Patients undergoing a partial or total mastectomy and IBR and eligible for post-operative RT (as decided in the joint clinic) will be screened for the trial.  Patients will be randomized to conventional (Arm A 50 Gy in 25 fractions) or hypo-fractionation (Arm B 40 Gy in 15 fractions) arms. Randomization will be done by permuted blocks with the block length being varied randomly to minimise the effect of entry bias. All patients will receive 3-5 weeks of adjuvant RT as per the treatment arm allocated. It will be desirable to start adjuvant RT with 4-6 weeks of either the date of surgery or date of last chemotherapy whichever is relevant.

Pre and post treatment evaluation:

1          Quality of Life (QOL) forms:

All patients accrued in the trial will fill up the “Reconstruction module” of the BREAST-Q questionnaire which is specific for breast cancer patients undergoing reconstruction using abdominal flap, nipple or implant. The BREAST-Q is owned and copyrighted by Memorial Sloan-Kettering Cancer Center (MSKCC) and the University of British Columbia. The development and psychometric properties of this instrument have been published by the authors from MSKCC followed by subsequent reports of the validation of this instrument other institutes (22, 23, 24). As BREAST-Q was not available in Indian languages, the linguistic validation of the reconstruction module of this instrument was carried out and published by the principal investigator on this project (25,26). Hence this questionnaire will be used in the current project without any additional items or questions.

The satisfaction domains have 4-point Likert like response category options (“Very Dissatisfied”, “Somewhat Dissatisfied”, “Somewhat Satisfied” and “Very Satisfied”); physical and psychosocial domains have 5-point Likert like response category options (“None of the time”, “A Little of the time”, “Some of the time”, Most of the time” and “All of the time”) whereas the agreement domain has either 3 or 4 response category options (“Definitely Disagree”, “Somewhat Disagree”, “Somewhat Agree” and “Definitely Agree”). Two additional items to score arm edema and skin changes on the same 5 point and 4 point response format as BREAST-Q measure respectively will be used (these not being covered in the BREAST-Q). This assessment will be done at baseline (pre-op module prior to surgery and post op module prior to RT starting), and at 6, 12, 24, 42 and 60 months post randomization.

2          Clinical assessment of breast shrinkage/fibrosis

All patients will be followed up for routine clinical assessment at 6 monthly intervals for the first 5 years and yearly thereafter. Clinical data on skin fibrosis (centre, pectoral fold and infra-mammary fold), shrinkage, size and shape of the reconstructed breast will be recorded on the pre-printed case report forms and stored securely by the study team. This will be scored each on a 4-point graded scale (none, a little, quite a bit, very much). Other significant history of ischaemic heart disease, rib fracture and symptomatic lung fibrosis will also be recorded.

3          Morbidity assessment:

Major complications will be defined as those requiring corrective (revision) surgery (for wound complications or volume loss) or loss of reconstruction. Minor complications include infection, chest wall fibrosis, fat necrosis (FN), or contracture. The incidence and severity of the morbidity at the graft and donor sites will be recorded for each patient.

4       Radiologic assessment:

For assessing the periodic shrinkage of the reconstructed breast, volumetric assessment of the normal and reconstructed breast will be done on the institutional Mammography machine at baseline prior to RT and at 1, 2 and 3.5 and 5 years.

5          Photographic assessment: