Trade-off in healthy tissue sparing of FLASH and fractionation in stereotactic proton therapy of lung lesions with transmission beams

被引：13

作者：

Habraken, Steven ^{[1
,2
,4
,5
]}

Breedveld, Sebastiaan ^{[1
]}

Groen, Jort ^{[1
,6
]}

Nuyttens, Joost ^{[1
,3
]}

Hoogeman, Mischa ^{[1
,2
]}

机构：

[1] Univ Med Ctr Rotterdam, Erasmus MC, Dept Radiotherapy, Canc Inst, Rotterdam, Netherlands

[2] Holland Proton Therapy Ctr, Dept Med Phys & Informat, Delft, Netherlands

[3] Holland Proton Therapy Ctr, Dept Radiat Oncol, Delft, Netherlands

[4] Erasmus MC, Dept Radiother apy Med Phys & Instrumentat, Postbus 2040, NL-3000 CA Rotterdam, Netherlands

[5] Erasmus MC, Dept Radiother apy Med Phys & Instrumentat, Dr Molewaterpl 40, NL-3015 GD Rotterdam, Netherlands

[6] Univ Amsterdam, Dept Radiat Oncol, Med Ctr, Amsterdam, Netherlands

来源：

RADIOTHERAPY AND ONCOLOGY | 2022年 / 175卷

关键词：

Stereotactic lung treatment; Proton therapy; Flash radiotherapy; Radiobiological modeling; Treatment planning;

D O I：

10.1016/j.radonc.2022.08.015

中图分类号：

R73 [肿瘤学];

学科分类号：

100214 ;

摘要：

Purpose and objective: Besides a dose-rate threshold of 40-100 Gy/s, the FLASH effect may require a dose > 3.5-7 Gy. Even in hypofractioned treatments, with all beams delivered in each fraction (ABEF), most healthy tissue is irradiated to a lower fraction dose. This can be circumvented by single-beamper-fraction (SBPF) delivery, with a loss of healthy tissue sparing by fractionation. We investigated the trade-off between FLASH and loss of fractionation in SBPF stereotactic proton therapy of lung cancer and determined break-even FLASH-enhancement ratios (FERs).Materials and Methods: Treatment plans for 12 patients were generated. GTV delineations were available and a 5 mm GTV-PTV margin was applied. Equiangular arrangements of 3, 5, 7, and 9 244 MeV proton transmission beams were used. To facilitate SBPF, the number of fractions was equal to the number of beams. Iso-effective fractionation schedules with a single field uniform dose prescription were used: D95%,PTV = 100%Dpres per beam. All plans were evaluated in terms of dose to lung and conformity of dose to target of FLASH-enhanced biologically equivalent dose (EQD2).Results: Compared to ABEF, SBPF resulted in a median increase of EQD2mean to healthy lung of 56%, 58%, 55% and 54% in plans with 3, 5, 7 and 9 fractions respectively and of 236%, 78%, 50% and 41% in V100% EQD2, quantifying conformity. This can be compensated for by FERs of at least 1.28, 1.32, 1.30 and 1.23 respectively for EQD2mean and 1.29, 1.18, 1.28 and 1.15 for V100%,EQD2.Conclusion: A FLASH effect outweighing the loss of fractionation in SBPF may be achieved in stereotactic lung treatments. The trade-off with fractionation depends on the conditions under which the FLASH effect occurs. Better understanding of the underlying biology and the impact of delivery conditions is needed.(c) 2022 The Authors. Published by Elsevier B.V. Radiotherapy and Oncology 175 (2022) 231-237

引用

页码：231 / 237

页数：7

共 4 条

[1] The effects of radiation therapy fractionation on the sparing of healthy tissue in FLASH radiotherapy
Del Debbio, F.
Bertilacchi, M. S.
Giannini, N.
Gadducci, G.
Fuentes, T.
Cavalieri, A.
Paiar, F.
Capaccioli, S.
Di Martino, F.
Martini, C.
Da Pozzo, E.
FEBS OPEN BIO, 2024, 14 : 455 - 455
[2] Healthy tissue sparing in proton therapy of lung tumors using statistically sound robust planning
Badiu, V.
Souris, K.
Buti, G.
Villarroel, E. Borderias
Lambrecht, M.
Sterpin, E.
RADIOTHERAPY AND ONCOLOGY, 2022, 170 : S1285 - S1286
[3] Improved healthy tissue sparing in proton therapy of lung tumors using statistically sound robust optimization and evaluation
Badiu, Vlad
Souris, Kevin
Buti, Gregory
Villarroel, Elena Borderias
Lambrecht, Maarten
Sterpin, Edmond
PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS, 2022, 96 : 62 - 69
[4] Single-fraction 34 Gy Lung Stereotactic Body Radiation Therapy Using Proton Transmission Beams: FLASH-dose Calculations and the Influence of Different Dose-rate Methods and Dose/Dose-rate Thresholds
van Marlen, Patricia
Verbakel, Wilko F. A. R.
Slotman, Ben J.
Dahele, Max
ADVANCES IN RADIATION ONCOLOGY, 2022, 7 (04)

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