ESTRO 2024 - Abstract Book

S5353

Radiobiology - Tumour biology

ESTRO 2024

nerves and other surrounding normal tissues. Two patients treated with 1 mm margin demonstrated an even larger increase in BED 2.47 . Margins greater than 1 mm are likely to significantly increase the BED further. By including the impact of SLDR during treatment in the calculation of the BED for SRS treatment plans we have demonstrated the wide variation in BED and the inadequacy of the basic LQ model in quantifying these treatments.

Keywords: BED Vestibular Schwannomas

References:

1. Benedict SH, Lin PS, Zwicker RD, Huang DT, Schmidt-Ullrich RK. The biological effectiveness of intermittent irradiation as a function of overall treatment time: development of correction factors for linac-based stereotactic radiotherapy. Int J Radiat Oncol Biol Phys. 1997 37(4):765-769

2. Wang X, Xiong XP, Lu J, Zhu GP, He SQ, Hu CS, Ying HM. The in-vivo study of the radiobiologic effect of prolonged delivery time to tumor control in C57BL mice implanted with Lewis lung cancer. Radiat Oncol. 2011 Jan 12:6:4

3. Tuleasca C, Paddick I, Hopewell JW, Jones B, Millar WT, Hamdi H, Porcheron D, Levivier M, Regis J. Establishment of a therapeutic ratio for Gamma Knife radiosurgery of trigeminal neuralgia: the critical importance of biologically effective dose versus physical dose. World Neurosurg. 2020 134:e204-e213 4. Nesvick CL, Graffeo CS, Brown PD, Link MJ, Stafford SL, Foote RL, Laack NN, Pollock BE. The role of biological effective dose in predicting obliteration after stereotactic radiosurgery of cerebral arteriovenous malformations. Mayo Clin Proc. 2021 96(5):1157-1164 5. Graffeo CS, Donegan D, Erickson D, Brown PD, Perry A, Link MJ, Young WF, Pollock BE. The impact of insulin-like growth factor index and biologically effective dose on outcomes after stereotactic radiosurgery for acromegaly: cohort study. Neurosurgery 2020 87(3):538-546 6. Huo M, Rose M, van Prooijen M, Cusimano M, Laperriere N, Heaton R, Gentili F, Payne D, Shultz DB, Kongkham P, Kalia SK, Schwartz M, Bernstein M, Spears J, Zadeh G, Hodaie M, Tsang D. Importance of cobalt-60 dose rate and biologically effective dose on local control for intracranial meningiomas treated with stereotactic radiosurgery

7. Pop LA, Millar WT, van der Plas M, van der Kogel AJ. Radiation tolerance of rat spinal cord to pulsed dose rate (PDR- ) brachytherapy: the impact of differences in temporal dose distribution. Radiother Oncol. 2000 55(3):301-315

8. Millar WT, Hopewell JW, Paddick I, Lindquist C, Nordstrom H, Lidberg P, Garding J. The role of the concept of biologically effective dose (BED) in treatment planning in radiosurgery. Physica Medica 2015 31:627-633

9. Jones B, Hopewell JW. Modelling the influence of treatment time on the biological effectiveness of single radiosurgery treatments: derivation of "protective" dose modification factors. Br J Radiol 2019 92:20180111

10. Anthes VB, Schwartz M, Cusimano M, Radovanovic I, Kulkarni AV, Laperriere N, Payne D, Heaton R, van Prooijen M, Das S, Tsang DS. Effect of cobalt-60 treatment dose rate on arteriovenous malformation obliteration after stereotactic radiosurgery with Gamma Knife. Neurosurgery 2023 in press.