Should breathing adapted radiotherapy also be applied for right-sided breast irradiation?

Abstract

Background: Voluntary moderate deep inspiration breath-hold (vmDIBH) is widely used for left sided breast cancer patients. The purpose of this study was to investigate the usefulness of vmDIBH in local and locoregional radiation therapy (RT) of right-sided breast cancer. Materials and Methods: For fourteen right-sided breast cancer patients, 3D-conformal (3D-CRT) RT plans (i.e., forward IMRT) were calculated on free-breathing (FB) 3D-CRT(FB) and vmDIBHCT-scans, for local-as well as locoregional breast treatment, with and without internal mammary nodes (IMN). Dose volume parameters were compared. Results: For local breast treatment, no relevant reduction in mean lung dose (MLD) was found. For locoregional breast treatment without IMN, the average MLD reduced from 6.5 to 5.4 Gy (p50.005) for the total lung and from 11.2 to 9.7 Gy (p50.005) for the ipsilateral lung. For locoregional breast treatment with IMN, the average MLD reduced from 10.8 to 9.1 Gy (p50.005) for the total lung and from 18.7 to 16.2 Gy (p50.005) for the ipsilateral lung, whilea small reduction in mean heart dose of 0.4 Gy (p ¼ 0.07) was also found. Conclusions: Breathing adapted radiation therapy in left-sided breast cancer patients is becoming widely introduced. As a result of the slight reduction in lung dose found for locoregional rightsided breast cancer treatment in this study, a slightly lower risk of pneumonitis and secondary lung cancer (in ever smoking patients) can be expected.In addition, for some patients the heart dose will also be reduced by more than 0.5 up to 2.6 Gy. We therefore suggest to also apply breath-hold for locoregional irradiation of right-sided breast cancer patients.

The potential benefits from respiratory gating for breast cancer patients regarding target coverage and dose to organs at risk when applying strict dose limits to the heart: results from the DBCG HYPO trial

“…The findings between FB right-sided and FB left-sided versus RG left-sided treatments were identical in the two arms as expected. For rightsided treatment plans Essers et al reported no gain from RG for breast only RT considering dose to OAR [24]. This supports the usefulness of considering FB right-sided treatment plans as the control group.…”

Liver dose reduction by deep inspiration breath hold technique in right-sided breast irradiation

“…The primary aim of our study was to assess the dosimetric benefits of DIBH compared to standard free breathing (FB) approaches in terms of liver doses for RBC patients following mastectomy. Previous studies exclusively focused on patients with LBC, and just two recent studies have examined the benefit and applicability of DIBH in patients with RBC [9,10]. Although these studies provide evidence in this field, they are not without shortcomings.…”

“…Although these studies provide evidence in this field, they are not without shortcomings. Firstly, liver doses were not addressed by Essers et al [9] in the first study. Another study that provided dosimetric comparison of liver doses between the techniques was conducted on LBC patients, as intact right breast was assumed to be representative of breast-conserving surgery for dosimetry purposes [10].…”

“…Another study that provided dosimetric comparison of liver doses between the techniques was conducted on LBC patients, as intact right breast was assumed to be representative of breast-conserving surgery for dosimetry purposes [10]. On the other hand, both studies [9,10] followed the European Society for Radiotherapy and Oncology (ESTRO) breast and nodal contouring guidelines, involving larger lung volumes in the treatment field than standard clinical practice [11]. We preferred to use the Radiation Therapy Oncology Group (RTOG) contouring guidelines, which are more widely used in clinical practice [12].…”

The volume of liver irradiated during modern free-breathing breast radiotherapy: Implications for theory and practice

“…10 Leveraging the inherent stability of DIBH can reduce cranio-caudal intrafraction hepatic motion from 19mm to 1-5mm, 25,26 reduce liver volume by 63% (134cm 3 to 50cm 3 ) and mean liver dose by 46% (from 4.8 to 2.6 Gy) compared to a free breathing plan 10 and deliver superior ipsilateral and total lung dosimetry. 27,28 The range of maximum liver dose in the current study was surprisingly large for left-sided treatments. Median data confirmed the phenomena of liver irradiation was negligible for all but one participant, who had a medially-placed tumour, a high BMI and SCF irradiation that exaggerated inferior beam divergence for tangential fields.…”