Computed Tomography in Diagnosing Patients With Pancreatic or Hepatobiliary Cancer

Inclusion Criteria: * PANCREATIC CANCER: Histologically confirmed adenocarcinoma of the pancreas * PANCREATIC CANCER: Non-distant metastatic pancreatic cancer that is either * Unresectable locally advanced disease, defined as primary tumor that involves \> 180 degrees of the superior mesenteric artery, celiac axis or any of its branches on CT or MRI, primary tumor that occludes the superior mesenteric vein or portal vein, aorta or inferior vena cava invasion, or superior mesenteric vein invasion below the transverse mesocolon * Borderline resectable disease, defined as primary tumor that involves =\< 180 degrees of the superior mesenteric artery, celiac axis or any of its branches on CT or MRI, primary tumor that involves the superior mesenteric vein causing vein deformity or segmental venous occlusion with a patent vessel above and below suitable for reconstruction, or primary tumor that abuts or encases (\>= 50% of the vessel circumference) a short segment of the common hepatic artery (typically at the gastroduodenal artery origin) * PANCREATIC CANCER: Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1 * PANCREATIC CANCER: Women of childbearing potential (those who have not undergone a hysterectomy or who have not been postmenopausal for at least 24 consecutive months) must agree to practice adequate contraception and to refrain from breast feeding * PANCREATIC CANCER: Patient who has been recommended chemotherapy treatment for pancreatic cancer * PANCREATIC CANCER: Signed study-specific consent form * HEPATOBILIARY CANCER: Diagnosis of * Hepatocellular carcinoma: This may be diagnosed in the following ways: * Pathologically (histologically or cytologically) proven diagnosis of hepatocellular carcinoma (HCC) * At least one solid liver lesion with arterial enhancement and washout on a delayed phase of a multi-phasic CT or MRI in the setting of cirrhosis or chronic hepatitis B or C without cirrhosis * Intrahepatic cholangiocarcinoma: Pathologically (histologically or cytologically) proven diagnosis of intrahepatic cholangiocarcinoma * HEPATOBILIARY CANCER: Patients may have single or multinodular tumors * HEPATOBILIARY CANCER: ECOG PS 0-1 * HEPATOBILIARY CANCER: Women of childbearing potential (those who have not undergone a hysterectomy or who have not been postmenopausal for at least 24 consecutive months) must agree to practice adequate contraception * HEPATOBILIARY CANCER: Prior history of surgical resection, chemotherapy, transarterial chemoembolization (TACE), and/or radiofrequency ablation are allowed * HEPATOBILIARY CANCER: Patients may be enrolled if: * The patient is dispositioned to receive definitive radiotherapy * The patient has received definitive radiotherapy within the past two years and has liver protocol CT or MRI scans before radiotherapy and at first restaging after radiotherapy * HEPATOBILIARY CANCER: Signed study-specific consent form Exclusion Criteria: * Presence of distant metastasis * Patients whose tumors are defined as resectable * Unstable angina or New York Heart Association grade II or greater congestive heart failure * Evidence of fever or acute infection (chronic infection such as hepatitis virus is acceptable) * Coexisting medical condition that would preclude chemotherapy, radiotherapy, or iodine-based contrast enhanced CT scan * Pregnant women with a positive pregnancy test * Inability to comply with study and/or follow-up procedures * Patients with an active second malignancy with the exception of non-melanoma skin cancer