Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 May 13:22:85-90.
doi: 10.1016/j.phro.2022.05.003. eCollection 2022 Apr.

Comparing treatment uncertainty for ultra- vs. standard-hypofractionated breast radiation therapy based on in-vivo dosimetry

Yawo A C Fiagan  1   2 , Evy Bossuyt  1 , Melanie Machiels  1   3 , Daan Nevens  1   3 , Charlotte Billiet  1   3 , Philip Poortmans  1   3 , Thierry Gevaert  2   4 , Dirk Verellen  1   3
Affiliations

Comparing treatment uncertainty for ultra- vs. standard-hypofractionated breast radiation therapy based on in-vivo dosimetry

Yawo A C Fiagan et al. Phys Imaging Radiat Oncol. .

Abstract

Background and purpose: Postoperative ultrahypofractionated radiation therapy (UHFRT) in 5 fractions (fx) for breast cancer patients is as effective and safe as conventionally hypofractionated RT (HFRT) in 15 fx, liberating time for higher-level daily online Image-Guided Radiation Therapy (IGRT) corrections. In this retrospective study, treatment uncertainties occurring in patients treated with 5fx (5fx-group) were evaluated using electronic portal imaging device (EPID)-based in-vivo dosimetry (EIVD) and compared with the results from patients treated with conventionally HFRT (15fx-group) to validate the new technique and to evaluate if the shorter treatment schedule could have a positive effect on the treatment uncertainties.

Materials and methods: EPID-based integrated transit dose images were acquired for each treatment fraction in the 5fx-group (203 patients) and on the first 3 days of treatment and weekly thereafter in the 15fx-group (203 patients). A total of 1015 EIVD measurements in the 5fx-group and 1144 in the 15fx-group were acquired. Of the latter group, 755 had been treated with online IGRT correction (i.e., Online-IGRT 15fx-group).

Results: In the 15fx-group 12.0% of fractions failed (FFs) compared to 3.8% in the 5fx-group and 6.9% in the online-IGRT 15fx-group. Causes for FFs in the 15fx-group compared with the 5fx-group were patient positioning (7.4% vs. 2.2%), technical issues (3.1% vs. 1.2%) and breast swelling (1.4% vs. 0.5%). In the online-IGRT 15fx-group, 2.5% were attributed to patient positioning, 3.8% to technical issues and 0.5% to breast swelling.

Conclusions: EIVD demonstrated that UHFRT for breast cancer results in less FFs compared to standard HFRT. A large proportion of this decrease could be explained by using daily online IGRT.

Keywords: Automated treatment delivery verification; Early breast cancer; In-vivo dosimetry; Ultrahypofractionated radiation therapy.

PubMed Disclaimer

Conflict of interest statement

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors have an on-going scientific collaboration with Sun Nuclear Corporation.

Figures

Fig. 1
Fig. 1
Schematic overview of the number of EIVD measurements in the DIBH/non-DIBH 5fx-group (online IGRT) in light blue color and DIBH/non-DIBH 15fx-group in brown color (online IGRT in green color and offline IGRT in dark blue color). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
Fig. 2
Fig. 2
Causes of failed fractions in the 5fx-group, 15fx-group and online-IGRT 15fx-group: patient positioning, technical issues and breast swelling.
Fig. 3
Fig. 3
Causes of failed fractions in the DIBH subgroups: patient positioning, technical issues and breast swelling.
Fig. 4
Fig. 4
Causes of failed fractions in the non-DIBH subgroups: patient positioning, technical issues and breast swelling.
See this image and copyright information in PMC

References

    1. Zhu T.C., Stathakis S., Clark J.R., Feng W., Georg D., Holmes S.M., et al. Report of AAPM Task Group 219 on independent calculation-based dose/MU verification for IMRT. Med Phys. 2021;48:e808–e829. doi: 10.1002/mp.15069. - DOI - PubMed
    1. Miften M, Olch A, Mihailidis D, Moran J, Pawlicki T, Molineu A, et al. Tolerance limits and methodologies for IMRT measurement-based verification QA: recommendations of AAPM Task Group No. 218. Med Phys. 2018; 45:e53-e83. https://doi.org/10.1002/mp.12810. - PubMed
    1. MacDougall N.D., Graveling M., Hansen V.N., Brownsword K., Morgan A. In vivo dosimetry in UK external beam radiotherapy: current and future usage. Br J Radiol. 2017;90 doi: 10.1259/bjr.20160915. - DOI - PMC - PubMed
    1. Kang S., Li J., Ma J., Zhang W., Liao X., Qing H., et al. Evaluation of interfraction setup variations for postmastectomy radiation therapy using EPID-based in vivo dosimetry. J Appl Clin Med Phys. 2019;20:43–52. doi: 10.1002/acm2.12712. - DOI - PMC - PubMed
    1. Mijnheer B., Beddar S., Izewska J., Reft C. In vivo dosimetry in external beam radiotherapy. Med Phys. 2013;40 doi: 10.1118/1.4811216. - DOI - PubMed

LinkOut - more resources