Time Driven Characterization of Tandem and Ring HDR Cervical Brachytherapy Workflow Process
Abstract
Purpose
HDR cervical brachytherapy requires continuous anesthesia and coordinated execution across multiple clinical teams, yet most workflows are described only by procedural sequence rather than temporal behavior. This study aims (1) to characterize the time required for major HDR workflow elements from applicator insertion through treatment completion, (2) to quantify variability and identify steps influenced by coordination rather than technical performance, and (3) to generate temporal descriptors that could support optimization, anesthesia tolerance, and training.
Methods
Sixty-five tandem-and-ring fractions performed under anesthesia were retrospectively analyzed. Procedural timestamps were extracted from anesthesia records, written directives, Oncentra TPS logs, MicroSelectron afterloader records, and the EHR, and mapped to discrete workflow tasks including anesthesia induction, applicator placement, CT imaging, HDR planning, plan check, treatment delivery, applicator removal, and recovery. A multidisciplinary swim-lane map depicted handoffs among anesthesia, radiation oncology, nursing, CT technologists, dosimetry, and physics. Five central HDR tasks: initial vital signs, CT imaging, HDR planning, physics plan check, and treatment delivery were normalized on a 0 - 1 scale to allow cross-task comparison while preserving distributional shape. Box-and-whisker plots, descriptive statistics, and ANOVA/Kruskal-Wallis testing evaluated variability patterns and coordination effects.
Results
Reconstructed timelines demonstrated substantial temporal heterogeneity. HDR planning exhibited the greatest dispersion, consistent with anatomy, applicator placement, and optimization strategy. Treatment delivery times clustered tightly, reflecting standardized source management and QA. CT imaging and plan check displayed intermediate variability influenced by workflow coordination. Swim-lane mapping identified asynchronous personnel arrival and paging delays during peak hours.
Conclusion
Efficiency in HDR cervical brachytherapy is jointly determined by technical execution and coordination under anesthesia. Translational opportunities include structured knowledge transfer, policy refinement, simulation-based training, and analytics platforms (e.g., ProKnow) to support verification and quality control. Temporal process maps may aid benchmarking, onboarding, and continuous improvement.