Study of Respiratory Gated Proton Beam Radiotherapy for Inoperable Pancreas Carcinoma

Inclusion Criteria: * Pathologically confirmed adenocarcinoma of the pancreas or a serum CA19-9 level higher than normal limits and an pancreas cancer-compatible radiological features in one or more in CT/MRI/PET scans * Unresectable disease base on institutional standard criteria of unresectability or recurrent disease following radical surgery. There is no evidence of metastatic disease in the major viscera and no peritoneal seeding * Patients with biliary or gastroduodenal obstruction must have drainage prior to starting chemoradiation * All malignant disease must be encompassable within a single irradiation field (15x15cm maximum) * All patients must have radiographically assessable disease * No previous irradiation to the planned field * Age of ≥ 18 years * Performance status of 0 to 2 on the Eastern Cooperative Oncology Group (ECOG) score * Required Entry Labortory Parameters: * WBC count ≥ 2,000/mm3 * hemoglobin level ≥ 7.5 g/dL * platelet count ≥ 100,000/mm3 * total bilirubin ≤ 2.0 mg/dL (Patients with elevated bilirubin due to obstruction should be stented and their bilirubin should be decreased ≤ 2.0 mg/dL prior to study entry) * creatinine ≤ 3.0 mg/dL * Oral intake (including J-tube feeding) of ≥ 1,500 calories/day should be maintained. Exclusion Criteria: * There is evidence of metastasis in the major viscera or peritoneal seeding. * Age of \< 18 years * Previous history of RT adjacent to planned field * Poor performance status of 3 to 4 on the Eastern Cooperative Oncology Group (ECOG) score * Pregnant or breast feeding status * Previous history uncontrolled other malignancies within 2 years