcome following Y-90 radioembolization. Author Disclosure: P. Ioannides: None. Y.A. Abuodeh: None. W. Jin: None. S.E. Hoffe: None. J.M. Frakes: None. R. Kim: None. J. Choi: None. G. El-Hadda: None. B. Biebel: None. B. Kis: None. J. Sweeney: None. M. Friedman: None. N. Kothari: None. D. Anaya: None. K. Latifi: None.
2348 Role of Stereotactic Body Radiation Therapy With Volumetric Modulated Arc Therapy Technique and FFF Beams for AbdominoPelvic Lymph Node Metastases in Oligometastatic Patients C. Franzese,1 L. Cozzi,1,2 E. Clerici,2 G.R. D’Agostino,2 P. Navarria,1 T. Comito,1 F. De Rose,1 A.M. Ascolese,1 D. Franceschini,2 P. Mancosu,3 S. Tomatis,1 and M. Scorsetti1; 1Humanitas Cancer Center and Research Hospital, Rozzano, Italy, 2Humanitas Clinical and Research Hospital, Rozzano, Italy, 3Humanitas Cancer Center, Rozzano, Italy Purpose/Objective(s): Nowadays stereotactic body radiation therapy (SBRT) is considered a safe and effective approach for several sites of metastatic disease. So far, few published data exist on local control rates of
Volume 96 Number 2S Supplement 2016 radiation therapy in the context of isolated or limited lymph node metastases. We analyzed the dosimetric and clinical results of oligometastatic patients treated with SBRT for isolated lymph node metastases in abdomen and/or pelvis. Materials/Methods: In the analysis we included patients with a maximum of 5 lymph node sites of disease with diameter less than 5 cm, located in the abdomen or pelvis. Radiation therapy was administered with Volumetric Modulated Arc Therapy Rapid-Arc (VMAT-RA) and flattening filter-free (FFF) beams; prescribed dose was 45 Gy in 6 fractions of 7.5 Gy each. We analyzed dosimetric data and correlated them with acute toxicity (CTCAE 3.0), local and distant control of disease, progression free survival, and overall survival. Results: From January 2006 to May 2015, we treated 97 patients with lymph node metastases, of which 26 were lost at follow-up. We analyzed than 71 patients with a total of 79 treated lesions, with a mean follow-up of 1.44 years (range 0.14 e 6.21 years). At revaluation, complete response was achieved in 39 (49.3%) lesions and partial response in 28 (35.4%) lesions. Stable disease was demonstrated in 10 (12.6%) cases while only 2 (2.5%) lesions showed progression of disease. The overall clinical benefit rate was 97.5% (77/79 lesions). Acute toxicity was mild: 10 (14%) patients reported G1 toxicity (notably nausea and fatigue); 2 (2.8%) patients reported G2 toxicity (nausea and diarrhea). No Grade 3 and 4 toxicities were reported. In-field progression of disease during follow-up was demonstrated in 18 sites (22.7%) with a median time of 10.7 months. Out-field lymph node progression was demonstrated in 22 (27.8%) cases while distant metastases occurred in 25 (31.6%) cases. Local control rate and overall survival rate at 1 year were 83% and 93%, respectively. Conclusion: In consideration of our dosimetric and clinical results, SBRT with VMAT-RA and FFF beams can be considered a safe and effective approach in oligometastatic patients with abdomino-pelvic isolated lymph node metastases. Although this can be considered an initial experience, these results may be potentially significant for preserving quality of life of patients and delaying further systemic treatments. Author Disclosure: C. Franzese: None. L. Cozzi: None. E. Clerici: None. G. D’Agostino: None. P. Navarria: None. T. Comito: None. F. De Rose: None. A. Ascolese: None. D. Franceschini: None. P. Mancosu: None. S. Tomatis: None. M. Scorsetti: None.
