Patients to be included in this study will be pre-operatively staged according to American Joint Committee on Cancer (AJCC) 7th edition, International Union against cancer ( which uses TNM staging ) as stage I , stage II of breast carcinoma. Fifty patients of histologically proven post lumpectomy cases of carcinoma breast suitable for whole breast radiotherapy will be enrolled in this study. Patients would be evaluated at the Department of Radiotherapy PGIMER, Chandigarh by doing a thorough clinical examination followed by routine investigations which will include hemogram, liver function tests, kidney function tests, chest X-ray. Patients will be treated by standard rectangular tangential field radiotherapy to whole breast. CT based planning will be done for photons boost and electron beam therapy.