Hostname: page-component-8448b6f56d-tj2md Total loading time: 0 Render date: 2024-04-24T05:22:14.070Z Has data issue: false hasContentIssue false
  • English
  • Français

Flattening filter free Stereotactic radiosurgery for brain metastases using dynamic conformal arcs: 6 MV or 10 MV?

Published online by Cambridge University Press:  18 January 2021

Glenn Whitten ,
Ursula Daly ,
Candice D. McCallum ,
Jackie Harney ,
David Conkey ,
Tom Flannery ,
Denise M. Irvine ,
Christina Skourou ,
Alan R. Hounsell  and
Conor K. McGarry Open the ORCID record for Conor K. McGarry [Opens in a new window]
Glenn Whitten
Affiliation:
Radiotherapy Physics, Belfast City Hospital, Belfast Health & Social Care Trust, Belfast, UK
Ursula Daly
Affiliation:
Radiotherapy Physics, Belfast City Hospital, Belfast Health & Social Care Trust, Belfast, UK
Candice D. McCallum
Affiliation:
Radiotherapy Physics, Belfast City Hospital, Belfast Health & Social Care Trust, Belfast, UK
Jackie Harney
Affiliation:
Clinical Oncology, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
David Conkey
Affiliation:
Clinical Oncology, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK
Tom Flannery
Affiliation:
Department of Neurosurgery, Royal Victoria Hospital, Belfast Health & Social Care Trust, Belfast, UK
Denise M. Irvine
Affiliation:
Radiotherapy Physics, Belfast City Hospital, Belfast Health & Social Care Trust, Belfast, UK
Christina Skourou
Affiliation:
St. Luke’s Radiation Oncology Centre Beaumont Hospital, Beaumont, Dublin 9, Ireland
Alan R. Hounsell
Affiliation:
Radiotherapy Physics, Belfast City Hospital, Belfast Health & Social Care Trust, Belfast, UK The Patrick G Johnston Centre for Cancer Research, Queen’s University of Belfast, Belfast, UK
Conor K. McGarry*
Affiliation:
Radiotherapy Physics, Belfast City Hospital, Belfast Health & Social Care Trust, Belfast, UK The Patrick G Johnston Centre for Cancer Research, Queen’s University of Belfast, Belfast, UK
*
Author for correspondence: Conor K. McGarry, Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast City Hospital, Belfast, UK, BT9 7AB. E-mail: conor.mcgarry@belfasttrust.hscni.net
Get access Rights & Permissions [Opens in a new window]

Abstract

Introduction:

Stereotactic radiosurgery (SRS) has proven itself as an effective tool in the treatment of intracranial lesions. Image-guided high dose single fraction treatments have the potential to deliver ablative doses to tumours; however, treatment times can be long. Flattening filter free (FFF) beams are available on most modern linacs and offer a higher dose rate compared to conventional flattened beams which should reduce treatment times. This study aimed to compare 6 MV FFF and 10 MV FFF to a 6 MV flattened beam for single fraction dynamic conformal arc SRS for a Varian Truebeam linac.

Materials and methods:

In total, 21 individual clinical treatment plans for 21 brain metastases treated with 6 MV were retrospectively replanned using both 6 MV FFF and 10 MV FFF. Plan quality and efficiency metrics were evaluated by analysing dose coverage, dose conformity, dose gradients, dose to normal brain, beam-on-time (BOT), treatment time and monitor units.

Results:

FFF resulted in a significant reduction in median BOT for both 6 MV FFF (57·9%; p < 0·001) and 10 MV FFF (76·3%; p < 0·001) which led to reductions in treatment times of 16·8 and 21·5% respectively. However, 6 MV FFF showed superior normal brain dose sparing (p < 0·001) and dose gradient (p < 0·001) compared to 10 MV FFF. No differences were observed for conformity.

Conclusion:

6 MV FFF offers a significant reduction in average treatment time compared to 6 MV (3·7 minutes; p = 0·002) while maintaining plan quality.

Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 21 , Issue 3 , September 2022 , pp. 328 - 334
Check for updates
Copyright
© The Author(s), 2021. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Sheehan, J P, Yen, C, Lee, C, Loeffler, J S. Cranial Stereotactic Radiosurgery: Current Status of the Initial Paradigm Shifter. J Clin Oncol 2014; 32 (26): 2836–2846.CrossRefGoogle ScholarPubMed
Lippitz, B, Lindquist, C, Paddick, I, Peterson, D, O’Neill, K, Beaney, R. Stereotactic radiosurgery in the treatment of brain metastases: the current evidence. Cancer Treatment Rev 2013; 40 (1): 48–59.CrossRefGoogle ScholarPubMed
De Salles, A A, Gorgulho, A A, Pereira, J L, McLaughlin, N. Intracranial stereotactic radiosurgery: concepts and techniques. Neurosurg Clin N Am 2013; 24 (4): 491–498.CrossRefGoogle ScholarPubMed
Hoogeman, M S, Nuyttens, J J, Levendag, P C, Heijmen, B J N. Time Dependence of Intrafraction Patient Motion Assessed by Repeat Stereoscopic Imaging. Int Radiat Oncol 2008; 70 (2): 609–618.CrossRefGoogle ScholarPubMed
Cashmore, J. The characterization of unflattened photon beams from a 6 MV linear accelerator. Phys Med Biol 2009; 53 (7): 1933–1946.CrossRefGoogle Scholar
Kragl, G, Baier, F, Lutz, S et al. Flattening filter free beams in SBRT and IMRT: dosimetric assessment of peripheral doses. Med Phys 2011; 21: (2): 91–101.Google ScholarPubMed
Georg, D, Knöös, T, McClean, B. Current status and future perspective of flattening filter free photon beams. Med Phys 2011; 38 (3): 1280–1293.CrossRefGoogle ScholarPubMed
Fogliata, A, Fleckenstein, J, Schneider, F et al. Flattening filter free beams from TrueBeam and Versa HD units: evaluation of the parameters for quality assurance. Med Phys 2016; 43 (1): 205.CrossRefGoogle ScholarPubMed
Dimitriadis, A, Kirkby, K J, Nisbet, A, Clark, C H. Current status of cranial stereotactic radiosurgery in the UK. Br J Radiol 2016; 89: 20150452.CrossRefGoogle ScholarPubMed
Rieber, J, Tonndorf-Martini, E, Schramm, O et al. Radiosurgery with flattening-filter-free techniques in the treatment of brain metastases. Strahlenther Onkol 2016; 192: 789–796.CrossRefGoogle ScholarPubMed
Youqun, L, Shanyu, C, Changdong, X et al. Dosimetric superiority of flattening filter free beams for single-fraction stereotactic radiosurgery in single brain metastasis. Oncotarget 2017; 8 (21): 35272–35279.Google Scholar
Stieler, F, Fleckenstein, J, Simeonova, A, Wenz, F, Lohr, F. Intensity modulated radiosurgery of brain metastases with flattening filter-free beams. Radiother Oncol 2013; 109: 448–451.CrossRefGoogle ScholarPubMed
Abacioglu, U, Ozen, Z, Yilmaz, M et al. Critical appraisal of RapidArc radiosurgery with flattening filter free photon beams for benign brain lesions in comparison to GammaKnife: a treatment planning study. Radiat Oncol 2010; 9: 119.CrossRefGoogle Scholar
Gasic, D, Ohlhues, L, Brodin, N P et al. A treatment planning and delivery comparison of volumetric modulated arc therapy with or without flattening filter for gliomas, brain metastases, prostate, head/neck and early stage lung cancer. Acta Oncol 2014; 53 (8): 1005–1011.CrossRefGoogle ScholarPubMed
