Radiation dose to the heart with hypofractionation in patients with left breast cancer

Abstract

Introduction In this study we compared radiation dose received by organs at risk (OARs) after breast conservation surgery(BCS) and mastectomy in patients with left breast cancer. Materials and methods Total 30 patients, 15 each of BCS and mastectomy were included in this study. Planning Computerised Tomography (CT) was done for each patient. Chest wall, whole breast, heart, lungs, LAD, proximal and distal LAD, and contra lateral breast was contoured for each patient. Radiotherapy plans were made by standard tangent field. Dose prescribed was 40Gy/16#/3 weeks. Mean heart dose, LAD, proximal and distal LAD, mean and V5 of right lung, and mean, V5, V10 and V20 of left lung, mean dose and V2 of contra lateral breast were calculated for each patient and compared between BCS and mastectomy patients using student’s T test. Results Mean doses to the heart, LAD, proximal LAD and distal LAD were 3.364Gy, 16.06Gy, 2.7Gy, 27.5Gy; and 4.219Gy, 14.653Gy, 4.306Gy, 24.6Gy, respectively for mastectomy and BCS patients. Left lung mean dose, V5, V10 and V20 were 5.96Gy, 16%, 14%, 12.4%; and 7.69Gy, 21%, 18% and 16% in mastectomy and BCS patients, respectively. There was no statistical significant difference in the doses to the heart and left lung between mastectomy and BCS. Mean dose to the right lung was significantly less in mastectomy as compared to BCS, 0.29Gy vs. 0.51Gy, respectively (p = 0.007). Mean dose to the opposite breast was significantly lower in patients with mastectomy than BCS (0.54Gy Vs 0.37Gy, p = 0.007). The dose to the distal LAD was significantly higher than proximal LAD both in BCS (24.6Gy Vs 4.3Gy, p = <0.0001) and mastectomy (27.5Gy Vs 2.7Gy, p = <0.0001) patients. Conclusion There was no difference in doses received by heart and left lung between BCS and mastectomy patients. Mean doses to the right lung and breast were significantly less in mastectomy patients.

Accelerated hypofractionated breast radiotherapy with simultaneous integrated boost: a feasibility study

“…Mean dose to the right lung and the opposite breast was 0.29 Gy and 0.54 Gy, respectively. V 25 for heart was 4.25% [30]. In another study with 3D-CRT in left-sided patients with BCS, MHD in the supine and prone positions was 4.55 Gy and 2.06 Gy (p = 0.02), respectively.…”

“…However, this risk may vary with distance of the organ from the sternum, patient anatomy, dose optimization, set up errors, organ motion [42] and smoking [27]. In our past series we have reported second cancers in the contralateral breast, oesophagus and lung cancers in 3.3%, 0.22% and 0.05% patients, respectively [30].…”

Preliminary results of hypofractionated radiotherapy in breast cancer in Chandigarh, India: single-centre, non-inferiority, open-label, randomised, phase 3 trial

“…We have already reported the doses to the organs at risk with both radiation schedules. 13 , 14 It is very difficult to include internal mammary chain in a simple 3D conformal planning technique, and by anatomically marking the area we cannot be sure that the required dose has been delivered through a 2D planning technique. Although a 5% significance level for one-sided test is particularly common in non-inferiority trials but some researchers may also consider it at 2.5%.…”