In Vivo Dosimetry for Cied Management – Is It Really Needed? 📝

Author: Anthony J. Doemer, Aharon Feldman, Stephen J. Gardner, Brett M. Miller, Benjamin Movsas, Farzan Siddiqui, Chadd Smith, Kundan S Thind, Kyle Verdecchia 👨‍🔬

Affiliation: Henry Ford Health 🌍

Abstract:

Purpose: To evaluate the efficacy of calculation-only approach for CIED risk-level assessment.
Methods: A total of 86 patients were included in this retrospective analysis. For each patient, in vivo dosimetry measurements using OSLD were compared to calculated doses (based on TPS calculated dose and estimate of CBCT imaging dose for relevant patients). Comparison of OSLD and calculated doses were structured as follows:(1)direct comparison of absolute dose and percent difference for measurement/calculation,(2)comparison of TG-203 risk-level assessment for measured/calculated doses, and (3)sensitivity/positive-predictive-value assessment of each method for TG-203 risk level assessment.
Results: For all cases, the calculation-based approach yielded a risk level that was equivalent to(or more) conservative than the risk level from OSLD measurement. For 79 of 86 patients (91.9%), the calculated and measured doses provided the same risk level. For 7 of 86 patients (8.1%), the calculated dose yielded the more conservative risk level. The mean difference between calculated/measured per-fraction-doses was 0.1±3.7cGy. Among all dose levels, the dose difference per fraction was within 2.5cGy for ~67% of cases and within 5cGy for ~88% of cases. When examining the concordance between calculated/measured doses, a distinction was observed between low dose level group (calculated dose<150cGy) and moderate/high dose level group(calculated dose>150cGy). In low dose category, TPS doses were lower compared to OSLD measured doses, (-0.6±3.3cGy). Conversely, within the moderate/high dose category, TPS doses were larger compared to OSLD-measured doses (3.1±3.9cGy). In terms of overall case distribution based on the 150cGy dose threshold: 17 of 86 cases (19.8%) were in the higher dose category (>150cGy) and 69 of 86 cases (80.2%) were in the lower dose category. The calculation-based dose estimate provided a sensitivity of 1.00 with a positive predictive value of 0.92.
Conclusion: The use of calculation-only approach has the potential to reduce workload while maintaining the efficacy of risk-level assessment for patients with CIED.

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