ESTRO 2025 - Abstract Book

S4144

RTT - Patient care, preparation, immobilisation and IGRT verification protocols

ESTRO 2025

Material/Methods: The HDB used in this study is a commercially available product (ExaSkin de AnatGe, 1.7 g/cm³) characterized by its high density and matte surface, and was evaluated on anthropomorphic phantoms for breast and abdominal regions. Using Exactrac and AlignRT systems, postural lines were analyzed under various lighting conditions. Intentional displacements of the bolus (1 mm to 10 mm) were introduced to determine the system's ability to differentiate between patient and bolus misalignments. The HDB was also tested while secured with a Tubular Elastic Mesh Bandage (figure 2), commonly used in radiotherapy setups, to assess whether the bandage interfered with SGRT workflows, particularly in detecting postural lines and maintaini ng stable bolus placement.

Results: • The HDB provided stable and well-defined postural lines, allowing clear differentiation between patient and bolus surfaces. • Misalignments at the millimetric level were accurately detected without compromising patient positioning. • Unlike workflows with water-equivalent boluses, which typically require two SGRT acquisitions as recommended by publications in Medical Physics [3], the HDB allowed accurate alignment using a single acquisition, simplifying the setup process. • The use of the Tubular Elastic Mesh Bandage demonstrated no interference with SGRT systems or postural line detection, confirming its compatibility for securing the bolus without affecting workflow efficiency. Conclusion: The unique optical properties of the HDB provide a significant advantage in SGRT workflows, enabling single-step patient positioning and bolus alignment. The compatibility of the HDB with the Tubular Elastic Mesh Bandage further enhances its clinical utility, making it particularly suitable for scenarios such as Deep Inspiration Breath Hold (DIBH), where secure bolus placement and precise tracking are critical for treatment accuracy and efficiency. References: 1. Freislederer P, Batista V, Öllers M, et al. ESTRO-ACROP guideline on surface guided radiation therapy. Radiother Oncol. 2022;173:188–96. doi:10.1016/j.radonc.2022.05.026. 2. Li G, Lu W, O’Grady K, et al. A uniform and versatile surface ‐ guided radiotherapy procedure and workflow for high ‐ quality breast deep ‐ inspiration breath ‐ hold treatment in a multi ‐ center institution. J Appl Clin Med Phys. 2022;23(3). doi:10.1002/acm2.13511. 3. Kügele M et al. Surface guided radiotherapy improves breast cancer patient setup accuracy. J Appl Clin Med Phys. 2019;20(9):61–8. doi:10.1002/acm2.12700. 4. Wakabayashi K et al. Initial clinical experience of a novel shapeable bolus for radiotherapy. Cureus. 2024;16(4). doi:10.7759/cureus.57415. Keywords: SGRT, bolus