Implementation and validation of a combined MRI-CT-based cervical cancer brachytherapy program using existing infrastructure

Abstract

Purpose: To describe the implementation of an MRI-CT-based cervical cancer brachytherapy (BT) program using existing infrastructure. To evaluate its impact on treatment planning.

Methods and materials: A step-wise method was used to design and implement three-dimensional-based planning. Prospective risk analysis was used to create a process map and planning protocol. To evaluate the program, charts of cervical cancer patients treated curatively between January 2013 and December 2014, with at least one MRI during BT planning, were reviewed. Dosimetric comparisons were made between prescription point used and that of the traditional Point A and between MRI-planned treatments and CT-planned treatments. They were evaluated for differences between plans as well as adherence to Groupe Européen de Curiethérapie-European Society for Radiotherapy & Oncology (GEC-ESTRO) recommendations for high-risk clinical target volume coverage and organs-at-risk constraints.

Results: Implementation of the MRI-CT planning program occurred using existing infrastructure. Key to the implementation was communication between departments and the use of a process map to document the workflow. Eighty percent of treatments were prescribed to a point other than Point A, there were no major differences between the MRI-planned and CT-planned (with MRI guidance) treatments, and GEC-ESTRO recommendations were met for target coverage and organs at risk dose constraints.

Conclusions: It was feasible to implement an MRI-CT-based cervical cancer BT planning program using existing infrastructure and that resulting plans meet GEC-ESTRO recommendations.

Keywords: Brachytherapy; CT; Cervical cancer; MRI; Process map; Risk analysis.