Commissioning of HDR Brachytherapy Combined with an Applicator-Guided SBRT Boost for Advanced Cervical Cancer

There is emerging evidence that dose escalation to high-risk clinical target volume leads to improved clinical outcome in cervical cancer. At time of brachytherapy, options for patients with large residual disease include a parametrial boost which lacks precision, or the addition of interstitial needles which requires a specialized brachytherapy program. The option of combining HDR brachytherapy (HDRB) with stereotactic body radiation therapy (SBRT) boost is being explored at our institution as a viable alternative for interstitial brachytherapy. The aim of this study is to describe an EBT3 GAFCHROMIC™ film dosimetry system to be used in commissioning of this combined boost, and to evaluate effect of positional inaccuracies on the overall dosimetric outcome.