Comparison of three commercial methods of cone-beam computed tomography-based dosimetric analysis of head-and-neck patients with weight loss

• Published in: Journal of medical physics Vol. 47; no. 4; pp. 344 - 351
• Main Authors: Rathee, Satyapal, Burke, Benjamin, Heikal, Amr
• Format: Journal Article
• Language: English
• Published: India Wolters Kluwer India Pvt. Ltd 01.10.2022; Medknow Publications and Media Pvt. Ltd; Medknow Publications & Media Pvt. Ltd; Wolters Kluwer - Medknow; Wolters Kluwer Medknow Publications
• Subjects: Comparative analysis; Computed tomography; cone-beam computed tomography; Criteria; CT imaging; deformable registration; Deformation; Dosimetry; head and neck; Medical equipment and supplies industry; Medical test kit industry; Methods; Original; Planning; Spinal cord; Tomography; Weight loss; United States; weight loss; head and neck; Cone-beam computed tomography; deformable registration
• ISSN: 0971-6203; 1998-3913
• DOI: 10.4103/jmp.jmp_7_22

Purpose: This investigation compares three commercial methods of cone-beam computed tomography (CBCT)-based dosimetric analysis to a method based on repeat computed tomography (CT). Materials and Methods: Seventeen head-and-neck patients treated in 2020, and with a repeat CT, were included in the analyses. The planning CT was deformed to anatomy in repeat CT to generate a reference plan. Two of the CBCT-based methods generated test plans by deforming the planning CT to CBCT of fraction N using VelocityAI™ and SmartAdapt®. The third method compared directly calculated doses on the CBCT for fraction 1 and fraction N, using PerFraction™. Maximum dose to spinal cord (Cord_dmax) and dose to 95% volume (D95) of planning target volumes (PTVs) were used to assess "need to replan" criteria. Results: The VelocityAI™ method provided results that most accurately matched the reference plan in "need to replan" criteria using either Cord_dmax or PTV D95. SmartAdapt® method overestimated the change in Cord_dmax (6.77% vs. 3.85%, P < 0.01) and change in cord volume (9.56% vs. 0.67%, P < 0.01) resulting in increased false positives in "need to replan" criteria, and performed similarly to VelocityAI™ for D95, but yielded more false negatives. PerFraction™ method underestimated Cord_dmax, did not perform any volume deformation, and missed all "need to replan" cases based on cord dose. It also yielded high false negatives using the D95 PTV criteria. Conclusions: The VelocityAI™-based method using fraction N CBCT is most similar to the reference plan using repeat CT; the other two methods had significant differences.