Standard radiation therapy (RT) for pancreatic cancer, whether administered before or after surgery, is given because of its proven role in reducing post surgical tumor recurrences. Even in patients thought to have surgically resectable pancreatic cancer on baseline imaging, benefit with the addition of RT has been suggested. However, such treatment typically takes five to six weeks. There is interest in shortening the treatment duration if possible, both for patient convenience and to avoid excessive delays in performing surgery or delivering other supplemental treatment. Stereotactic body radiation therapy (SBRT) is a novel and emerging alternate radiation therapy approach that allows delivery of fewer but higher daily doses of radiation, resulting in completion of therapy in just 1-2 weeks.
A phase I dose escalation study is being performed in conjunction with radiation oncology to explore the maximum tolerable dose of SBRT when combined with standard dose capecitabine chemotherapy in resectable pancreas cancer. However, with this abbreviated treatment, accurate tumor response assessment is critical. While the pathological specimen obtained at the time of surgery provides the ultimate determinant of tumor response, a reliable early surrogate marker of tumor response that can be applied during or after neoadjuvant therapy but prior to surgery, could be invaluable in guiding the surgery. Improved techniques in magnetic resonance imaging (MRI) may allow its development as one such marker. Therefore, the goal of this companion pilot study is to evaluate the use of MRI as a novel marker of pancreatic tumor response to neoadjuvant SBRT and chemotherapy. At this point, there are no published clinical studies evaluating this approach. We propose to assess MRI imaging features including change in tumor volume, dynamic contrast enhancement and ADC values to evaluate response to therapy. We would correlate these changes with the pathologic specimen at the time of surgery.