IMPACT OF RESPIRATORY GATING ON DOSE DISTRIBUTION AND PROTECTION OF CRITICAL ORGANS IN RADIOTHERAPY FOR BREAST CANCER

This study is dedicated to the dosimetric evaluation of the Deep Inspiration Breath Hold (DIBH) technique as a cardioprotective method during adjuvant radiotherapy for left-sided breast cancer. The primary objective of the research was to compare the dosimetric parameters of radiation exposure to the heart in the DIBH mode with those obtained in the conventional Free Breathing (FB) mode, while maintaining adequate coverage of the Planning Target Volume (PTV). To achieve this objective, a retrospective dosimetric analysis of three-dimensional conformal radiotherapy (3D-CRT) plans for 10 patients was performed. Key dose–volume metrics for the PTV, lungs, heart, esophagus, spinal cord, and contralateral breast were assessed. The results demonstrated that, despite the dosimetric equivalence in PTV coverage and protection of lung parenchyma (V20 Gy), the DIBH technique provides a pronounced protective effect on cardiac structures. In the DIBH mode, a statistically significant reduction of more than 50% in the mean heart dose (Dmean) was observed – from 33,16±3,79 Gy to 15,49±4,50 Gy (p  0,001). The most substantial reduction in radiation exposure was recorded for the left anterior descending coronary artery (LAD). This sparing effect is explained by the physiological caudal displacement of the heart during deep inspiration, effectively increasing the distance between the heart and the irradiation field. Thus, the DIBH technique ensures excellent cardioprotection, significantly reducing long-term cardiovascular risks – particularly those associated with LAD exposure – without compromising the oncological adequacy of treatment. These findings confirm the necessity of implementing DIBH as a gold standard in regional clinical radiotherapy protocols.

1. De la Cruz Ku G., Karamchandani M., Chambergo-Michilot D. [et al.] Dose breast-conserving surgery with radiotherapy have a better survival than mastectomy? A meta-analysis of more than 1,500,000 patients // Ann. Surg. Oncol. – 2022. – Vol. 29, No. 10. – P. 6163–6188. – https://doi.org/10.1245/s10434-022-12133-8

2. Khan L., Khan M., Shakeel F., Ali T., Hina M. [et al.] Effect of DIBH Coaching on Dosimetric Parameters of Heart and Lung Doses in Patients Undergoing Adjuvant Breast Radiotherapy // Asian Pac. J. Cancer Prev. – 2025. – Vol. 26, No. 5. – P. 1809–1813. – https://doi.org/10.31557/APJCP.2025.26.5.1809

3. Semiz V., Aydin B., Gulsan D., Atac E., Ozkaya E. [et al.] Comprehensive analysis of the role of deep inspiration breath-hold in right-sided breast cancer radiotherapy: A focus on cardiac substructures and right coronary artery // J. Appl. Clin. Med. Phys. – 2025. – Vol. 26, No. 9. – Art. e70216. – https://doi.org/10.1002/acm2.70216

4. Gradishar W.J., Moran M.S., Abraham J. [et al.] NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) // Breast Cancer. – Version 4.2024. URL: https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1419.

5. Schönecker S., Angelini L., Gaasch A., Zinn A., Konnerth D. [et al.] Surface-based deep inspiration breath-hold radiotherapy in left-sided breast cancer: final results from the SAVE-HEART study // ESMO Open. – 2024. – Vol. 9(12). – Art. 103993. – https://doi.org/10.1016/j.esmoop.2024.103993

6. Zhuang Y., Wu Y., Wang H. [et al.] Survival outcomes after breast‑conserving surgery plus radiotherapy compared with mastectomy for early breast cancer: population‑based study // Cancers. – 2025. – Vol. 15, No. 24. – Art. 5799. – https://doi.org/10.3390/cancers15245799

7. Becker K., Kisling K., Padilla L. Clinical factors affecting breath-hold performance for left-sided breast cancer patients // J. Appl. Clin. Med. Phys. – 2025. – Vol. 12. – Art. e70364. – https://doi.org/10.1002/acm2.70364

8. Arslan A., Aktas E., Sengul B., Tekin B. Dosimetric evaluation of left ventricle and left anterior descending artery in left breast radiotherapy // Radiol. Med. – 2021. – Vol. 126(1). – P. 14–21. – https://doi.org/10.1007/s11547-020-01201-2