2349 Adjuvant Chemoradiation for Resected Gallbladder Cancer: Single-Center 25-Year Experience C.V. Sole, V. Sole, and S. Sole; Clinica Instituto de Radiomedicina (IRAM), Santiago, Chile Purpose/Objective(s): Patients with locally advanced gallbladder cancer (LAGC) have a dismal prognosis. We investigated outcomes and risk factors for overall survival (OS) in patients treated with radical surgery and adjuvant chemoradiation therapy (CRT). Materials/Methods: A total of 212 patients with LAGC [cT3 59% and/ or cN+ 52%) were studied. The primary endpoint of the analysis was OS. The KaplaneMeier method was used to estimate the probabilities of OS. For survival outcomes potential associations were assessed in univariate and multivariate analyses using the Cox proportional hazards model. We constructed a risk scoring system in which points were assigned to each risk factor by dividing each ß coefficient in the final model by the lowest ß coefficient and rounding to the nearest integer. A risk score was assigned to each subject by adding up the points for each risk factor present. Subjects were then divided into three risk groups based on their risk scores (0 points Z low risk, 1-2 points Z intermediate risk, 3-6 points Z high risk). Results: Median follow-up was 46.2 months (2-235). Five-year OS for the entire cohort was 50.2%. In multivariate analysis higher pT stage [HR: 2.43 (1.29-3.68), P Z 0.01], R1 resection [HR 5.06 (3.12-8.19), P < 0.001], and number of surgical procedures [HR 1.41 (1.01-2.16),
Poster Viewing E143 P Z 0.05] were associated with an increased risk of death. Five-year OS for patients with low (n Z 63), intermediate (n Z 94) and high (n Z 55) risk was 79.1%, 59.2% and 9.5%, respectively. Conclusion: Overall results after multimodality treatment of LAGC are promising. A risk model was generated to determine a prognostic index for individual patients with LAGC. Classification of risk factors for death has contributed to propose a prognostic index that could allow us to guide riskadapted tailored treatment. Author Disclosure: C.V. Sole: None. V. Sole: None. S. Sole: None.
2350 Prognostic Value of Nodal SUVmax of Pretreatment FDG Positron Emission Tomography Imaging in Patients With Esophageal Cancer W.K. Yap, T.M. Hung, C.K. Tseng, and Y.C. Chang; Chang Gung Memorial Hospital, Taoyuan, Taiwan Purpose/Objective(s): To assess whether the pretreatment [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) maximum standardized uptake value (SUVmax) of metastatic lymph nodes can predict the prognosis of patients with esophageal cancer and can select patients who may not benefit from planned esophagectomy after chemoradiation. Materials/Methods: We retrospectively reviewed electronic medical records of 102 patients with histologically confirmed stage IIA to IIIC esophageal cancer (97.1% squamous cell carcinoma, 96.1% stage III) receiving chemoradiation therapy with or without resection. All patients received an initial FDG-PET for staging purposes. All patients received surgical evaluation after first course of chemoradiation therapy. Primary tumor SUVmax and metastatic lymph node SUVmax were separately recorded and the best cut-off value for survival analyses were determined by log-rank test and receiver operating characteristic (ROC) curve analysis. The influence of clinicopathological factors including primary tumor SUVmax and nodal SUVmax on freedom from local failure (LFF), freedom from nodal failure (NFF), freedom from distant failure (DFF), overall survival (OS) and progression-free survival (PFS) were evaluated using univariate and multivariate analysis. Results: Forty patients received trimodality therapy and 62 received definitive chemoradiotherapy (dCRT). Patients receiving trimodality therapy had better outcomes than patients receiving dCRT (2-year OS, 71% v 34%, P Z .001; 2-year PFS, 45% v 17%, P Z .0001; 2-year LFF, 89% v 39%, P Z .0001; 2-year NFF, 78% v 50%, P Z .004; 2-year DFF, 70% v 50%, P Z .054). Nodal SUVmax <7 predicted for improved outcomes for dCRT (2-year DFF, 92% v 17%, P Z .0001; 2-year RFF, 81% v 14%, P Z .001; 2-year OS, 50% v 21%, P Z .003; 2-year PFS, 36% v 3%, P Z .001; No significant difference in LFF), but not trimodality therapy. Primary tumor SUVmax <18.67 only predicted for better 2-year DFF (59% v 37%, P Z .005) for dCRT, but not trimodality therapy. Compared to patients receiving trimodality, patients receiving dCRT with nodal SUVmax <7 were not different on OS (P Z .22), PFS (P Z .17), DFF (P Z .19) and NFF (P Z .60) despite having more advanced disease at baseline, but did worse on LFF (P Z .002); Patients receiving dCRT with nodal SUVmax >7 did significantly worse in OS (P Z .0001), PFS (P Z .0001), DFF (P Z .0001), NFF (P Z .0001) and LFF (P Z .0001) comparing to patients receiving trimodality. On multivariate analysis of patients receiving dCRT, nodal SUVmax <7 is the strongest independent prognostic variable (OS hazard ratio [HR], 3.08 P Z .002; PFS HR, 2.17 P Z .018; DFF HR, 8.33 P Z .002; NFF HR, 3.55 P Z .025). Conclusion: Pretreatment nodal SUVmax was a strong prognostic indicator on nodal failure, distant failure, progression free survival, and overall survival for patients receiving definitive chemoradiotherapy. Planned esophagectomy only improved local control but not nodal control, distant failure and survivals in patients whose pretreatment nodal SUVmax <7. Author Disclosure: W. Yap: None. T. Hung: None. C. Tseng: None. Y. Chang: None.
