Abstract 186P
Background
Early breast cancer patients with complex anatomy received adjuvant intensity modulated radiotherapy with helical tomotherapy (IMRT-HT) in our Institut. The aim was to evaluate our experience in terms of local control, overall survival, progression free survival and adverse events.
Methods
This study is a retrospective data analysis, of patients treated with helical tomotherapy irradiation technique. Overall survival (OS) and progression free survival (PFS) curves were plotted with Kaplan-Meier method. We also analyzed the OS and PFS data by molecular subgroups. Long term toxicities were evaluated using Common Terminology Criteria of Adverse Events (CTCAE) version 4.0. Multivariant analysis was performed to determine the predictors of the toxicities.
Results
Between 2009 and 2015, 174 patients with 194 treated breasts were irradiated with helical tomotherapy. The median follow-up were 65 months. The 8-year OS was 89,2 % (IC95: 83.5% - 95.4 %), the 8-year PFS was 85,4% (IC95: 80.2%- 91%). The longest 5 year OS data was in the HER2 receptor positive subroup 95% (IC95: 85.9% - 100%). Long term skin toxicity was the most common long term side effect, seen by 20.7% of the patients. 5 patients had second primer breast cancer, always located at the contralateral breast. In multivariant analysis BMI>25 kg/m2 was found to be a predictor of elevated skin toxicity, and pre-existing cardiovascular history could significantly elevate the risk of cardiovascular toxicity.
Conclusions
HT could be safely used for adjuvant breast cancer irradiation. In patients with complex anatomy HT improves clinical target volume coverage and spare the dose to OARs. Further prospective studies with long follow-up are needed to confirm and validate these results.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Institut Curie.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.