Image-Based Approaches to Interstitial Brachytherapy

For patients with tumors where the dose distribution of standard gynecologic brachytherapy applicators does not adequately cover the area at risk, interstitial brachytherapy represents an excellent alternative. After completion of external beam radiation, interstitial brachytherapy escalates the radiation dose to the regions of remaining gross residual disease for patients with all gynecologic malignancies. Interstitial catheters, placed either through a perineal template or free-hand, provide high-dose regions of radiation directly in the target. The use of 3D imaging before, during and after insertion, with ultrasound, CT, MRI, or PET scanning, results in an increase in accuracy that may change the total number of inserted catheters, may results in a higher degree of dose conformality and avoidance of normal tissues and may improve patient outcomes.