Purpose: Radiation treatment to the left breast is associated with increased cardiac morbidity and mortality. The deep inspiration breath-hold technique (DIBH) can decrease the radiation dose delivered to the heart and lung. Deep Inspiration Breath-hold, utilizing a respiration-monitoring device by using an LPT system has been used in our clinic to reduce the cardiac dose and lung dose for patients receiving left-sided breast irradiation compared to free-breathing (FB).
Methods: Between July and October 2015, a total of 10 patients with left-sided breast cancer underwent two computed tomography scans each with the DIBH using the LPT system and using FB after mastectomy. The scans were retrospectively re-planned using standardized criteria for the purpose of this study. Treatment plans were generated by the 3DCRT technique. The DIBH plans for each patient were compared with FB plans using dosimetric parameters.
Results: All patients were successfully planned with the DIBH technique using the LPT system. Significant differences were found between the DIBH and FB plans for mean heart dose (4.49 vs. 5.95Gy,p=0.009), heart V30 (4.74 vs.6.82 %,p=0.006), V20 (6.41vs.9.12 %,p=0.004),and mean left anterior descending coronary artery (LAD) dose (20.39 vs. 24.93Gy, p<0.001).The mean left lung dose (8.18 vs. 9.29Gy, p=0.001) and lung V20 (20.26 vs. 21.82%, p=0.1366). There was no significant difference in the mean left lung dose, mean right lung or mean dose to the contralateral breast.
Conclusion: This study reports that the use of a DIBH technique using LPT system in breathing adapted radiotherapy for left-sided breast cancer is easily feasible in daily practice and significantly reduces the radiation doses to the heart, LAD and lung, therefore potentially reducing cardiac risk.
Not Applicable / None Entered.
TH- External Beam- Photons: treatment planning/virtual clinical studies