Over the past several decades, improvements in cancer treatments and interventions have increased the rate of positive patient outcomes, with more patients than ever surviving their initial cancer diagnoses. This means, in turn, that more patients are returning for retreatment of primary cancers or treatment for new incidents of primary cancer.
In a 2023 study, approximately 24% of patients across 8 clinics were undergoing retreatment or palliative reirradiation. Recent progress in imaging accuracy, treatment delivery options, and combined treatments has made retreatment regimens easier, but there remains a call for consistent guidelines for reporting, decision-making, and patient-centered care around these cases.
Retreatment cases come with unique hurdles that complicate radiotherapy planning workflows. Some examples include:
Anatomical changes - Over time, patient anatomies change due to weight loss, repositioning, or other health issues. It is critical to track organ-at-risk (OAR) anatomical changes in order to accurately plan a retreatment dose.
Different image datasets - Not all patients return to the clinic where they originally received treatment. Image registration from multiple sources can be difficult to combine, but it is necessary to follow image datasets over time to trace the anatomical changes mentioned above.
Variable treatment intervals - Retreatment may occur anywhere from weeks to years after the initial treatment. With organ-specific recovery rates and ever-evolving recommendations for optimal dose planning, it’s essential to monitor the cumulative dose delivered to a patient over time.
Unique fractionation schemes - Depending on the clinic or primary tumor type, different fractionation schemes may be applied when planning treatment. Understanding how BED/EQD2 calculations impact delivered dose is important for ensuring patient safety.
Tissue-specific recovery rates - Organs and/or tissues impacted by the initial radiotherapy treatment recover at varying rates. For example, liver tissue recovers much faster compared to lung tissue. Reirradiation of OARs will impact these tissues differently over time. At the University of Michigan, clinicians have published extensive data studying the organ-specific recovery rates for different OARs.
Addressing the challenges of reirradiation requires more than a single calculation. Clinicians must understand how anatomy has changed, align prior and current imaging, evaluate cumulative dose, and account for biological effects across treatment courses. AutoContour and ClearCheck provide complementary tools to support that process.
AutoContour provides rigid and deformable image registration tools to help align prior and current imaging, even when anatomy or patient positioning differs between scans. Registration QA tools, including grid and heat map overlays, let clinicians review the deformation and visualize anatomical changes over time.
AutoContour offers 520+ guideline-aligned AI models to accelerate contour generation across retreatment datasets. The latest update adds mediastinal lymph nodes, EPTN Brain MR structures, and abdominal MR structures, as well as new and updated options for the head and neck, chest, abdomen, and pelvis, expanding coverage across treatment sites and imaging modalities.
Once prior and current treatment information is combined, ClearCheck helps your team evaluate the cumulative impact of multiple treatment courses. In addition to previously available plan sum tables that allow for multiple registration sources, ClearCheck’s latest features include:
Automatically applied organ-specific recovery factors
Visualization tools for BED/EQD2 doses
Conservative dose remainder table
Reference and admin tables for summed treatments
BED/EQD2 reference equations within ClearCheck for at-a-glance verification
Plus, apply constraint, structure*, plan*, prescription*, and collision checks to all your retreatment plans. ClearCheck also enables easy report generation for printing and documentation.
Together, AutoContour and ClearCheck provide valuable tools for reviewing prior and current patient anatomy and creating better-informed plans for retreatment cases.
Retreatment cases will always require careful clinical judgment. Understanding what came before and how it impacts what can safely come next shouldn’t require piecing together information manually. New tools are required to address the associated challenges of retreatment and satisfy the growing need for rigorous, reproducible approaches to planning for these cases. AutoContour and ClearCheck help provide added clarity and precision to planning for reirradiation treatments.
If you’re interested in learning how Radformation tools can help you approach retreatment with clarity, contact our team of experts to schedule a personalized demo today.
*Some features are limited or unavailable with DICOM functionality.