Is Extended Volume of External Beam Irradiation Beneficial in Post-esophagectomy High Risk Patients Receiving Combined Chemoradiation Therapy?

OBJECTIVE: To assess the value of extended volume irradiation with anastomotic coverage in high risk resected esophageal cancer patients. METHOD: A retrospective study was undertaken at LRCC from 1989-1999 for high risk resected esophageal cancer patients. Adjuvant treatments consisted of 4 cycles of chemotherapy (epirubicin/fluorouracil/cisplatin or cisplatin/fluorouracil), and local regional irradiation with or without coverage of the anastomotic site. Radiation dose ranged from 45-60Gy at 1.8-2.0 Gy/fraction given with initial anterior-posterior/posterior-anterior arrangement with either extended (with anastomotic coverage) or small (without anastomotic coverage) field followed by oblique fields for boost. RESULT: One hundred eighty-eight charts were reviewed. Seventy-two patients were eligible for post-resection chemoradiation therapy. Three patients had disease progression prior to therapy, and 69 patients were analyzed. There were 81% T3N1 and 13% T2N1. Thirty-four patients had margin involvements (radial 53%; proximal/distal 32%), 65% were adenocarcinoma and 33% were squamous carcinoma. Median followup was 23.6 months (3.4 - 78.4 months). Two year survival was 50%; 5yr 24%. Relapse rate was 62.3% and median time to relapse was 20 months. Recurrence locally to anastomosis or adjacent to anastomosis was 9/43(20.9%) with small field and 2/26(7.7%) with extended field. Of 31 patients with relapse outside anastomosis, 14/20(70%) relapsed locoregional/distal when treated with small field and 3/11(27%) relapsed locoregional/distal when treated with extended field (p=0.02). There was no excess treatment interruption or chronic gastrointestinal toxicity with extended field irradiation. CONCLUSION: There is significant decrease in locoregional/distal relapse with use of extended field in high risk resected esophageal cancer patients

Applications of electrified dust and dust devil electrodynamics to Martian atmospheric electricity

Atmospheric transport and suspension of dust frequently brings electrification, which may be substantial. Electric fields of 10 kVm-1 to 100 kVm-1 have been observed at the surface beneath suspended dust in the terrestrial atmosphere, and some electrification has been observed to persist in dust at levels to 5 km, as well as in volcanic plumes. The interaction between individual particles which causes the electrification is incompletely understood, and multiple processes are thought to be acting. A variation in particle charge with particle size, and the effect of gravitational separation explains to, some extent, the charge structures observed in terrestrial dust storms. More extensive flow-based modelling demonstrates that bulk electric fields in excess of 10 kV m-1 can be obtained rapidly (in less than 10 s) from rotating dust systems (dust devils) and that terrestrial breakdown fields can be obtained. Modelled profiles of electrical conductivity in the Martian atmosphere suggest the possibility of dust electrification, and dust devils have been suggested as a mechanism of charge separation able to maintain current flow between one region of the atmosphere and another, through a global circuit. Fundamental new understanding of Martian atmospheric electricity will result from the ExoMars mission, which carries the DREAMS (Dust characterization, Risk Assessment, and Environment Analyser on the Martian Surface)-MicroARES (Atmospheric Radiation and Electricity Sensor) instrumentation to Mars in 2016 for the first in situ measurements

Is Extended Volume of External Beam Irradiation Beneficial in Post-esophagectomy High Risk Patients Receiving Combined Chemoradiation Therapy?

OBJECTIVE: To assess the value of extended volume irradiation with anastomotic coverage in high risk resected esophageal cancer patients. METHOD: A retrospective study was undertaken at LRCC from 1989-1999 for high risk resected esophageal cancer patients. Adjuvant treatments consisted of 4 cycles of chemotherapy (epirubicin/fluorouracil/cisplatin or cisplatin/fluorouracil), and local regional irradiation with or without coverage of the anastomotic site. Radiation dose ranged from 45-60Gy at 1.8-2.0 Gy/fraction given with initial anterior-posterior/posterior-anterior arrangement with either extended (with anastomotic coverage) or small (without anastomotic coverage) field followed by oblique fields for boost. RESULT: One hundred eighty-eight charts were reviewed. Seventy-two patients were eligible for post-resection chemoradiation therapy. Three patients had disease progression prior to therapy, and 69 patients were analyzed. There were 81% T3N1 and 13% T2N1. Thirty-four patients had margin involvements (radial 53%; proximal/distal 32%), 65% were adenocarcinoma and 33% were squamous carcinoma. Median followup was 23.6 months (3.4 - 78.4 months). Two year survival was 50%; 5yr 24%. Relapse rate was 62.3% and median time to relapse was 20 months. Recurrence locally to anastomosis or adjacent to anastomosis was 9/43(20.9%) with small field and 2/26(7.7%) with extended field. Of 31 patients with relapse outside anastomosis, 14/20(70%) relapsed locoregional/distal when treated with small field and 3/11(27%) relapsed locoregional/distal when treated with extended field (p=0.02). There was no excess treatment interruption or chronic gastrointestinal toxicity with extended field irradiation. CONCLUSION: There is significant decrease in locoregional/distal relapse with use of extended field in high risk resected esophageal cancer patients

Is Extended Volume of External Beam Irradiation Beneficial in Post-esophagectomy High Risk Patients Receiving Combined Chemoradiation Therapy?

OBJECTIVE: To assess the value of extended volume irradiation with anastomotic coverage in high risk resected esophageal cancer patients. METHOD: A retrospective study was undertaken at LRCC from 1989-1999 for high risk resected esophageal cancer patients. Adjuvant treatments consisted of 4 cycles of chemotherapy (epirubicin/fluorouracil/cisplatin or cisplatin/fluorouracil), and local regional irradiation with or without coverage of the anastomotic site. Radiation dose ranged from 45-60Gy at 1.8-2.0 Gy/fraction given with initial anterior-posterior/posterior-anterior arrangement with either extended (with anastomotic coverage) or small (without anastomotic coverage) field followed by oblique fields for boost. RESULT: One hundred eighty-eight charts were reviewed. Seventy-two patients were eligible for post-resection chemoradiation therapy. Three patients had disease progression prior to therapy, and 69 patients were analyzed. There were 81% T3N1 and 13% T2N1. Thirty-four patients had margin involvements (radial 53%; proximal/distal 32%), 65% were adenocarcinoma and 33% were squamous carcinoma. Median followup was 23.6 months (3.4 - 78.4 months). Two year survival was 50%; 5yr 24%. Relapse rate was 62.3% and median time to relapse was 20 months. Recurrence locally to anastomosis or adjacent to anastomosis was 9/43(20.9%) with small field and 2/26(7.7%) with extended field. Of 31 patients with relapse outside anastomosis, 14/20(70%) relapsed locoregional/distal when treated with small field and 3/11(27%) relapsed locoregional/distal when treated with extended field (p=0.02). There was no excess treatment interruption or chronic gastrointestinal toxicity with extended field irradiation. CONCLUSION: There is significant decrease in locoregional/distal relapse with use of extended field in high risk resected esophageal cancer patients