Abstract
PURPOSE: In cervical cancer brachytherapy, adding interstitial (IS) needles to intracavitary (IC) applicators can enhance dosimetry by improving target coverage while limiting normal tissue dose. However, its use is limited to a subset of practitioners with appropriate technical skill. We designed Tandem Anchored Radially Guiding Interstitial Templates (TARGITs) with a 3D printing workflow to optimize needle placement and facilitate greater ease-of-use of IC/IS technique. This study compared dosimetry and procedure characteristics between tandem-and-ovoid implants (T&O) using TARGIT technique versus non-TARGIT technique.METHODS AND MATERIALS: This single-institution retrospective cohort study included patients undergoing T&O brachytherapy as part of definitive radiation treatment for cervical cancer between February 2017 and January 2021. TARGIT technique was implemented from November 2019 onwards; all prior procedures involved non-TARGIT technique using a No Needle (NN) or Freehand Needle (FN) approach. Target coverage, dose to organs-at-risk, and procedure times were evaluated and compared between TARGIT technique and non-TARGIT technique.RESULTS: The cohort included 70 patients with cervical cancer who underwent 302 T&O procedures: 68 (23%) with TARGIT technique and 234 (77%) with non-TARGIT technique, which included 133 NN and 101 FN implants. TARGIT implants involved longer average procedure times (+6.3 minutes, p<0.0001). TARGIT implants achieved a higher mean high-risk CTV V100% than non-TARGIT implants (+4.4%, p=0.001) including for large tumors 30 cc or greater (+8.1%, p=0.002). Average D90 was 4.6 Gy higher and average D98 was 3.2 Gy higher for TARGIT technique compared to non-TARGIT technique (p=0.006 and p=0.02). Total treatment doses to rectum, bowel, and bladder were not significantly different for TARGIT versus non-TARGIT technique.CONCLUSION: The 3D-printed TARGIT approach to T&O brachytherapy achieved greater tumor coverage while sparing normal tissues, particularly for large tumor volumes, with only a slight increase in average procedure time. TARGIT represents a creative technological solution for increasing accessibility of advanced IC/IS brachytherapy technique for cervical cancer definitive radiation treatment.
View details for DOI 10.1016/j.ijrobp.2022.05.027
View details for PubMedID 35654306