A free-breathing CT scan with 4-D respiratory correlation was also obtained to characterize target motion during quiet respiration. If target motion was >5 mm, respiratory gating using the Varian Respiratory Management System™ (Stanford), Cyberknife™ respiratory tracking (Stanford), or the Elekta Active Breathing Coordinator System™ (Hopkins) was utilized during treatment delivery. When available (12 of 18 patients), FDG-PET/CT

scans were fused with www.selleckchem.com/products/Belinostat.html simulation scans. SBRT treatment plans were developed using Eclipse™ (Varian, Palo Alto, CA), Multi-Plan™ (Accuray, Sunnyvale, CA), or Pinnacle™ (Philips, Amsterdam, Netherlands). The gross tumor volume (GTV) was contoured Inhibitors,research,lifescience,medical by a radiation oncologist using the simulation scan. An internal target Inhibitors,research,lifescience,medical volume (ITV) was then defined after review of diagnostic imaging, respiratory-correlated

4D-CT, pancreas-protocol CT, and FDG-PET/CT scans. Final planning target volume (PTV) was obtained by an additional 1-3 mm uniform margin expansion of the ITV. The dose was prescribed to the isodose line that completely surrounded the PTV and 6-12 co-planar fields were used to generate the plan Inhibitors,research,lifescience,medical for non-Cyberknife™ treatments. Dose constraints for organs at risk were employed as follows: duodenum—V15Gy<9 cc, V20Gy<3 cc, V33Gy<1 cc; liver—D50%<12 Gy; stomach—D50%<12 Gy, V33Gy<1 cc; spinal cord—V8Gy<1 cc. Institutional standards for patient-specific dosimetric quality assurance were applied. SBRT delivery For non-Cyberknife™-based treatment (N=11), initial patient position was based on cone-beam CT with alignment to spine. Volumetric kV-imaging was then used to align biliary Inhibitors,research,lifescience,medical stent

and/or fiducials to the digitally-reconstructed radiograph. All fiducials were placed specifically for SBRT image guidance using an endoscopic approach (N=11 patients); complications of fiducial placement were observed in only one patient who experienced Inhibitors,research,lifescience,medical laryngospasm and had to return for repeat endoscopy the following day. Common bile duct stents AV-951 were placed endoscopically for relief of symptomatic biliary obstruction and not for purposes of SBRT image guidance, but if a stent was present, then fiducial placement was deemed unnecessary (N=4 patients). If a stent or fiducials were not present, patients were aligned to spine only (N=3). In patients who had previously undergone intra-tumoral fiducial placement, orthogonal kV/MV or kV/kV projection imaging was used to verify fiducial location before first treatment beam delivery and, if indicated, a secondary shift was performed. Active monitoring of treatment delivery accuracy was accomplished using kV and MV projection imaging. For CyberKnife™-based treatment (N=7; fiducials required), initial orthogonal kV/MV or kV/kV projection images were obtained to confirm fiducial location.