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Comparison of Conditional Survival in Patients With Gastrointestinal Malignancies Treated With Radiation: A Population-Based Analysis
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Volume 90 Number 1S Supplement 2014 recurrence rates for patients treated with IMRT using dose painting or sequential boost techniques. Author Disclosure: C.R. Spencer: None. M. Cardenas: None. T.A. DeWees: None. R. Jain: None. P. Grigsby: None. B. Tan: None. M. Silviera: None. S. Hunt: None. R.J. Myerson: None. P.J. Parikh: None. J.R. Olsen: G. Consultant; DFine, Inc. I. Travel Expenses; DFine, Inc, RSNA Resident & Fellow Committee.
2473 Comparison of Conditional Survival in Patients With Gastrointestinal Malignancies Treated With Radiation: A Population-Based Analysis A.J. Patel, J. Daniels, J. Vincent, and T. Eng; University of Texas Health Science Center San Antonio, San Antonio, TX Purpose/Objective(s): Survival probability is not a static measure after diagnosis and treatment. At the time of diagnosis, patients are given survival outcomes which are determined from the time of diagnosis. Conditional survival (CS) statistics try to accurately determine the probability of survival after a designated period of time by taking into account continuously changing hazard rates over time. Patients who survive the first couple of years after treatment are presumed to have passed a window of disease recurrence or spread. CS modeling may help direct treatment selection and post-treatment surveillance. Gastrointestinal malignancies make up a substantial portion of newly diagnosed cancer cases and were evaluated in this project. Materials/Methods: A total of 69,078 cases of gastrointestinal malignancies (groups Z esophagus, stomach, pancreas, rectum, anal and hepatobiliary) diagnosed from 1998-2010 were identified from the Surveillance, Epidemiology, and End Results (SEER 18) program who were treated with radiation. Cases which were included had the designation of “local” or “regional” disease and were recorded as having received beam radiation and/or brachytherapy. Five year CS models were determined for each anatomic group based on the SEER data dictionary for patients who had already survived up to 5 years from diagnosis. Observed survival (OS) data were also obtained. Results: The group with the greatest change in CS was pancreas which showed an improvement in 5-yr CS of 39.2%. The groups with the least change in CS were rectal and anal primaries which showed an improvement in 5-yr CS of 1.4% and 5.1% respectively. The greatest magnitude of difference between OS and CS at 5 years were for the groups pancreas, esophagus and hepatobiliary at 78%, 70% and73% respectively. The least magnitude of difference between OS and CS at 5 years were for the rectum and anal groups at 31% and 32% respectively. Conclusions: All groups of gastrointestinal malignancies were noted to have an improvement in CS with the greatest magnitude in pancreatic and hepatobiliary primaries but closely followed by esophageal and stomach primaries. Rectal and anal malignancies were noted to have the least improvement in CS most likely related to the effectiveness of treatment. This data has important implications regarding post-therapy surveillance of gastrointestinal malignancies as CS statistics aim to accurately determine the probability of survival by accounting for continuously changing hazard rates over time. Author Disclosure: A.J. Patel: None. J. Daniels: None. J. Vincent: None. T. Eng: None.
2474 Robotic Stereotactic Body Radiation Therapy in Patients With Recurrent or Metastatic Abdominopelvic Tumors: A Single-Institute Experience D. Sezen, M. Gurkaynak, M. Gultekin, M. Cengiz, F. Yildiz, F. Zorlu, F. Akyol, G. Yazici, P. Hurmuz, and G. Ozyigit; Department of Radiation Oncology, Hacettepe University, Faculty of Medicine, Ankara, Turkey Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) has been used successfully to treat patients with extracranial malignancies. The aim of this study was to evaluate efficacy and toxicity of robotic Cyberknife (Accuray, Sunnyvale, CA)-based SBRT in patients with recurrent or metastatic abdominopelvic tumors.
