Intraoperative Radiotherapy with electrons

Intraoperative radiotherapy (IORT) with electrons allow to apply a high single dose to a locally restricted volume, which could be clearly defined during surgical procedure. Especially in cases with relative dose limitation using external beam radiotherapy (EBRT) only due to normal structures the IORT technique is meaningful. Many retrospective or non-randomized data support the use of IORT but prospective randomized data are mostly not available. Intraoperative electron radiotherapy (IOERT) seems to be a valide option for patients with locally very advanced or recurrent rectal cancer. In retroperitoneal sarcomas the advantages of IORT are clearly recognizable shown in a randomized-trial. The IOERT patients had a significantly lower local-regional relapse rate. Concerning breast cancer treatment the favorable efficacy of an IOERT-boost compared to an EBRT-boost could be shown in a sequential intervention study. Also, in a European pooled data analysis including 1,031 patients highly encouraging results after IOERT were published. An open question is the value of the sole PBI in breast cancer patients in the context of breast conservation. The prospective and randomized ELIOT-trial addressing this question show higher local recurrences in the IORT only group and led to the study group’s statement that IOERT as partial breast irradiation (PBI) should be restricted to suitable patients, once characteristics defining suitability have been defined.