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 Mar;198(3):229-235.
doi: 10.1007/s00066-021-01839-5. Epub 2021 Sep 3.

Breast clinical target volume: HU-based glandular CTVs and ESTRO CTVs in modern and historical radiotherapy treatment planning

Marciana Nona Duma  1 , Theresa Kulms  2 , Stefan Knippen  2 , Tobias Teichmann  2 , Andrea Wittig  2
Affiliations

Breast clinical target volume: HU-based glandular CTVs and ESTRO CTVs in modern and historical radiotherapy treatment planning

Marciana Nona Duma et al. Strahlenther Onkol. 2022 Mar.

Abstract

Purpose: The current study aimed to compare contouring of glandular tissue only (gCTV) with the clinical target volume (CTV) as defined according to European Society for Radiotherapy and Oncology (ESTRO) guidelines (eCTV) and historically treated volumes (marked by wire and determined by palpation and anatomic landmarks) in breast cancer radiotherapy.

Methods: A total of 56 consecutive breast cancer patients underwent treatment planning based solely on anatomic landmarks/wire markings ("wire based"). From these treatment plans, the 50% and 95% isodoses were transferred as structures and compared to the following CT-based volumes: eCTV; a Hounsfield unit (HU)-based automatic contouring of the gCTV; and standardized planning target volumes (PTVs) generated with 1‑cm safety margins (resulting in the ePTVs and gPTVs, respectively).

Results: The 95% isodose volume of the wire-based plan was larger than the eCTV by 352.39 ± 176.06 cm3 but smaller than the ePTV by 157.58 ± 189.32 cm3. The 95% isodose was larger than the gCTV by 921.20 ± 419.78 cm3 and larger than the gPTV by 190.91 ± 233.49 cm3. Patients with larger breasts had significantly less glandular tissue than those with small breasts. There was a trend toward a lower percentage of glandular tissue in older patients.

Conclusion: Historical wire and anatomic landmarks-based treatment planning sufficiently covers the glandular tissue and the theoretical gPTV generated for the glandular tissue. Modern CT-based CTV and PTV definition according to ESTRO results in a larger treated volume than the historical wire-based techniques. HU-standardized glandular tissue contouring results in a significantly smaller CTV and might be an option for reducing the treatment volume and improving reproducibility of contouring between institutions.

Keywords: Breast cancer; Breast-conserving surgery; Radiation coverage; Radiotherapy planning, computer-assisted; Radiotherapy, adjuvant.

PubMed Disclaimer

Conflict of interest statement

M.N. Duma, T. Kulms, S. Knippen, T. Teichmann, and A. Wittig declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Exemplary contouring of the clinical target volume (CTV) defined by the European Society for Radiotherapy and Oncology guidelines (eCTV) and the glandular portion of the CTV (gCTV) for a patient with large breasts (a) and a patient with small breasts (b) and the corresponding wire defined 50% and 95% isodoses (c and d)
Fig. 2
Fig. 2
Glandular proportion within the clinical target volume (CTV) contoured according to ESTRO guidelines (eCTV)
Fig. 3
Fig. 3
Dice conformity index (DC)
See this image and copyright information in PMC

References

    1. Sedlmayer F, et al. DEGRO practical guidelines: radiotherapy of breast cancer I: radiotherapy following breast conserving therapy for invasive breast cancer. Strahlenther Onkol. 2013;189(10):825–833. doi: 10.1007/s00066-013-0437-8. - DOI - PMC - PubMed
    1. Offersen BV, et al. ESTRO consensus guideline on target volume delineation for elective radiation therapy of early stage breast cancer, version 1.1. Radiother Oncol. 2016;118(1):205–208. doi: 10.1016/j.radonc.2015.12.027. - DOI - PubMed
    1. Offersen BV, et al. ESTRO consensus guideline on target volume delineation for elective radiation therapy of early stage breast cancer. Radiother Oncol. 2015;114(1):3–10. doi: 10.1016/j.radonc.2014.11.030. - DOI - PubMed
    1. Early Breast Cancer Trialists’ Collaborative Group Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10,801 women in 17 randomised trials. Lancet. 2011;378(9804):1707–1716. doi: 10.1016/S0140-6736(11)61629-2. - DOI - PMC - PubMed
    1. Venables K, et al. Does participation in clinical trials influence the implementation of new techniques? A look at changing techniques in breast radiotherapy in the UK. Clin Oncol (R Coll Radiol) 2012;24(8):e100–e105. doi: 10.1016/j.clon.2012.06.010. - DOI - PubMed

LinkOut - more resources