9. Loap P., Tkatchenko N., Goudjil F., Ribeiro M., Baron B., Fourquet A., Kirova Y. Cardiac substructure exposure in breast radiotherapy: a comparison between intensity modulated proton therapy and volumetric modulated arc therapy // Acta Oncol. – 2021. – Vol. 60(8) – P. 1038– 1044. – https://doi.org/10.1080/0284186X.2021.1907860

10. Doležel M., Odrážka K., Vaňásek J. Deep-inspiration breath hold radiotherapy in patients with left-sided breast cancer after partial mastectomy // Rozhl Chir. – 2021. – Vol. 100(4) – P. 180–185. – https://doi.org/10.33699/PIS.2021.100.4

11. Chau O.W., Fakir H., Lock M., Dinniwell R., Perera F., Erickson A., Gaede S. Dosimetric Planning Comparison for Left-Sided Breast Cancer Radiotherapy: The Clinical Feasibility of Four-Dimensional-Computed Tomography-Based Treatment Planning Optimization // Cureus. – 2022. – Vol. 6 – 14(5). – Art. e24777. – https://doi.org/10.7759/cureus.24777

12. Ferini G., Valenti V., Viola A., Umana G.E., Martorana E. A Critical Overview of Predictors of Heart Sparing by Deep-Inspiration-Breath-Hold Irradiation in Left-Sided Breast Cancer Patients // Cancers (Basel). – 2022. – Vol. 18 – 14(14). – Art. 3477. – https://doi.org/10.3390/cancers14143477

13. Desai N., Currey A., Kelly T., Bergom C. Nationwide Trends in Heart-Sparing Techniques Utilized in Radiation Therapy for Breast Cancer // Adv. Radiat. Oncol. – 2019. – Vol. 30 – 4(2). – P. 246–252. – https://doi.org/10.1016/j.adro.2019.01.001

14. Wolf J., Stoller S., Lübke J., Rothe T., Serpa M., Scholber J., Zamboglou C., Gkika E., Baltas D., Juhasz-Böss I., Verma V., Krug D., Grosu A.L., Nicolay N.H., Sprave T. Deep inspiration breath-hold radiation therapy in left-sided breast cancer patients: a single-institution retrospective dosimetric analysis of organs at risk doses // Strahlenther Onkol. – 2023. – Vol. 199(4) – P. 379–388. – https://doi.org/10.1007/s00066-022-01998-z

15. Mahmoud A.A., Sadaka E.A., Abouegylah M., Amin S.A., Elmansy H., Asal M.F., Köksal M.A., Gawish A. Impact of breath-hold technique on incidence of cardiac events in adjuvant left breast cancer irradiation // J. Cancer. Res. Clin. Oncol. – 2023. – Vol. 149(9) – P. 5853–5859. – https://doi.org/10.1007/s00432-022-04551-8

16. Nair S., Devi V.N.M., Sharan K., Nagesh J., Nallapati B., Kotian S. A Dosimetric Study Comparing Different Radiotherapy Planning Techniques With and Without Deep Inspiratory Breath Hold for Breast Cancer // Cancer Manag. Res. – 2022. – Vol. 29 –14. – P. 3581–3587. – https://doi.org/10.2147/CMAR.S381316

17. Vander Veken L., Van Ooteghem G., Razavi A., Da Rita Quaresma S. [et al.] Voluntary versus mechanically-induced deep inspiration breath-hold for left breast cancer: A randomized controlled trial // Radiother. Oncol. – 2023. – Vol. 183. – Art. 109598. – https://doi.org/10.1016/j.radonc.2023.109598

18. Hussein S.H., Kassem L., Adrosy M.I., Metwally H. Comparison Between Breath-Hold and the Inspiratory Phase of Free Breathing in Left Breast Cancer Radiotherapy: Target Volume Coverage and Organ Sparing // Asian Pac. J. Cancer Prev. – 2025. – Vol. 26(3) – P. 969– 975. – https://doi.org/10.31557/APJCP.2025.26.3.969

19. Busschaert S L., Kimpe E., Barbé K., Gevaert T., De Ridder M., Putman K. Deep inspiration breath-hold for breast cancer radiotherapy: a modelling study of targeted versus non-targeted strategy for clinical and operational optimisation. // Lancet Reg. Health Eur. – 2025. – Vol. 1. – Iss. 60. – Art. 101509. – https://doi.org/10.1016/j.lanepe.2025.101509

