Aim of the study. The aim of the study was a retrospective evaluation of the potential reduction of the risk of myocardial complications after radiotherapy. This was based on ECG records of women with breast cancer after breast conserving surgery who underwent conformal 3D-planned radiotherapy compared to a group of women who underwent 2D-planned irradiation. Another goal was evaluation of possible diff erences in the rate of myocardial complications between the patients with lesions in the left or right breast when using the modern techniques of radiotherapy.

Material and methods. Between April 1985 and December 2008, 1211 patients who had breast conserving surgery underwent radiotherapy in the 1st Department of Radiotherapy of The Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology in Warsaw. We analyzed the group of 595 women who had follow-up examinations with ECG after the treatment. Their age range was 27–78 years. 327 had left and 268 right breast cancer. All had irradiation of the whole breast and additionally of the post-operative site after removal of the tumor according to the protocol accepted in the Institute of Oncology. 382 patients underwent radical 2D-planned radiotherapy and 213 conformal 3D-planned radiotherapy.

Results: Evaluation of ECG results revealed that alterations (non-specifi c or ischemic) occurred in 32.7% of the patients with the cancer of the left breast and in 29.1% of those with right breast cancer. In patients who received radical 2D treatment ECG alterations occurred in 34.1% of those with left breast cancer compared to 29.9% with those with right breast cancer. In patients who received 3D conformal radiotherapy ECG alterations were observed in 30.3% with left breast cancer and in 27.5% with right breast cancer. There were no statistically signifi cant diff erences depending on the localization of the lesion and the technique of irradiation in the rates of myocardial complications evaluated using by ECG records.

Conclusions. The change from radical 2D to 3D conformal technique of radiotherapy does not result in the reduction of myocardial complications evaluated using ECG records. Also, there is no signifi cant diff erence in complication rates with tumour localization.