Minniti, G, Capone, L, Alongi, F et al. Initial Experience With Single-Isocenter Radiosurgery to Target Multiple Brain Metastases Using an Automated Treatment Planning Software: Clinical Outcomes and Optimal Target Volume Margins Strategy. Adv Radiat Oncol 2020; 5 (5): 856–864.CrossRefGoogle ScholarPubMed
Kirkpatrick, J P, Wang, Z, Sampson, J H et al. Defining the optimal planning target volume in image-guided stereotactic radiosurgery of brain metastases: results of a randomized trial. Int J Radiat Oncol Biol Phys 2015; 91 (1): 100–108.CrossRefGoogle ScholarPubMed
Lawrence, Y R, Li, XA, Naqa el, I et al. Quantitative analyses of normal tissue effects in the clinic (QUANTEC): radiation dose-volume effects in the brain. Int J Radiat Oncol Biol Phys 2010; 76: S20–S27.CrossRefGoogle Scholar
Mayo, C, Martel, M K, Marks, L B, Flickinger, J, Nam, J, Kirkpatrick, J. Radiation dose-volume effects of optic nerves and chiasm, Int J Radiat Oncol Biol Phys 2010; 76; S28–S35.CrossRefGoogle ScholarPubMed
Mayo, C, Yorke, E, Merchant, T E. Radiation associated brainstem injury. Int J Radiat Oncol Biol Phys 2010; 76: S36–S41.CrossRefGoogle ScholarPubMed
Paddick, I. A simple scoring ratio to index the conformity of radiosurgical treatment plans. Technical note. J Neurosurg 2000; 93 (3): 219–222.CrossRefGoogle ScholarPubMed
Paddick, I, Lippitz, B. A simple dose gradient measurement tool to complement the conformity index. J Neurosurg 2006; 105: S194–S201.CrossRefGoogle ScholarPubMed
Dang, T M, Peters, M J, Hickey, B, Semciw, A. Efficacy of flattening-filter-free beam in stereotactic body radiation therapy planning and treatment: a systematic review with meta-analysis. J Med Imaging Radiat Oncol 2017; 61: 379–387.CrossRefGoogle ScholarPubMed
Mohamed Yoosuf, A B, Jeevandram, P, Whitten, G, Workman, G, McGarry, C K. Verification of high-dose-rate brachytherapy treatment planning dose distribution using liquid filled ionisation chamber array. J Contemp Brachytherapy 2018; 10 (2): 142–154.CrossRefGoogle Scholar
Lang, S, Shrestha, B, Graydon, S et al. Clinical application of flattening filter free beams for extracranial stereotactic. Radiotherapy. Radiother Oncol 2013; 106: 255–259.CrossRefGoogle ScholarPubMed
Hsu, S M, Lai, Y C, Jeng, C C, Tseng, C Y. Dosimetric comparison of different treatment modalities for stereotactic radiotherapy. Radiat Oncol 2017; 16:12 (1): 155.CrossRefGoogle ScholarPubMed
Blonigen, B J, Steinmetz, R D, Levin, L, Lamba, M A, Warnick, R E, Breneman, J C. Irradiated volume as a predictor of brain radionecrosis after linear accelerator stereotactic radiosurgery. Int J Radiat Oncol Biol Phys 2010; 77: 996–1001.CrossRefGoogle ScholarPubMed
Kragl, G, af Wetterstedt, S, Knäusl, B et al. Dosimetric characteristics of 6 and 10MV unflattened photon beams. Radiother Oncol 2009; 93 (1): 141–146.CrossRefGoogle ScholarPubMed
Dzierma, Y, Nuesken, F G, Palm, J, Licht, N P, Ruebe, C. Planning study and dose measurements of intracranial stereotactic radiation surgery with a flattening filter free linac. Pract Radiat Oncol 2014; 4: e109–e116.CrossRefGoogle ScholarPubMed
Wang, J Z, Rice, R, Mundt, A J, Sandhu, A, Murphy, K T. Feasibility and advantages of using flattening filter-free mode for radiosurgery of multiple brain lesions. Pract Radiat Oncol 2012; 2 (4): e165–e171.CrossRefGoogle ScholarPubMed