SBRT for Close or Positive Margins After Resection of Pancreatic Adenocarcinoma A Prospective Evaluation in Select Patients With Resected Pancreas Cancer
Radiation simulation will be done in Shadyside Radiation Oncology department
Contrast-enhanced CT based simulation will be obtained prior to any adjuvant treatment (2-4
weeks post-op depending on healing). The target volume will be identified based on fiducial
marker placement at time of surgery as well as a detailed discussion and image review with
the operating surgeon. This are will be contoured on axial CT images obtained at 1.25 mm
slice thickness. These volumes will then be reconstructed into a 3-dimensional image set for
SBRT planning. Subjects will be simulated in the treatment position (supine with arms
raised) on the CT scanner table the appropriate immobilization. Optiray® contrast will be
administered intravenously at a flow rate of 2.5 mL/s. A helical CT scan of the abdomen will
be acquired with intravenous contrast starting 30 seconds prior to CT acquisition.
A 4D CT data acquisition for the same axial extent will be obtained. The images will then be
electronically transferred from the CT workstation via DICOM3 to the appropriate treatment
planning workstation in the department of radiation oncology. Based on axial CT images,
fiducial marker placement, review of the pathology report, and a detailed discussion with
the operating surgeon, contours will be drawn of the clinical target volume (CTV), which is
defined as the area at risk for microscopic disease. The planning target volume (PTV) will
be equivalent to the CTV unless motion is detected on the 4D motion study. If there is
motion, the amount of motion in the superior-inferior, lateral, and anterior-posterior
directions will be the margin given. Surrounding normal and critical structures will also be
contoured by the treating radiation oncologist including the kidneys, liver, small bowel,
spinal cord, and stomach if necessary.
Stereotactic Body Radiotherapy Planning An SBRT plan will be created by a medical physicist
based on the PTV contoured on the CT scan. The plan will be to deliver fractionated SBRT to
the isodose line best encompassing the PTV.
Careful evaluation of each plan will be conducted by the radiosurgical team to ensure that
normal tissues and critical structures tolerances are maintained.
The maximum dose (in Gy) within the treatment volume (MD), prescriptions dose (PD), and the
ratio of MD/PD (as a measure of heterogeneity within the target volume), prescription
isodose volume (PIV in mm3), tumor volume (TV in mm3), and the ratio of PIV/TV (as a measure
of dose conformity of the treatment relative to the target) will be recorded.
Evaluation during treatment The subjects will be carefully followed while on active
treatment and post-treatment for 24 months, or until death.
Treatment following SBRT All patients will have been seen in a multi-disciplinary pancreatic
cancer clinic. As such, they will be set up with a medical oncologist. Following completion
of SBRT as described in this protocol, the patient's medical oncologist may, at his/her
discretion, administer systemic therapy according to the current standard of care or the
Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
To determine the rate of local progression-free survival (LPFS) with two years of follow-up in subjects with margin positive or close margins following resection of pancreatic adenocarcinoma treated with SBRT.
In this study, LPFS is defined as the time from enrollment to first documentation of progressive disease (PD) in the target lesion. Death or development of distant disease is not regarded as an event. For patients that undergo surgical resection, local progression will be defined as disease recurrence detected on follow-up imaging (CT or FDG-PET/CT) that is located within the SBRT target volume.
Dwight E Heron, MD
United States: Institutional Review Board
|UPMC Shadyside Radiation Oncology||Pittsburgh, Pennsylvania 15232|