International Journal of Radiation Oncology Biology Physics
Conclusion: cT4 group showed good curative resection (R0) rate, OS and LRC. Neoadjuvant CRT followed by surgery should be an effective treatment option for patients with initially inoperable cT4 thoracic esophageal cancer, when a primary tumor decreases in size and down-stage is obtained. Author Disclosure: H. Morimoto: None. Y. Fujiwara: None. M. Hosono: None. S. Matsuda: None. K. Amano: None. E. Okazaki: None. Y. Miki: None. S. Tsutsumi: None. H. Osugi: None. Y. Miki: None.
be an independent prognostic factor for advanced esophageal squamous cell carcinoma. Author Disclosure: N. Takahashi: None.
2346 Pretreatment Metabolic Tumor Volume on FDG-PET/CT Is an Independent Prognostic Factor for OS, LC, and PFS in Patients With Clinical Stage III Esophageal Squamous Cell Carcinoma Treated with Definitive Chemoradiation Therapy N. Takahashi; Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan Purpose/Objective(s): The aim of this study was to determine whether pretreatment metabolic tumor volume (MTV) is associated with overall survival (OS), local control (LC) and progression-free survival (PFS) in patients with clinical stage III esophageal squamous cell carcinoma treated with definitive chemoradiation therapy. Materials/Methods: Eighty-two patients were selected for this study. They underwent FDG-PET/CT within 60 days before definitive chemoradiation therapy (dCRT) at our institution between January 2005 and December 2013. Patients who underwent FDG-PET at another institution and patients who had massive pneumonia caused by perforation of the tumor were excluded. We calculated MTV3 and MTV40% at pretreatment FDG-PET/CT. Survival estimates were calculated using the KaplanMeier method from the first date of dCRT. Prognostic factors for OS, LC, and PFS were analyzed using Cox’s proportional hazards model. Cut-off values of MTV3 and MTV40% were set to 27 cm3 and 12 cm3, respectively, by reference to receiver operating characteristic curves for OS, LC, and PFS. Results: The median follow-up period for all patients was 19.8 months and the median follow-up period for survivors was 36.3 months. Two-year OS, LC, and PES rates were 54.5%, 47.5% and 32.3%, respectively. Five-year OS, LC, and PFS rates were 38.6%, 47.5% and 32.3%, respectively. In univariate analyses, MTV40% median value (P Z 0.041) and MTV40% cut-off value (P Z 0.017) were significant predictors for OS. MTV3 cutoff value (P Z 0.041) and MTV40% cut-off value (P Z 0.035) were significant predictors for LC. MTV40% cut-off value (P Z 0.017) was a significant predictor for PFS. MTV3 and MTV40% were highly correlated. Therefore, MTVX were separately analyzed in multivariate analyses. We included factors with P < 0.2 in univariate analyses in multivariate analyses. T stage, gender, number of concurrent chemotherapy courses and MTVX were included in multivariate analyses for OS and PFS. T stage, number of concurrent chemotherapy courses and MTVX were included in multivariate analyses for LC. In multivariate analyses, MTV40% median value (P Z 0.047) and MTV40% cut-off value (P Z 0.028) were significant predictors for OS. MTV3 cut-off value (P Z 0.041) was a significant predictor for LC. MTV40% cut-off value (P Z 0.045) was a significant predictor for PFS. Conclusion: MTV40% was an independent prognostic factor for OS and PFS, and MTV3was an independent prognostic factor for LC. MTV might
