Sbrt Of The Pancreas With Depleted Iodine Seeds For Image Guidance: Fiducials That Are Easily Seen And Green

Conventional therapies have not been effective in the treatment of pancreatic cancer. Stereotactic body radiation therapy (SBRT) is a novel technique that is predicated on technological advances in image guidance which aspire to deliver ablative doses of irradiation. SBRT mandates a high degree of confidence in tumor localization. We recently reported the application of depleted radioactive sources (i.e., I-125 seeds that were no longer suitable for prostate brachytherapy) as fiducial markers for external irradiation of prostate cancer. Those seeds were chosen since, unlike gold seeds, they do not create artifacts on CT images are widely available in Radiation Oncology Departments. We describe, herein, the feasibility of incorporating such depleted sources in SBRT programs for pancreatic cancer. An 80-year-old woman with resectable pancreatic cancer declined to undergo resection (Whipple Procedure). Compassionate use was granted to treat with SBRT. Depleted I-125 seeds were endoscopically implanted to localize the target. Treatment delivery consisted of 3 fractions of 12 Gy after the patient was trained to use an Automatic Breathing Coordinator. The seeds were successfully implanted in the patient. The fiducials were easily visualized and target was clearly identified. No seed migration occurred. No significant artifact was encountered. No acute complications occurred. SBRT is a biologically appealing alternative for the management of pancreatic cancer. The use of depleted iodine seeds as a component of SBRT programs is not only feasible but also attractive since most radiotherapy departments have access to this resource and the seeds are easily identifiable without inducing artifact that impairs interpretation on conventional imaging modalities. We have embarked on an IRB-approved protocol to advance this approach.