Dosimetric comparison of heart dose with 3DCRT vs IMRT in post-mastectomy left sided chest wall irradiation

ABSTRACT

Purpose: Data regarding the efficacy of various radiotherapy techniques for post mastectomy chest-wall radiotherapy (PMRT) using hypofractionation is scarce and cardiac toxicity remains a concern. This study aims to compare effect of IMRT (Intensity Modulated Radiation Therapy) and 3D-CRT (3-Dimensional Conformal Radiation Therapy) techniques on cardiac dose. Materials and Methods: In this retrospective study, we compared IMRT and 3DCRT plans of 20 patients who received PMRT to a dose of 42.56Gy/16# and the dosimetric parameters in terms of planning target volume (PTV) coverage and dose to organ at risk (OARs) including heart and ipsilateral lung were recorded and analyzed. Result: PTV coverage were comparable with both techniques. IMRT planning provided a better conformity index as compared with 3DCRT (0.95 vs 0.91, p<0.001). The mean dose to the heart significantly reduced with IMRT (4.36Gy vs 8.2Gy, p<0.00001). Conclusion: IMRT offers a significant reduction in mean heart dose than 3DCRT in patients treated with hypofractionated post-mastectomy irradiation.