Materials/Methods: A total of 69 patients treated between May 2008 and January 2011 were retrospectively evaluated. Thirty-eight (55%) patients were reirradiated for local recurrence and 31 (45%) patients were treated for the first time. The median age was 59 years (range, 24-86 years). There were 31 (45%) male and 38 (55%) female patients. The median total dose was 30 Gy (range, 15-60 Gy) delivered with a median 3 fractions (range, 2-5 fraction). The tumor response to treatment was assessed by computed tomography (CT), magnetic resonance imaging (MRI) or positron emission tomography (PET). Results: At 12 months (range, 2-44 months) median follow-up, local control was 65% median overall survival (OS) was 23 months. The longest survival (median, 36 months) was observed in the patients with adrenal gland metastasis and the shortest (median, 11.5 months) with gynecologic tumors. A larger gross tumor volume (116 cc) was significantly correlated with worse OS (median, 11 months). Grade 3-4 acute and late toxicity were seen in 7% and 14.5% of patients, respectively. Late toxicity was significantly higher in pelvic tumors than in abdominal tumors (26% vs 5%, p Z 0.035). Conclusions: SBRT seems to be feasible and resulted in good treatment outcomes in patients with recurrent or metastatic abdominopelvic tumors. Author Disclosure: D. Sezen: None. M. Gurkaynak: None. M. Gultekin: None. M. Cengiz: None. F. Yildiz: None. F. Zorlu: None. F. Akyol: None. G. Yazici: None. P. Hurmuz: None. G. Ozyigit: None.
2475 Intensity Modulated Radiation Therapy Utilization in the Treatment of Gastrointestinal Malignancies Between 2000 and 2009 in the SEER-Medicare Population M. Palta,1 B.G. Czito,1 C.G. Willett,1 and M.A. Dinan2; 1Duke University Medical Center, Durham, NC, 2Duke Clinical Research Institute, Durham, NC Purpose/Objective(s): Intensity modulated radiation therapy (IMRT) is a novel approach to radiation treatment planning and delivery. Numerous dosimetric studies in gastrointestinal (GI) malignancies have shown that the integration of IMRT is feasible and, when compared with conventional radiation therapy approaches, results in improved normal tissue sparing. Retrospective comparisons have demonstrated improvements in acute and late toxicity rates with selected studies demonstrating superior treatment outcomes with IMRT. Randomized trials comparing conventional radiation therapy with IMRT are sparse. Despite limited data evaluating the incremental value of IMRT over conventional radiation therapy, increased utilization of IMRT has been observed in the treatment of breast, prostate and head and neck malignancies. In this study we examined IMRT utilization in the treatment of GI malignancies using Surveillance, Epidemiology, and End Results Program (SEER)-Medicare linked data. Materials/Methods: This study is a retrospective claims-based analysis of SEER-Medicare patients diagnosed with GI malignancy between 2000 and 2009. Radiation therapy, and specifically IMRT use, was assessed over time. Unadjusted and adjusted regression analysis was performed to assess factors associated with receipt of IMRT. Results: A total of 135,807 patients with GI malignancies were identified of which 14,514 received external beam RT (11%). Among patients undergoing external beam RT, IMRT utilization increased with time from <0.1% of cases in 2000-2001, 4.7% in 2002-2003, 11.4% in 2004-2005, 23.1% in 2006-2007 to 37.3% of cases in 2008-2009 (p<0.0001). Of patients receiving radiation therapy, thirty percent or more of GI patients from each sub-site (anal, colorectal, esophagus, liver/hepatobiliary, pancreas, and stomach) were treated with IMRT by 2009, with more than half of patients with anal and pancreatic malignancies undergoing IMRT by 2009. On adjusted regression analysis, age, race, comorbidity, socioeconomic status and marital status were not associated with use of IMRT. Factors associated with receipt of IMRT in adjusted analyses including living within the Northeast (OR 1.53, 1.01-2.33), South (OR 2.68, 1.564.63) or West (OR 2.53, 1.48-4.33) compared with the Midwest, later year of diagnosis, and non-colorectal GI cancer sub-site. Conclusions: Analysis of SEER-Medicare data from 2000-2009 indicates increasing utilization of IMRT in the management of patients with GI malignancies.