Abstract 2346; Table 1. Multivariate analyses for OS, LC, and PFS. P value Variables Gender (male vs female) T4 vs T3 Chemo 2 cycles vs 1 cycle MTV40% median vs > median MTV40% cut off vs > cut off MTV3 cut off vs > cut off
OS
OS
LC
PFS
0.104 0.023* 0.135 0.047* -
0.108 0.016* 0.220 0.028* -
-0.343 0.022* 0.033*
0.075 0.008* 0.075 0.045* -
2347 Impact of Sarcopenia Evaluated Using the Total Psoas Area (TPA) in Patient Undergoing Y-90 Radioembolization for Hepatocellular Carcinoma (HCC) P. Ioannides,1 Y.A. Abuodeh,2 W. Jin,3 S.E. Hoffe,2 J.M. Frakes,2 R. Kim,4 J. Choi,2 G. El-Hadda,4 B. Biebel,2 B. Kis,2 J. Sweeney,2 M. Friedman,4 N. Kothari,4 D. Anaya,4 and K. Latifi2; 1Indiana University School of Medicine, Indianapolis, IN, 2H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, 3USF, Tampa, FL, 4Moffitt Cancer Center, Tampa, FL Purpose/Objective(s): Severe skeletal muscle depletion, or sarcopenia, is an independent predictor of clinical outcomes in multiple gastrointestinal cancers. This marker of nutritional status has been defined using the TPA which is measured on a single cross sectional CT image at the L4 vertebral body level. We sought to evaluate whether TPA was predictive of outcomes in those patients with unresectable HCC receiving Y-90 radioembolization. Materials/Methods: In an IRB approved database consisting of HCC patients treated with Y-90 radioembolization, 111 patients met our selection criteria of treatment from 2009-2014. To be eligible for the study, patients were included prior to their first injection of Y-90 if they had CT imaging available that included the L4 vertebral level that could be transferred to the treatment planning software system. Of these, 73 patients met criteria and were included in the final analysis. The L4 vertebra was identified on axial CT imaging and the psoas muscle was manually contoured bilaterally. Sarcopenia was defined by the presence of the psoas area in less than the median of the cohort. Results: Sarcopenia was associated with a significantly decreased overall survival (P Z 0.013). The mean age of the cohort was 67.6 years (SD, +/9.45) consisting of 84% male and 16% female patients. Difference in age or gender did not correlate significantly with survival. The median survival time in the “low” (sarcopenic) group was 10.46 months (SD, +/- 1.21), whereas the median survival in the “high” group was 18.02 months (SD, +/-4.26). The median survival for the entire cohort was 12.86 months. OS at 30 months was 15.4% in the sarcopenic group and 30.2% in the “high” group. TPA in the upper quartile was associated with a survival benefit compared to the bottom quartiles. The presence of sarcopenia was associated with an increased risk of mortality (HR Z 2.049; P Z 0.015 CI: 01.150, 3.649). Conclusion: Measurement of the psoas area using TPA is a simple objective method to detect frailty and is predictive of overall survival outcome following Y-90 radioembolization. Author Disclosure: P. Ioannides: None. Y.A. Abuodeh: None. W. Jin: None. S.E. Hoffe: None. J.M. Frakes: None. R. Kim: None. J. Choi: None. G. El-Hadda: None. B. Biebel: None. B. Kis: None. J. Sweeney: None. M. Friedman: None. N. Kothari: None. D. Anaya: None. K. Latifi: None.
