Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-26T18:51:24.487Z Has data issue: false hasContentIssue false
  • English
  • Français

Using FFF beams to improve the therapeutic ratio of lung SBRT

Published online by Cambridge University Press:  30 July 2020

Oleg N. Vassiliev Open the ORCID record for Oleg N. Vassiliev [Opens in a new window] ,
Christine B. Peterson ,
Joe Y. Chang  and
Radhe Mohan
Oleg N. Vassiliev*
Affiliation:
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
Christine B. Peterson
Affiliation:
Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
Joe Y. Chang
Affiliation:
Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
Radhe Mohan
Affiliation:
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
*
Author for correspondence: Oleg N. Vassiliev, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX77030, USA. Tel: +1 713-745-7995. Fax: +1 713-563-6949. E-mail: onvassil@mdanderson.org
Get access Rights & Permissions [Opens in a new window]

Abstract

Aim:

The aim of this study was to investigate the extent to which lung stereotactic body radiotherapy (SBRT) treatment plans can be improved by replacing conventional flattening filter (FF) beams with flattening filter-free (FFF) beams.

Materials and methods:

We selected 15 patients who had received SBRT with conventional 6-MV photon beams for early-stage lung cancer. We imported the patients’ treatment plans into the Eclipse 13·6 treatment planning system, in which we configured the AAA dose calculation model using representative beam data for a TrueBeam accelerator operated in 6-MV FFF mode. We then created new treatment plans by replacing the conventional FF beams in the original plans with FFF beams.

Results:

The FFF plans had better target coverage than the original FF plans did. For the planning target volume, FFF plans significantly improved the D98, D95, D90, homogeneity index and uncomplicated tumour control probability. In most cases, the doses to organs at risk were lower in FFF plans. FFF plans significantly reduced the mean lung dose, V10, V20, V30, and normal tissue complication probability for the total lung and improved the dosimetric indices for the ipsilateral lung. For most patients, FFF beams achieved lower maximum doses to the oesophagus, heart and the spinal cord, and a lower chest wall V30.

Conclusions:

Compared with FF beams, FFF beams achieved lower doses to organs at risk, especially the lung, without compromising tumour coverage; in fact, FFF beams improved coverage in most cases. Thus, replacing FF beams with FFF beams can achieve a better therapeutic ratio.

Keywords

lung SBRTFFF beamstumor controlcomplication probability
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 20 , Issue 4 , December 2021 , pp. 419 - 425
Check for updates
Copyright
© The Author(s), 2020. 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

Hrbacek, J, Lang, S, Klock, S. Commissioning of photon beams from a filter-free linear accelerator and the accuracy of beam modelling using an anisotropic analytical algorithm. Int J Radiat Oncol Biol Phys 2011; 80: 1228–1237.CrossRefGoogle Scholar
Georg, D, Knöös, T, McClean, B. Current status and future perspective of flattening filter free photon beams. Med Phys 2011; 38: 12801293.CrossRefGoogle ScholarPubMed
Xiao, Y, Kry, SF, Popple, R et al. Flattening filter-free accelerators: a report from the AAPM therapy emerging technology assessment work group. J Appl Clin Med Phys 2015; 16: 12–29.CrossRefGoogle ScholarPubMed
Budgell, G, Brown, K, Cashmore, J et al. IPEM topical report 1: guidance on implementing flattening filter free (FFF) radiotherapy. Phys Med Biol 2016; 61: 83608394.CrossRefGoogle ScholarPubMed
Vassiliev, ON, Kry, SF, Chang, JY et al. Stereotactic radiotherapy for lung cancer using a flattening filter free Clinac. J Appl Clin Med Phys 2009; 10: 14–21.CrossRefGoogle ScholarPubMed
Boda-Heggemann, J, Mai, S, Fleckenstein, J et al. Flattening-filter-free intensity modulated breath-hold image-guided SABR (stereotactic ablative radiotherapy) can be applied in a 15 min treatment slot. Radiother Oncol 2013; 109: 505–509.CrossRefGoogle Scholar
Ong, CL, Dahele, M, Slotman, BJ et al. Dosimetric impact of the interplay effect during stereotactic lung radiation therapy delivery using flattening filter-free beams and volumetric modulated arc therapy. Int J Radiat Oncol Biol Phys 2013; 86: 743–748.CrossRefGoogle ScholarPubMed
Prendergast, BM, Fiveash, JB, Popple, RA et al. Flattening filter-free linac improves treatment delivery efficiency in stereotactic body radiation therapy. J Appl Clin Med Phys 2013; 14: 64–71.CrossRefGoogle ScholarPubMed
Gasic, D, Ohlhues, L, Brodin, NP 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
Lu, J, Lin, Z, Lin, P et al. Optimizing the flattening filter free beam selection in RapidArc®-based stereotactic body radiotherapy for stage I lung cancer. Br J Radiol 2015; 88: 20140827.CrossRefGoogle ScholarPubMed
Tambe, N, Fryer, A, Marsden, J. Determination of clinically appropriate flattening filter free (FFF) energy using treatment plans and delivery measurements. Biomed Phys Eng Express 2016; 2: 065016.CrossRefGoogle Scholar
Vassiliev, ON, Kry, SF, Wang, HC et al. Radiotherapy of lung cancers: FFF beams improve dose coverage at tumor periphery compromised by electronic disequilibrium. Phys Med Biol 2018; 63: 195007.CrossRefGoogle ScholarPubMed
Pokhrel, D, Halfman, M, Sanford, L. FFF-VMAT for SBRT of lung lesions: improves dose coverage at tumor-lung interface compared to flattened beams. J Appl Clin Med Phys 2019; 1: 1–10.Google Scholar
Navarria, P, Ascolese, AM, Mancosu, P et al. Volumetric modulated arc therapy with flattening filter free (FFF) beams for stereotactic body radiation therapy (SBRT) in patients with medically inoperable early stage non-small cell lung cancer (NSCLC). Radiother Oncol 2013; 107: 414–418.CrossRefGoogle Scholar
ICRU. International Commission on Radiation Units and Measurements Prescribing, recording, and reporting photon-beam intensity-modulated radiation therapy (IMRT). ICRU Report 83. J ICRU 2010; 10: 1–106.CrossRefGoogle Scholar
Chetty, IJ, Devpura, S, Liu, D et al. Correlation of dose computed using different algorithms with local control following stereotactic ablative radiotherapy (SABR)-based treatment of non-small-cell lung cancer. Radiother Oncol 2013; 109: 498–504.CrossRefGoogle ScholarPubMed
Webb, S, Nahum, AE. A model for calculating tumor control probability in radiotherapy including the effects of inhomogeneous distributions of dose and clonogenic cell density. Phys Med Biol 1993; 38: 653666.CrossRefGoogle Scholar
Guckenberger, M, Richter, A, Wilbert, J, Flentje, M, Partrige, M. Adaptive radiotherapy for locally advanced non-small-cell lung cancer does not underdose the microscopic disease and has the potential to increase tumor control. Int J Radiat Oncol Biol Phys 2011; 81: e275–e282.CrossRefGoogle Scholar
Selvaraj, J, Lebesque, J, Hope, A et al. Modeling radiation pneumonitis of pulmonary stereotactic body radiotherapy: the impact of a local dose–effect relationship for lung perfusion loss. Radiother Oncol 2019; 132: 142–147.CrossRefGoogle ScholarPubMed