Volume 90 Number 1S Supplement 2014 recurrence rates for patients treated with IMRT using dose painting or sequential boost techniques. Author Disclosure: C.R. Spencer: None. M. Cardenas: None. T.A. DeWees: None. R. Jain: None. P. Grigsby: None. B. Tan: None. M. Silviera: None. S. Hunt: None. R.J. Myerson: None. P.J. Parikh: None. J.R. Olsen: G. Consultant; DFine, Inc. I. Travel Expenses; DFine, Inc, RSNA Resident & Fellow Committee.
2473 Comparison of Conditional Survival in Patients With Gastrointestinal Malignancies Treated With Radiation: A Population-Based Analysis A.J. Patel, J. Daniels, J. Vincent, and T. Eng; University of Texas Health Science Center San Antonio, San Antonio, TX Purpose/Objective(s): Survival probability is not a static measure after diagnosis and treatment. At the time of diagnosis, patients are given survival outcomes which are determined from the time of diagnosis. Conditional survival (CS) statistics try to accurately determine the probability of survival after a designated period of time by taking into account continuously changing hazard rates over time. Patients who survive the first couple of years after treatment are presumed to have passed a window of disease recurrence or spread. CS modeling may help direct treatment selection and post-treatment surveillance. Gastrointestinal malignancies make up a substantial portion of newly diagnosed cancer cases and were evaluated in this project. Materials/Methods: A total of 69,078 cases of gastrointestinal malignancies (groups Z esophagus, stomach, pancreas, rectum, anal and hepatobiliary) diagnosed from 1998-2010 were identified from the Surveillance, Epidemiology, and End Results (SEER 18) program who were treated with radiation. Cases which were included had the designation of “local” or “regional” disease and were recorded as having received beam radiation and/or brachytherapy. Five year CS models were determined for each anatomic group based on the SEER data dictionary for patients who had already survived up to 5 years from diagnosis. Observed survival (OS) data were also obtained. Results: The group with the greatest change in CS was pancreas which showed an improvement in 5-yr CS of 39.2%. The groups with the least change in CS were rectal and anal primaries which showed an improvement in 5-yr CS of 1.4% and 5.1% respectively. The greatest magnitude of difference between OS and CS at 5 years were for the groups pancreas, esophagus and hepatobiliary at 78%, 70% and73% respectively. The least magnitude of difference between OS and CS at 5 years were for the rectum and anal groups at 31% and 32% respectively. Conclusions: All groups of gastrointestinal malignancies were noted to have an improvement in CS with the greatest magnitude in pancreatic and hepatobiliary primaries but closely followed by esophageal and stomach primaries. Rectal and anal malignancies were noted to have the least improvement in CS most likely related to the effectiveness of treatment. This data has important implications regarding post-therapy surveillance of gastrointestinal malignancies as CS statistics aim to accurately determine the probability of survival by accounting for continuously changing hazard rates over time. Author Disclosure: A.J. Patel: None. J. Daniels: None. J. Vincent: None. T. Eng: None.
2474 Robotic Stereotactic Body Radiation Therapy in Patients With Recurrent or Metastatic Abdominopelvic Tumors: A Single-Institute Experience D. Sezen, M. Gurkaynak, M. Gultekin, M. Cengiz, F. Yildiz, F. Zorlu, F. Akyol, G. Yazici, P. Hurmuz, and G. Ozyigit; Department of Radiation Oncology, Hacettepe University, Faculty of Medicine, Ankara, Turkey Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) has been used successfully to treat patients with extracranial malignancies. The aim of this study was to evaluate efficacy and toxicity of robotic Cyberknife (Accuray, Sunnyvale, CA)-based SBRT in patients with recurrent or metastatic abdominopelvic tumors.
