Author: Brook Byrd, Lisha Chen, Michael LaRiviere, Baozhu Lu, John Plastaras, Brian W Pogue, Emily Xiong, Timothy C. Zhu, Yifeng Zhu 👨🔬
Affiliation: Department of Radiation Oncology, University of Pennsylvania, University of Pennsylvania, University of Wisconsin - Madison 🌍
Purpose: For total skin electron therapy (TSET), achieving optimal dose distribution depends on precise patient positioning, which is often influenced by daily variability. Cherenkov imaging offers a valuable tool for real-time quality assurance of dose uniformity. This study aims to assess the effectiveness of multi-view Cherenkov imaging in evaluating cumulative surface dose distributions in TSET patients.
Methods: The Cherenkov emission was captured by three cameras positioned in the front and on the two sides of the target. The Cherenkov images were corrected, converted to 2D dose maps and projected onto the 3D object to acquire the 3D surface dose map. We conduct phantom experiments with an oblique solid water phantom and a cylindrical phantom to validate the combination of different views and the corrections, conversion of the Cherenkov intensity to dose. We have applied the method to patients and compared the projected result with Monte Carlo simulation and validated with in vivo dosimetry.
Results: The experiment result show that with the 3D dose could reconstructed using three 2D Cherenkov-dose maps with acceptable tolerance (10%) after the corrections. A retrospective study of 8 patients was done and demonstrated that the cumulative surface dose reconstructed from multiview Cherenkov images in good agreements (within 15% discrepancy) with IVD in perineum, top of the right shin, chest, left and right sides. Patient specific corrections factors are derived, and the 3D reconstructed Cherenkov-converted-dose are evaluated with the MC calculated dose.
Conclusion: Cherenkov imaging with proper corrections shows good potential for surface dose verification, offering a novel approach for daily patient positioning feedback and quality assurance in TSET.