2348 Role of Stereotactic Body Radiation Therapy With Volumetric Modulated Arc Therapy Technique and FFF Beams for AbdominoPelvic Lymph Node Metastases in Oligometastatic Patients C. Franzese,1 L. Cozzi,1,2 E. Clerici,2 G.R. D’Agostino,2 P. Navarria,1 T. Comito,1 F. De Rose,1 A.M. Ascolese,1 D. Franceschini,2 P. Mancosu,3 S. Tomatis,1 and M. Scorsetti1; 1Humanitas Cancer Center and Research Hospital, Rozzano, Italy, 2Humanitas Clinical and Research Hospital, Rozzano, Italy, 3Humanitas Cancer Center, Rozzano, Italy Purpose/Objective(s): Nowadays stereotactic body radiation therapy (SBRT) is considered a safe and effective approach for several sites of metastatic disease. So far, few published data exist on local control rates of
Volume 96 Number 2S Supplement 2016 radiation therapy in the context of isolated or limited lymph node metastases. We analyzed the dosimetric and clinical results of oligometastatic patients treated with SBRT for isolated lymph node metastases in abdomen and/or pelvis. Materials/Methods: In the analysis we included patients with a maximum of 5 lymph node sites of disease with diameter less than 5 cm, located in the abdomen or pelvis. Radiation therapy was administered with Volumetric Modulated Arc Therapy Rapid-Arc (VMAT-RA) and flattening filter-free (FFF) beams; prescribed dose was 45 Gy in 6 fractions of 7.5 Gy each. We analyzed dosimetric data and correlated them with acute toxicity (CTCAE 3.0), local and distant control of disease, progression free survival, and overall survival. Results: From January 2006 to May 2015, we treated 97 patients with lymph node metastases, of which 26 were lost at follow-up. We analyzed than 71 patients with a total of 79 treated lesions, with a mean follow-up of 1.44 years (range 0.14 e 6.21 years). At revaluation, complete response was achieved in 39 (49.3%) lesions and partial response in 28 (35.4%) lesions. Stable disease was demonstrated in 10 (12.6%) cases while only 2 (2.5%) lesions showed progression of disease. The overall clinical benefit rate was 97.5% (77/79 lesions). Acute toxicity was mild: 10 (14%) patients reported G1 toxicity (notably nausea and fatigue); 2 (2.8%) patients reported G2 toxicity (nausea and diarrhea). No Grade 3 and 4 toxicities were reported. In-field progression of disease during follow-up was demonstrated in 18 sites (22.7%) with a median time of 10.7 months. Out-field lymph node progression was demonstrated in 22 (27.8%) cases while distant metastases occurred in 25 (31.6%) cases. Local control rate and overall survival rate at 1 year were 83% and 93%, respectively. Conclusion: In consideration of our dosimetric and clinical results, SBRT with VMAT-RA and FFF beams can be considered a safe and effective approach in oligometastatic patients with abdomino-pelvic isolated lymph node metastases. Although this can be considered an initial experience, these results may be potentially significant for preserving quality of life of patients and delaying further systemic treatments. Author Disclosure: C. Franzese: None. L. Cozzi: None. E. Clerici: None. G. D’Agostino: None. P. Navarria: None. T. Comito: None. F. De Rose: None. A. Ascolese: None. D. Franceschini: None. P. Mancosu: None. S. Tomatis: None. M. Scorsetti: None.
2349 Adjuvant Chemoradiation for Resected Gallbladder Cancer: Single-Center 25-Year Experience C.V. Sole, V. Sole, and S. Sole; Clinica Instituto de Radiomedicina (IRAM), Santiago, Chile Purpose/Objective(s): Patients with locally advanced gallbladder cancer (LAGC) have a dismal prognosis. We investigated outcomes and risk factors for overall survival (OS) in patients treated with radical surgery and adjuvant chemoradiation therapy (CRT). Materials/Methods: A total of 212 patients with LAGC [cT3 59% and/ or cN+ 52%) were studied. The primary endpoint of the analysis was OS. The KaplaneMeier method was used to estimate the probabilities of OS. For survival outcomes potential associations were assessed in univariate and multivariate analyses using the Cox proportional hazards model. We constructed a risk scoring system in which points were assigned to each risk factor by dividing each ß coefficient in the final model by the lowest ß coefficient and rounding to the nearest integer. A risk score was assigned to each subject by adding up the points for each risk factor present. Subjects were then divided into three risk groups based on their risk scores (0 points Z low risk, 1-2 points Z intermediate risk, 3-6 points Z high risk). Results: Median follow-up was 46.2 months (2-235). Five-year OS for the entire cohort was 50.2%. In multivariate analysis higher pT stage [HR: 2.43 (1.29-3.68), P Z 0.01], R1 resection [HR 5.06 (3.12-8.19), P < 0.001], and number of surgical procedures [HR 1.41 (1.01-2.16),
Poster Viewing E143 P Z 0.05] were associated with an increased risk of death. Five-year OS for patients with low (n Z 63), intermediate (n Z 94) and high (n Z 55) risk was 79.1%, 59.2% and 9.5%, respectively. Conclusion: Overall results after multimodality treatment of LAGC are promising. A risk model was generated to determine a prognostic index for individual patients with LAGC. Classification of risk factors for death has contributed to propose a prognostic index that could allow us to guide riskadapted tailored treatment. Author Disclosure: C.V. Sole: None. V. Sole: None. S. Sole: None.