Materials/Methods: A total of 69 patients treated between May 2008 and January 2011 were retrospectively evaluated. Thirty-eight (55%) patients were reirradiated for local recurrence and 31 (45%) patients were treated for the first time. The median age was 59 years (range, 24-86 years). There were 31 (45%) male and 38 (55%) female patients. The median total dose was 30 Gy (range, 15-60 Gy) delivered with a median 3 fractions (range, 2-5 fraction). The tumor response to treatment was assessed by computed tomography (CT), magnetic resonance imaging (MRI) or positron emission tomography (PET). Results: At 12 months (range, 2-44 months) median follow-up, local control was 65% median overall survival (OS) was 23 months. The longest survival (median, 36 months) was observed in the patients with adrenal gland metastasis and the shortest (median, 11.5 months) with gynecologic tumors. A larger gross tumor volume (116 cc) was significantly correlated with worse OS (median, 11 months). Grade 3-4 acute and late toxicity were seen in 7% and 14.5% of patients, respectively. Late toxicity was significantly higher in pelvic tumors than in abdominal tumors (26% vs 5%, p Z 0.035). Conclusions: SBRT seems to be feasible and resulted in good treatment outcomes in patients with recurrent or metastatic abdominopelvic tumors. Author Disclosure: D. Sezen: None. M. Gurkaynak: None. M. Gultekin: None. M. Cengiz: None. F. Yildiz: None. F. Zorlu: None. F. Akyol: None. G. Yazici: None. P. Hurmuz: None. G. Ozyigit: None.
2475 Intensity Modulated Radiation Therapy Utilization in the Treatment of Gastrointestinal Malignancies Between 2000 and 2009 in the SEER-Medicare Population M. Palta,1 B.G. Czito,1 C.G. Willett,1 and M.A. Dinan2; 1Duke University Medical Center, Durham, NC, 2Duke Clinical Research Institute, Durham, NC Purpose/Objective(s): Intensity modulated radiation therapy (IMRT) is a novel approach to radiation treatment planning and delivery. Numerous dosimetric studies in gastrointestinal (GI) malignancies have shown that the integration of IMRT is feasible and, when compared with conventional radiation therapy approaches, results in improved normal tissue sparing. Retrospective comparisons have demonstrated improvements in acute and late toxicity rates with selected studies demonstrating superior treatment outcomes with IMRT. Randomized trials comparing conventional radiation therapy with IMRT are sparse. Despite limited data evaluating the incremental value of IMRT over conventional radiation therapy, increased utilization of IMRT has been observed in the treatment of breast, prostate and head and neck malignancies. In this study we examined IMRT utilization in the treatment of GI malignancies using Surveillance, Epidemiology, and End Results Program (SEER)-Medicare linked data. Materials/Methods: This study is a retrospective claims-based analysis of SEER-Medicare patients diagnosed with GI malignancy between 2000 and 2009. Radiation therapy, and specifically IMRT use, was assessed over time. Unadjusted and adjusted regression analysis was performed to assess factors associated with receipt of IMRT. Results: A total of 135,807 patients with GI malignancies were identified of which 14,514 received external beam RT (11%). Among patients undergoing external beam RT, IMRT utilization increased with time from <0.1% of cases in 2000-2001, 4.7% in 2002-2003, 11.4% in 2004-2005, 23.1% in 2006-2007 to 37.3% of cases in 2008-2009 (p<0.0001). Of patients receiving radiation therapy, thirty percent or more of GI patients from each sub-site (anal, colorectal, esophagus, liver/hepatobiliary, pancreas, and stomach) were treated with IMRT by 2009, with more than half of patients with anal and pancreatic malignancies undergoing IMRT by 2009. On adjusted regression analysis, age, race, comorbidity, socioeconomic status and marital status were not associated with use of IMRT. Factors associated with receipt of IMRT in adjusted analyses including living within the Northeast (OR 1.53, 1.01-2.33), South (OR 2.68, 1.564.63) or West (OR 2.53, 1.48-4.33) compared with the Midwest, later year of diagnosis, and non-colorectal GI cancer sub-site. Conclusions: Analysis of SEER-Medicare data from 2000-2009 indicates increasing utilization of IMRT in the management of patients with GI malignancies.