Development of an automated CBCT-based simulation-free platform for expedited palliative radiotherapy on a conventional linear accelerator.

BACKGROUND

Conventional approaches for emergent or expedited palliative radiotherapy (RT) involve the application of cumbersome vendor-provided solutions and/or multiple patient appointments to complete the RT workflow within a compressed timeframe.

PURPOSE

This report delineates the clinical development of an in-house, semi-automated Cone-beam computed tomography (CBCT)-based simulation-free platform for expedited palliative RT on conventional linacs, intended to supplant existing techniques employed at this institution.

METHODS

The internal software, termed SimFree Wizard (SFW), was engineered utilizing a C#-based application programming interface integrated within the treatment planning system (TPS). Generated scripts were compiled as stand-alone executables, with a graphical user interface (GUI) customized via an integrated development environment. The platform was conceived as a framework for accelerated CBCT-based RT, bypassing the requirement for standard simulation imaging. SFW employs full automation where feasible to minimize user intervention, supplemented by graphical instructions for tasks requiring manual execution. During development, relevant temporal metrics from 10 end-to-end tests for palliative spine RT were quantified. User feedback was solicited via a simple questionnaire assessing the overall platform usability. Automated in-house secondary verification software was developed for validation of the TPS-calculated monitor units (MUs).

RESULTS

The mean duration for workflow execution was 41:42 ± 3:18 [mm:ss] (range ∼37-46 min). SFW satisfactorily generated simple, multi-field CBCT-based 3D treatment plans within seconds following delineation of the desired treatment area. User feedback indicated enhanced usability compared to previously employed solutions. Validation of the secondary verification software demonstrated accurate results for palliative spine RT and other simple cases wherein the dose calculation point resides in a predominantly homogenous medium.

CONCLUSION

A novel in-house solution for expedited CBCT-based RT was successfully developed, facilitating completion of the entire workflow within approximately 1-hour or less for simple palliative/emergent scenarios. Overall, this application is expected to improve the quality and safety of palliative RT while greatly reducing workflow duration, thereby improving access to palliative care.