Frequency of whole breast irradiation (WBRT) after intraoperative radiotherapy (IORT) is strongly influenced by institutional protocol qualification criteria

Abstract

Background

Accelerated partial breast irradiation (APBI) is a promising method of adjuvant radiotherapy for select patients. Intraoperative radiotherapy (IORT) is a form of APBI, and appropriate patient selection is important.

Aim

The aim of our study was to analyse the influence of our protocol on the frequency of WBRT after IORT and our protocol's correlation with the reported use of WBRT according to TARGIT guidelines. We also aimed to verify how changes in our protocol influenced the frequency of WBRT.

Material and methods

Between April 20, 2010 and May 10, 2017, we identified 207 patients irradiated with IORT for APBI.

Results

Ninety-one patients (44%) met the criteria for APBI only, while 116 (56%) should have been offered additional WBRT. Retrospective analysis showed that WBRT was applied statistically significantly less frequently compared with strict protocol indications: 99 patients (47.8%) received APBI only and 108 (51.2%) underwent adjuvant WBRT (p[[ce:hsp sp="0.25"/]]<[[ce:hsp sp="0.25"/]]0.0001). Applying the TARGIT trial guidelines, 69 patients (33.4%) should have been offered WBRT (p[[ce:hsp sp="0.25"/]]<[[ce:hsp sp="0.25"/]]0.0001), which is twice the number of patients treated with WBRT in our study. Changing the protocol to less restrictive criteria would have statistically significantly decreased the number of patients (95, 46%) offered WBRT (p[[ce:hsp sp="0.25"/]]<[[ce:hsp sp="0.25"/]]0.0001).

Conclusions

Following international guidelines, 46% of patients should receive WBRT after IORT, which is 1.5–2 times more than for the TARGIT criteria. In our analysis, a high percentage of patients (19%) did not receive WBRT after IORT despite the protocol recommendations. The chosen protocol strongly influences the frequency of adjuvant WBRT.