Available online at www.sciencedirect.com
ScienceDirect EJSO xx (2014) 1e3
www.ejso.com
Editorial
Is current evidence about intraoperative partial breast irradiation sufficient for broad implementation in clinical practice? As a result of earlier diagnosis, improved imaging and histopathological evaluation, and the progress in locoregional and systemic treatment of breast cancer, the outcome of breast cancer patients continues to improve including a remarkable reduction in the rate of local recurrences after breast conserving therapy (BCT).1 Because of the possible side effects related to both locoregional and systemic treatments, research towards lowering the treatment burden, especially in low risk breast cancer patients, has being conducted. This was very successful especially for the surgical component of breast cancer management (BCT; diagnostic sentinel lymph node (SLN) biopsy); at this moment it remains controversial for the regional component of the treatment (especially for lymph node irradiation, further axillary surgery in the case of involvement of the SLN and for the management after primary systemic therapy), and it is challenged in the field of adjuvant systemic therapy. One of the approaches towards lowering the local burden of treatment is accelerated partial breast irradiation (APBI), in which radiation therapy is limited to the breast tissue surrounding the primary tumour bed after lumpectomy. This concept evolved since it was demonstrated that 80% of ipsilateral breast recurrences occur at the primary tumour bed. Several technical approaches of partial breast irradiation have been developed which can be separated into intraoperative and postoperative irradiation as well as into invasive and non-invasive. These include interstitial and balloon-based brachytherapy, intraoperative radiation therapy (IORT), and external beam APBI. The contribution by the surgical oncologist is always important from the point of view of patient selection and defining the target volume and is essential for the intraoperative procedures as they require special training and the availability of dedicated equipment and infrastructure in and around the operating room. Each of the techniques, when applied by an experienced team, might be safely administered but data to compare them with each other for efficiency as well as toxicity are to be awaited for.
ASTRO and GEC-ESTRO formulated a consensus definition to classify patients into 3 risk groups towards the option of APBI, although both stated that this should preferably be offered in the framework of a clinical trial.2,3 This careful recommendation was probably supported by the different technical approaches used in the available publications, with a remarkable variation in dose, treated volume, ability to cover the clinical target volume and possible radiobiological differences.4 Most importantly, long-term results are lacking, with the exception of the small Budapest trial (only 88 patients treated with an interstitial APBI technique) and the ELIOT trial.5,6 Finally, a number of reports described a higher complication rate including a higher risk for a poor cosmesis after APBI.7,8 In the ELIOT trial,6 a selected group of patients was randomised to standard whole breast irradiation (WBI) or a single dose IORT electron beam technique. After a median follow-up of 5.8 years, ipsilateral breast recurrence rate was significantly higher in the IORT group (4.4% versus 0.4%, P < 0.0001), a difference that further increased over time to 8.4% at 8 years and 11.2% at 10 years. At the same time, 1822 selected patients were treated outside of the randomised ELIOT trial. In the favourable subgroups as defined by GEC-ESTRO and ASTRO, results were very favourable with an annual recurrence rate of
ScienceDirect EJSO xx (2014) 1e3
www.ejso.com
Editorial
Is current evidence about intraoperative partial breast irradiation sufficient for broad implementation in clinical practice? As a result of earlier diagnosis, improved imaging and histopathological evaluation, and the progress in locoregional and systemic treatment of breast cancer, the outcome of breast cancer patients continues to improve including a remarkable reduction in the rate of local recurrences after breast conserving therapy (BCT).1 Because of the possible side effects related to both locoregional and systemic treatments, research towards lowering the treatment burden, especially in low risk breast cancer patients, has being conducted. This was very successful especially for the surgical component of breast cancer management (BCT; diagnostic sentinel lymph node (SLN) biopsy); at this moment it remains controversial for the regional component of the treatment (especially for lymph node irradiation, further axillary surgery in the case of involvement of the SLN and for the management after primary systemic therapy), and it is challenged in the field of adjuvant systemic therapy. One of the approaches towards lowering the local burden of treatment is accelerated partial breast irradiation (APBI), in which radiation therapy is limited to the breast tissue surrounding the primary tumour bed after lumpectomy. This concept evolved since it was demonstrated that 80% of ipsilateral breast recurrences occur at the primary tumour bed. Several technical approaches of partial breast irradiation have been developed which can be separated into intraoperative and postoperative irradiation as well as into invasive and non-invasive. These include interstitial and balloon-based brachytherapy, intraoperative radiation therapy (IORT), and external beam APBI. The contribution by the surgical oncologist is always important from the point of view of patient selection and defining the target volume and is essential for the intraoperative procedures as they require special training and the availability of dedicated equipment and infrastructure in and around the operating room. Each of the techniques, when applied by an experienced team, might be safely administered but data to compare them with each other for efficiency as well as toxicity are to be awaited for.
ASTRO and GEC-ESTRO formulated a consensus definition to classify patients into 3 risk groups towards the option of APBI, although both stated that this should preferably be offered in the framework of a clinical trial.2,3 This careful recommendation was probably supported by the different technical approaches used in the available publications, with a remarkable variation in dose, treated volume, ability to cover the clinical target volume and possible radiobiological differences.4 Most importantly, long-term results are lacking, with the exception of the small Budapest trial (only 88 patients treated with an interstitial APBI technique) and the ELIOT trial.5,6 Finally, a number of reports described a higher complication rate including a higher risk for a poor cosmesis after APBI.7,8 In the ELIOT trial,6 a selected group of patients was randomised to standard whole breast irradiation (WBI) or a single dose IORT electron beam technique. After a median follow-up of 5.8 years, ipsilateral breast recurrence rate was significantly higher in the IORT group (4.4% versus 0.4%, P < 0.0001), a difference that further increased over time to 8.4% at 8 years and 11.2% at 10 years. At the same time, 1822 selected patients were treated outside of the randomised ELIOT trial. In the favourable subgroups as defined by GEC-ESTRO and ASTRO, results were very favourable with an annual recurrence rate of
