A novel dose-based intra-preplan method for high-dose-rate brachytherapy in cervical cancer using modeling and...

This study presents the dose-based intra-preplan (DIP) method for intracavitary/interstitial brachytherapy (IC/ISBT) in cervical cancer, optimizing catheter configurations based on dose distribution. This study aimed to assess the DIP method's clinical feasibility and efficacy.

The DIP method incorporates the implant modeling function and the hybrid inverse planning optimization algorithm in Oncentra Brachy. Virtual applicator and catheter models were created and merged with patient-specific computed tomography images. Subsequently, an optimization algorithm was used to automatically determine the optimal catheter configuration-including the number, positions, and insertion depths. The workflow was retrospectively validated in 14 IC/ISBT patients treated with the Geneva applicators. Catheter configurations from the DIP and conventional intra-preplan (IP) methods were compared in terms of catheter number and dose-volume histogram (DVH) parameters for high-risk clinical target volume (CTV_HR) and organs at risk (OARs). To evaluate the optimality of the DIP-based configurations, DVH parameters were assessed after changing the number of catheters.

The DIP workflow was successfully established. Compared to the IP method, the DIP method achieved similar DVH parameters for both CTV_HR and OARs with significantly fewer catheters (p < 0.01). The addition of catheters did not significantly alter DVH parameters, while their reduction significantly compromised CTV_HR coverage (p < 0.01) and increased OAR doses (p < 0.05).

The DIP method enables patient-specific optimization of minimal catheter configurations and supports the broader implementation of high-quality IC/ISBT.