Smartadapt

The daily CBCTs were directly accessible in the commercial treatment management software for DIR using a Demon’s-based contour propagation (6 (link)) and dose calculations (SmartAdapt, Varian Medical Systems, Palo Alto, CA). Figure 1 shows contours on the planning CT and the same contours propagated on the CBCT of a different fraction. Figure 2 shows the planned dose distribution and the recalculated dose on a daily CBCT. The calibrations between the CBCT and planning CT were matched using monthly measurements (QA) of standard materials with known electron density (Catphan®). The delivered dose at each fraction was calculated on the daily CBCT, and the dose was evaluated based on the propagated contours.

Pre-treatment full body PET-CT scans were obtained in our nuclear medicine department in accordance with standard protocol for a majority of patients (51/57) on a Siemens Biograph Classic, Biograph T6 or Biograph 40 (Siemens Medical Solutions, Hoffman Estates, IL). Scans from the remaining six patients were obtained from outside institutions on either a Siemens Biograph Classic or GE ST/STE (GE Medical Systems, GE Healthcare, Chicago, IL). All 3-month post-treatment imaging was performed within our institution. Parotid glands were manually contoured by a Radiation Oncology MD on all pre-treatment CT scans in our treatment planning system (Aria, Varian Medical Systems). The contours were copied to the registered PET scan, and deformable registration (SmartAdapt, Varian Medical Systems) was used to copy the contours to the 3-month CT and PET scans. The deformed contours were visually inspected for accuracy and manually adjusted as needed (2 cases).