ESTRO meets Asia 2024 - Abstract Book

S341

Physics – Quality assurance and auditing

ESTRO meets Asia 2024

Distribution of various dose-volume characteristics is shown in Fig. 3. Hotspot values for brain and prostate plans are significantly (p<0.05) lower than for other disease sites.

There are ICRU-83 recommendations to keep HI as low as possible for 3DCRT and IMRT plans but, in comparison, for SBRT plans HI may be rather greater due to high dose gradients. In our study, the mean value for the homogeneity index was found to be 0.20 (Std. Dev. 0.05). There is a general recommendation for SBRT/SRS plans to keep CI lower than 1.20. The mean value for the conformity index was found to be 1.17 (Std. Dev. 0.07).

Conclusion:

Due to the unification applied in our hospital during the last years, the data demonstrated relatively low variability even having some site or planner specific features. Our standardization advanced due to the continued implementation of auto-contouring programs, treatment planning systems and QA automation software that allow to easily create templates for each step of the radiation treatment workflow. For example, organs nomenclature and dose-volume metrics can be easily pre-defined for planning and reporting. The amount of coherent clinical data will be significantly accelerated if a common standardization will be applied between different countries and institutes.

Keywords: SBRT, dose prescription, standardization,

References:

Das IJ, Yadav P, Andersen AD, et al. Dose prescription and reporting in stereotactic body radiotherapy: A multi institutional study. Radiother Oncol . 2023;182:109571. doi:10.1016/j.radonc.2023.109571

Schiff PB. Dose dissonance in radiation oncology: Consensus needed when prescribing dose in radiation therapy. Pract Radiat Oncol . 2017;7(6):e579-e580. doi:10.1016/j.prro.2017.04.018

Eaton DJ, Naismith OF, Henry AM. Need for consensus when prescribing stereotactic body radiation therapy for prostate cancer. Int J Radiat Oncol Biol Phys . 2015;91(1):239-241. doi:10.1016/j.ijrobp.2014.09.025

ICRU report 91: Prescribing, Recording, and reporting of Stereotactic Treatments with Small Photon Beams. 2017.

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Proffered Paper

Enhanced Collaboration in Physics QA for Radiotherapy in Japan: The Hiroshima Model

Shuichi Ozawa 1 , Minoru Nakao 1 , Hideharu Miura 1 , Masahiro Hayata 2 , Kenji Kanemoto 2 , Hiroki Takiguchi 2 , Kiyoshi Yamada 2 , Daisuke Kawahara 3 , Takeo Nakashima 4 , Yusuke Ochi 4 , Takuro Okumura 4 , Haruhide Kunimoto 5 , Atsushi Kawakubo 6 , Hayate Kusaba 6 , Hiroshige Nozaki 7 , Kosaku Habara 7 , Kosuke Hayashi 7 1 Division of Medical Physics, Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan. 2 Division of Radiological Technology, Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan. 3 Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan. 4 Division of Radiation Therapy, Department of Clinical Practice and Support, Hiroshima University Hospital,