Author: Chloe DiTusa, Panayiotis Mavroidis, Christopher W. Schneider, Sotirios Stathakis 👨🔬
Affiliation: Louisiana State University, Mary Bird Perkins Cancer Center, University of North Carolina 🌍
Purpose:
To calculate radiobiological metrics of daily dose delivered for head and neck (HN) patients using the daily cone beam CT (CBCT) to generate a pseudo CT (pCT). Moreover, this work compares the radiobiological metrics from dose distributions calculated using the Therapanacea AdaptBox and Elekta Monaco dose calculation algorithms.
Methods:
Four HN patients with treatment plans delivering 70 Gy with fractions ranging from 15 to 34 were selected. For each patient, daily CBCTs were converted to pCT using TheraPanacea’s AdaptBox software. Dose distributions were recalculated onto the pCTs using Monaco. Dose-volume histogram (DVH) data was extracted for PTVs and critical organs-at-risk (OARs) including the spinal cord, brachial plexus (bilateral), parotids (bilateral), mandible, brainstem, oral cavity, and larynx. Radiobiological metrics—P+, PB, and PI—were calculated for each fraction. A custom R code was developed to compare the metrics between systems by evaluating differences throughout the treatment course. Results were visualized to highlight both individual system trends and discrepancies.
Results:
Preliminary analysis of one patient revealed radiobiological metric differences as follows: maximum P+ difference of 0.15 (TheraPanacea > Monaco), maximum PI difference of -0.11 (Monaco > TheraPanacea), and maximum PB difference of 0.019. These differences occurred at different fractions, with variation across structures. The preliminary data suggest that TheraPanacea’s dose calculations align closely with Monaco’s. Analysis of additional patients is ongoing, with anticipated smaller differences based on initial gamma analysis.
Conclusion:
The initial findings indicate that TheraPanacea dose calculations demonstrates sufficient radiobiological similarity to Monaco for head and neck treatments. Further evaluation of the remaining patients will clarify the consistency of these results across varying treatment plans and fractionations, supporting potential clinical adoption of TheraPanacea as a comparable system for daily dose verification.