Previously, fiducials had primarily been implanted into the pancreas under computed tomography (CT) or ultrasound guidance, however there is now growing evidence for using endoscopic ultrasound for fiducial placement.
Endoscopic ultrasound avoids the percutaneous routes used with CT- or ultrasound-guided placement, however the exact adverse event profile has yet to be fully elucidated. Both CT- or ultrasound- guided fiducial implantation carries the risk of “tumor seeding,” where small pieces of tumor may be spread within the abdominal cavity during the procedure.3
Common side effects reported after EUS-guided fiducial implantation include pancreatitis, abdominal pain, and fiducial migration.1
Patients with prior pancreatic or abdominal surgeries may not be the ideal candidates for endoscopic ultrasound-guided fiducial implantation as their anatomy can make access to the pancreas technically difficult.
The efficacy and safety data of SBRT in patients with pancreatic cancer is variable based on how advanced the pancreatic cancer is, whether or not adjuvant chemotherapy was used, and the dose of radiation administered.
There is more experience with SBRT in pancreatic cancers in patients with locally advanced disease with “borderline resectable” or local recurrence after standard chemotherapy and most of the data supports a modest improvement in local control of the tumor and overall survival when using SBRT compared to standard radiation therapy.4
Toxicities associated with SBRT include fatigue, nausea, vomiting, and diarrhea. These toxicities appear to be less common when compared to those experienced with traditional radiation therapy for pancreatic cancer, however this is dependent on the dose and number of radiation treatments.
In addition to less frequent overall side effects, the amount of grade 3 or 4 toxicities also appear to be less common with SBRT.4
Caution should be used when interpreting this data, as many of the studies available to date are limited by a relative paucity of heterogeneous patients as SBRT is a developing therapy. Additional studies are needed to further identify the best patients in which to use SBRT.
- Sanders MK, Moser AJ, Khalid A, et al. EUS-guided fiducial placement for stereotactic body radiotherapy in locally advanced and recurrent pancreatic cancer. Gastrointest Endosc. 2010;71(7):1178-1184.
- Khashab MA, Kim KJ, Tryggestad EJ, et al. Comparative analysis of traditional and coiled fiducials implanted during EUS for pancreatic cancer patients receiving stereotactic body radiation therapy. Gastrointest Endosc. 2012;76(5):962-971.
- Lewis JJ, Kowalski TE. Endoscopic ultrasound and fine needle aspiration in pancreatic cancer. Cancer J. 2012;18(6):523-529.
- Trakul N, Koong AC, Chang DT. Stereotactic body radiotherapy in the treatment of pancreatic cancer. Semin Radiat Oncol. 2014;24(2):140-147.