Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Aug 28, 2016; 8(8): 735-742
Published online Aug 28, 2016. doi: 10.4329/wjr.v8.i8.735
Helical tomotherapy and volumetric modulated arc therapy: New therapeutic arms in the breast cancer radiotherapy
Olivier Lauche, Youlia M Kirova, Pascal Fenoglietto, Emilie Costa, Claire Lemanski, Celine Bourgier, Olivier Riou, David Tiberi, Francois Campana, Alain Fourquet, David Azria
Olivier Lauche, Youlia M Kirova, Emilie Costa, Francois Campana, Alain Fourquet, Department of Radiation Oncology, Institut Curie, 75005 Paris, France
Pascal Fenoglietto, Claire Lemanski, Celine Bourgier, Olivier Riou, David Azria, Departement of Radiation Oncology, Institut du Cancer de Montpellier, 34298 Montpellier cedex 5, France
David Tiberi, Department of Radiation Oncology, Centre Hospitalier de l’Université de Montréal Hôpital Notre Dame, Montreal H2L 4M1, Canada
Author contributions: Lauche O and Kirova YM participated in the conception, acquisition, analysis, interpretation of the data and drafted the initial manuscript; Kirova YM and Azria D were the guarantor and designed the study; Fenoglietto P participated in the analysis and the interpretation of the data; Costa E, Lemanski C, Bourgier C, Riou O and Fourquet A revised the article critically for important intellectual content; Language revision was realized by Tiberi D from Canada (native speaker); Campana F participated in the treatment of the patients and revised the article.
Institutional review board statement: The study was reviewed and approved by the Breast Cancer Groups of Curie Institute and Montpellier Cancer Institute.
Informed consent statement: Not applicable given the retrospective design of our study.
Conflict-of-interest statement: There are no conflicts of interest to report.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Youlia M Kirova, MD, Chief of breast cancer research and treatment in the Department of Radiation Oncology, Institut Curie, 26, rue d’Ulm, 75005 Paris, France. youlia.kirova@curie.fr
Telephone: +33-1-44324193 Fax: +33-1-44324616
Received: February 23, 2016
Peer-review started: February 25, 2016
First decision: April 15, 2016
Revised: May 12, 2016
Accepted: June 27, 2016
Article in press: June 29, 2016
Published online: August 28, 2016
Processing time: 184 Days and 18.2 Hours
Abstract
AIM

To analyse clinical and dosimetric results of helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) in complex adjuvant breast and nodes irradiation.

METHODS

Seventy-three patients were included (31 HT and 42 VMAT). Dose were 63.8 Gy (HT) and 63.2 Gy (VMAT) in the tumour bed, 52.2 Gy in the breast, 50.4 Gy in supraclavicular nodes (SCN) and internal mammary chain (IMC) with HT and 52.2 Gy and 49.3 Gy in IMC and SCN with VMAT in 29 fractions. Margins to particle tracking velocimetry were greater in the VMAT cohort (7 mm vs 5 mm).

RESULTS

For the HT cohort, the coverage of clinical target volumes was as follows: Tumour bed: 99.4% ± 2.4%; breast: 98.4% ± 4.3%; SCN: 99.5% ± 1.2%; IMC: 96.5% ± 13.9%. For the VMAT cohort, the coverage was as follows: Tumour bed: 99.7% ± 0.5%, breast: 99.3% ± 0.7%; SCN: 99.6% ± 1.4%; IMC: 99.3% ± 3%. For ipsilateral lung, Dmean and V20 were 13.6 ± 1.2 Gy, 21.1% ± 5% (HT) and 13.6 ± 1.4 Gy, 20.1% ± 3.2% (VMAT). Dmean and V30 of the heart were 7.4 ± 1.4 Gy, 1% ± 1% (HT) and 10.3 ± 4.2 Gy, 2.5% ± 3.9% (VMAT). For controlateral breast Dmean was 3.6 ± 0.2 Gy (HT) and 4.6 ± 0.9 Gy (VMAT). Acute skin toxicity grade 3 was 5% in the two cohorts.

CONCLUSION

HT and VMAT in complex adjuvant breast irradiation allow a good coverage of target volumes with an acceptable acute tolerance. A longer follow-up is needed to assess the impact of low doses to healthy tissues.

Keywords: Three-dimensional conformal radiotherapy; Intensity modulated radiation therapy; Toxicity; Helical tomotherapy; Volumetric modulated arc therapy; Breast cancer radiotherapy

Core tip: Using conventional techniques in breast and nodes irradiation, there could be suboptimal target coverage or great dose exposure to the normal structures. Our study suggests that helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) plans provide excellent target volume coverage and reduces high doses to organs at risk with an acceptable acute toxicity. At the same time, HT and VMAT deliver lower doses to larger volumes of normal tissues, suggesting in some cases an increased risk of second cancer. Nevertheless, the risk to benefit ratio seems to be in favour of HT and VMAT as opposed to three-dimensional conformal radiation therapy in complex target volumes, such as funnel chest, tumor in the inner quadrant when internal mammary chain and tumor bed boost are indicated, large breast size or unfavourable cardiac anatomy.