Trilogy Stereotactic Body Radiotherapy for Pancreatic Cancer

This study will assess the efficacy of treating locally advanced pancreatic cancer using Stereotactic Body Radiotherapy (using Trilogy) and Gemcitabine

In this study, we propose to combine stereotactic body radiotherapy (SBRT) with standard gemcitabine chemotherapy. We hypothesize that earlier administration of systemic chemotherapy may prolong the interval to distant progression and improve overall survival in these patients. In this study, we will treat pancreatic cancer patients with locally advanced disease with 3 weeks of gemcitabine, followed by Trilogy(TM) SBRT and additional gemcitabine. 30 patients will be accrued to this study at Stanford University Medical Center, the only site participating in this research study. Treatment on this protocol requires placement of 3-5 gold (99.9% pure) fiducials for targeting purposes. Four to 7 days after placement of the fiducials, patients will then undergo a 4D pancreatic protocol CT scan through the upper abdomen. In addition, an FDG PET scan is required for treatment planning purposes. This imaging set will be processed for radiosurgery, using a modified linac based radiation treatment planning system (EclipseTM). An SBRT treatment plan will be developed based on tumor geometry and location. All patients will receive a single fraction of 25 Gy prescribed to the isodose line that completely surrounds the gross pancreatic tumor volume (GTV) as defined by the contrast CT. Following SBRT, patients will be monitored clinically and radiographically.

Patients will have a 4D pancreatic protocol CT and a FDG PET scan scan, both for planning purposes. An SBRT treatment plan will be developed based on tumor geometry and location. All patients will receive a single fraction of 25 Gy dose of Stereotactic Body Radiotherapy on Trilogy Linear Accelerator, followed by weekly Gemcitabine.

Patients will have this imaging procedure along with a CT scan to map the tumor and facilitate treatment planning.

The proportion of patients with local control where local control is defined as no recurrence or disease progression in the primary disease site. Disease progression was defined using either the RECIST or Pet criteria. Using the RECIST criteria disease progression is defined as a more than 25% tumor increase by volume and/ or presence of a new lesion. Using the Pet criteria disease progression is defined as an increase in PET activity as compared to the scan used in the planning of the treatment; any subsequent increase in SUVmax was defined as local progression.

The survival time for each patient is measured as the number of months from randomization until the time of death from any cause. The median survival time is computed using Kaplan Meier curves.

Inclusion Criteria:- Pancreatic tumors not to exceed 10 cm in greatest axial dimension Histologically confirmed malignancies of the pancreas Unresectable by CT criteria or exploratory laparotomy or laparoscopy Patients with metastatic disease may be treated if they are symptomatic from the primary tumor Performance status of 0, 1, or 2 No chemotherapy two weeks prior or two weeks following radiosurgery Exclusion Criteria: patients who have had prior radiotherapy to upper abdomen patients receiving any prior pancreatic cancer therapy children, pregnant, and breastfeeding women, and lab personnel are excluded uncontrolled intercurrent illnesses any concurrent malignancy