Quantifying the effect of eccentric ruthenium plaque placement on tumor volume dose
- Author(s)
- Flanagan, JPM; Udovenya, WHF; Astrahan, MA; McKay, D; Phillips, C; McKenzie, JD; O'Day, R; Fog, LS;
- Details
- Publication Year 2023,Volume 15,Issue #6,Page 442-447
- Journal Title
- Journal of Contemporary Brachytherapy
- Publication Type
- Research article
- Abstract
- PURPOSE: Ruthenium-106 brachytherapy is a common treatment for small to medium-sized uveal melanomas. In certain clinical contexts, plaques may be placed eccentrically to tumor center. The effect of plaque decentration, a common radiation dose measurement in radiotherapy: D(98%), the percentage of the tumor volume receiving at least 98% of the prescribed dose (a commonly used term in radiation oncology), is unknown. We investigated this using two commonly used plaques (CCA and CCB; Eckert & Ziegler, BEBIG GmbH) in silico. MATERIAL AND METHODS: Using a Plaque Simulator (Eye Physics) plaque modelling software, treatment time required to deliver 100 Gy D(98%) with central plaque placement was calculated for both plaque models, treating tumors with basal dimensions of 10 mm (CCB plaque only) and 7 mm (CCA and CCB plaques), and a range of thicknesses. D(98%) was calculated for plaque-tumor edge distances of 0-5 mm. Additionally, we defined minimum plaque-tumor edge distances, at which D(98%) fell by 10% and 5% (safety margins). RESULTS: D(98%) decreased as plaque-tumor edge distance decreased, i.e. as plaque eccentricity increased. Minor (< 1 mm) plaque decentration caused minimal D(98%) changes across tumor thicknesses. Safety margins did not follow a consistent pattern. CONCLUSIONS: Eccentric plaque placement reduces the radiation dose delivered to choroidal tumors. Both tumor (thickness, diameter) and plaque (size, location) characteristics are important D(98%) modulators. Further investigation of the effect of these characteristics and dose to organs at risk is essential.
- Department(s)
- Radiation Oncology
- PubMed ID
- 38230400
- Publisher's Version
- https://doi.org/10.5114/jcb.2023.133614
- Open Access at Publisher's Site
https://doi.org/10.5114/jcb.2023.133614- Terms of Use/Rights Notice
- Refer to copyright notice on published article.
Creation Date: 2024-08-20 06:08:11
Last Modified: 2024-08-20 06:56:56