20. Jiang S., Shi H., Ye X., Yang J., Zheng J., Wu P., Ye Q., Qin S., Liu W., Hu Z., Cai Y. A three-day coaching protocol for deep inspiration breath hold in left breast radiotherapy using active breathing control // Sci. Rep. – 2025. – Vol. 4 –15(1). – Art. 43661. – https://doi.org/10.1038/s41598-025-30484-6

21. Moisander M., Tuohinen S., Lahdeaho H., Huhtala H. [et al.] The evolution of cardiac changes after breast cancer adjuvant radiotherapy – A six-year follow-up study // Clin. Transl. Radiat. Oncol. – 2025. – Vol. 56. – Art. 101078. – https://doi.org/10.1016/j.ctro.2025.101078

22. Schonecker S., Angelini L., Gaasch A., Zinn A., Konnerth D., Heinz C. [et al.] Surface-based deep inspiration breath-hold radiotherapy in left-sided breast cancer: final results from the SAVE-HEART study // ESMO Open. – 2024. – Vol. 9(12). – Art. 103993. – https://doi.org/10.1016/j.esmoop.2024.103993

23. Falco M., Masojc B., Macała A., Lukowiak M., Wozniak P., Malicki J. Deep inspiration breath hold reduces the mean heart dose in left breast cancer radiotherapy // Radiol. Oncol. – 2021. – Vol. 55(2). – P. 212–220. – https://doi.org/10.2478/raon-2021-0008

24. Gaal S., Kahan Z., Rarosi F., Fodor H. G., Tolnai J. Individual benefit in heart sparing during DIBH-supported left breast radiotherapy. // Clinical and Translational Radiation Oncology. – 2024. – Vol. 46 – Art. 100746. – https://doi.org/10.1016/j.ctro.2024.100746

25. J. Lai, S. Hu, Y. Luo, R. Zheng, Q. Zhu, P. Chen [et al.] Meta-analysis of deep inspiration breath hold (DIBH) versus free breathing (FB) in postoperative radiotherapy for left-side breast cancer // Breast Cancer. – 2020. – Vol. 27 – P. 299–307. – https://doi.org/10.1007/s12282-019-01023-9

26. Aldaly M., Hussien A., El-Nadi I.M., Laz N.I., Said A.S.A. [et al.] Comparison of 3D Conformal and Deep Inspiratory Breath Holding vs. 4D-CT Intensity-Modulated Radiation Therapy for Patients with Left Breast Cancer // Cancers (Basel). – 2023. – Vol. 15(24). – Art. 5799. – https://doi.org/10.3390/cancers15245799

27. Taylor C.W., Wang Z., Macaulay E., Jagsi R., Duane F., Darby S.C. Exposure of the Heart in Breast Cancer Radiation Therapy: A Systematic Review of Heart Doses Published During 2003 to 2013 // Int. J. Radiat. Oncol. Biol. Phys. – 2015. – Vol. 93. – Iss. 4. – P. 845–853. – https://doi.org/10.1016/j.ijrobp.2015.07.2292

28. Aznar M.C. [et al.] ESTRO-ACROP guideline: Recommendations on implementation of breath-hold techniques in radiotherapy // Radiother. Oncol. – 2023. – Vol. 185. – Art. 109734. – https://doi.org/10.1016/j.radonc.2023.109734

29. G. Loganadane [et al.] Comparison of Nodal Target Volume Definition in Breast Cancer Radiation Therapy According to RTOG Versus ESTRO Atlases: A Practical Review From the TransAtlantic Radiation Oncology Network (TRONE) // International Journal of Radiation Oncology Biology. Physics. – Elsevier Inc. – 2020.– Vol. 107. – No. 3.– P. 437–448. – https://doi.org/10.1016/j.ijrobp.2020.04.012

30. Beaton L., Bergman A., Nichol A., Aparicio M., Wong G., Gondara L. Cardiac death after breast radiotherapy and the QUANTEC cardiac guidelines. // Clin. Transl. Radiat Oncol. – 2019. – Vol. 13(19) – P. 39–45. – https://doi.org/10.1016/j.ctro.2019.08.001