Phase III randomised trialDoes an integrated boost increase acute toxicity in prone hypofractionated breast irradiation? A randomized controlled trial
Section snippets
Patients
As illustrated in the Consort diagram (Fig. 1), 168 patients were included after breast conserving surgery for early-stage breast carcinoma. 151 patients were treated at Ghent University Hospital (UZ Gent) and 17 at Liège University Hospital (CHU Liège). The study was approved by the Ethics Board of both hospitals and registered at clinicaltrials.gov (NCT01973634). Exclusion criteria were: mastectomy, lymph node irradiation, no boost dose planned according to the institution’s practice
Results
Patient and treatment characteristics of the 167 analysed patients are shown in Table 1. Patients in the control arm were slightly older (mean age 59.5 years versus 55.7 years in the experimental arm, p = 0.028). The other variables were not significantly different between treatment arms.
The analysis of dose parameters was done on 163 patients (80 patients in the control arm and 83 patients in the SIB arm). Reasons for excluding patients were electron boost (2), 3 different plans on 3 different CTs
Discussion
Strong evidence now exists that breast cancer cells are as sensitive to fraction size as healthy tissues [25], justifying the use of hypofractionation schemes lowering the total dose but increasing the dose per fraction. WBI in 15–16 fractions is standard practice in the United Kingdom for several years now. After publication of the 10 year results of the UK and Canadian randomized trials, showing excellent efficacy and less long-term side effects of these schemes compared to more protracted
Conclusion
No difference was observed between treatment arms in the rate of moist desquamation, the primary endpoint of the trial. A SIB in combination with prone hypofractionated WBI appears to be a safe treatment regarding acute toxicity, but long-term data have to be awaited.
Conflict of interest statement
The authors report no conflict of interest.
Acknowledgements
This work was financed through Cancer Plan Action 29 (project 015 and 008) by the Federal Public Service of Health, Food Chain Safety and Environment, Belgium. Liv Veldeman is funded by a grant of Kom op tegen Kanker (Clinical Mandate). Christel Monten and Tom Vercauteren are recipients of a grant from the Clinical Research Fund of Ghent University Hospital. Special thanks to Karolien Roelants who was responsible for the artwork.
References (32)
- et al.
The UK Standardisation of Breast Radiotherapy (START) trials of radiotherapy hypofractionation for treatment of early breast cancer: 10-year follow-up results of two randomised controlled trials
Lancet Oncol
(2013) - et al.
Whole-breast irradiation with or without a boost for patients treated with breast-conserving surgery for early breast cancer: 20-year follow-up of a randomised phase 3 trial
Lancet Oncol
(2015) - et al.
Simultaneous-integrated boost intensity-modulated radiation therapy (SIB-IMRT) in the treatment of early-stage left-sided breast carcinoma
Med Dosim
(2006) - et al.
Simultaneous integrated boost for breast cancer using IMRT: a radiobiological and treatment planning study
Int J Radiat Oncol Biol Phys
(2004) - et al.
The influence of simultaneous integrated boost, hypofractionation and oncoplastic surgery on cosmetic outcome and PROMs after breast conserving therapy
Eur J Surg Oncol
(2015) - et al.
Prospective randomized trial of prone accelerated intensity modulated breast radiation therapy with a daily versus weekly boost to the tumor bed
Int J Radiat Oncol Biol Phys
(2016) - et al.
Five year outcomes of hypofractionated simultaneous integrated boost irradiation in breast conserving therapy; patterns of recurrence
Radiother Oncol
(2013) - et al.
Prone breast intensity modulated radiation therapy: 5-year results
Int J Radiat Oncol Biol Phys
(2014) - et al.
Prone versus supine positioning for whole and partial-breast radiotherapy: a comparison of non-target tissue dosimetry
Radiother Oncol
(2010) - et al.
Prospective assessment of optimal individual position (prone versus supine) for breast radiotherapy: volumetric and dosimetric correlations in 100 patients
Int J Radiat Oncol Biol Phys
(2012)