Reducing the risk of radiation-induced cardiotoxicity in patients with left breast tumor.

Zsófia Dankovics, Tamás Ungvári, Döme Szabó, András Heim, Béla Farkas, Balázs Kiss, András Csejtei, Judit Olajos

Breast cancer is one of the most common malignancies affecting women. Treatment with drugs and radiotherapy increases the incidence of late cardiovascular disease. It is therefore particularly important to protect the heart from radiation exposure. We prepared an irradiation plan for 45 patients with left breast cancer using deep breathing and normal breathing techniques. The plans were compared and analyzed. The irradiation plans were created in the Philips Pinnacle v. 16 planning system. At the same target volume coverage, the use of the deep breathing technique leads to a reduction of the dose burden to the heart and to the left descending coronary branch, thus reducing the incidence of late cardiovascular complications. The results obtained show that the use of the deep breathing technique during adjuvant radiotherapy of left-sided breast cancer patients has a beneficial effect on the radiation exposure of the heart. Our results are in good agreement with similar data from national centres. We were not only able to maintain planning target volume coverage, but also to achieve an improvement of 1%. There is a significant difference in dose to the heart and coronary artery. By using the deep breathing technique, we were able to reduce the average cardiac dose by almost half (deep breathing: 2.87 Gy, normal breathing: 5.4 Gy). The coronary exposure was reduced from 19.5 Gy to 10.98 Gy. The accuracy of treatment can be further improved by using a respiratory gating system with a surface-guided radiotherapy system. The successful use of deep breathing technique requires professionalism of the treatment staff and good patient cooperation. It is less equipment intensive than a respiration-guided system. The deep breathing technique is no longer considered state-of-the-art in the era of breath-holding, but the experience gained in our department is worth describing because of its relevance to oncocardiology. Orv Hetil. 2023; 164(11): 420-425.