2350 Prognostic Value of Nodal SUVmax of Pretreatment FDG Positron Emission Tomography Imaging in Patients With Esophageal Cancer W.K. Yap, T.M. Hung, C.K. Tseng, and Y.C. Chang; Chang Gung Memorial Hospital, Taoyuan, Taiwan Purpose/Objective(s): To assess whether the pretreatment [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) maximum standardized uptake value (SUVmax) of metastatic lymph nodes can predict the prognosis of patients with esophageal cancer and can select patients who may not benefit from planned esophagectomy after chemoradiation. Materials/Methods: We retrospectively reviewed electronic medical records of 102 patients with histologically confirmed stage IIA to IIIC esophageal cancer (97.1% squamous cell carcinoma, 96.1% stage III) receiving chemoradiation therapy with or without resection. All patients received an initial FDG-PET for staging purposes. All patients received surgical evaluation after first course of chemoradiation therapy. Primary tumor SUVmax and metastatic lymph node SUVmax were separately recorded and the best cut-off value for survival analyses were determined by log-rank test and receiver operating characteristic (ROC) curve analysis. The influence of clinicopathological factors including primary tumor SUVmax and nodal SUVmax on freedom from local failure (LFF), freedom from nodal failure (NFF), freedom from distant failure (DFF), overall survival (OS) and progression-free survival (PFS) were evaluated using univariate and multivariate analysis. Results: Forty patients received trimodality therapy and 62 received definitive chemoradiotherapy (dCRT). Patients receiving trimodality therapy had better outcomes than patients receiving dCRT (2-year OS, 71% v 34%, P Z .001; 2-year PFS, 45% v 17%, P Z .0001; 2-year LFF, 89% v 39%, P Z .0001; 2-year NFF, 78% v 50%, P Z .004; 2-year DFF, 70% v 50%, P Z .054). Nodal SUVmax <7 predicted for improved outcomes for dCRT (2-year DFF, 92% v 17%, P Z .0001; 2-year RFF, 81% v 14%, P Z .001; 2-year OS, 50% v 21%, P Z .003; 2-year PFS, 36% v 3%, P Z .001; No significant difference in LFF), but not trimodality therapy. Primary tumor SUVmax <18.67 only predicted for better 2-year DFF (59% v 37%, P Z .005) for dCRT, but not trimodality therapy. Compared to patients receiving trimodality, patients receiving dCRT with nodal SUVmax <7 were not different on OS (P Z .22), PFS (P Z .17), DFF (P Z .19) and NFF (P Z .60) despite having more advanced disease at baseline, but did worse on LFF (P Z .002); Patients receiving dCRT with nodal SUVmax >7 did significantly worse in OS (P Z .0001), PFS (P Z .0001), DFF (P Z .0001), NFF (P Z .0001) and LFF (P Z .0001) comparing to patients receiving trimodality. On multivariate analysis of patients receiving dCRT, nodal SUVmax <7 is the strongest independent prognostic variable (OS hazard ratio [HR], 3.08 P Z .002; PFS HR, 2.17 P Z .018; DFF HR, 8.33 P Z .002; NFF HR, 3.55 P Z .025). Conclusion: Pretreatment nodal SUVmax was a strong prognostic indicator on nodal failure, distant failure, progression free survival, and overall survival for patients receiving definitive chemoradiotherapy. Planned esophagectomy only improved local control but not nodal control, distant failure and survivals in patients whose pretreatment nodal SUVmax <7. Author Disclosure: W. Yap: None. T. Hung: None. C. Tseng: None. Y. Chang: None.