***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    Input: Summary Background The international st and ard radiotherapy schedule for early breast cancer delivers 50 Gy in 25 fractions of 2·0 Gy over 5 weeks , but there is a long history of non-st and ard regimens delivering a lower total dose using fewer , larger fractions ( hypofractionation ) . We aim ed to test the benefits of radiotherapy schedules using fraction sizes larger than 2·0 Gy in terms of local-regional tumour control , normal tissue responses , quality of life , and economic consequences in women prescribed post-operative radiotherapy . Methods Between 1999 and 2001 , 2215 women with early breast cancer ( pT1 - 3a pN0 - 1 M0 ) at 23 centres in the UK were r and omly assigned after primary surgery to receive 50 Gy in 25 fractions of 2·0 Gy over 5 weeks or 40 Gy in 15 fractions of 2·67 Gy over 3 weeks . Women were eligible for the trial if they were aged over 18 years , did not have an immediate reconstruction , and were available for follow-up . R and omisation method was computer generated and was not blinded . The protocol -specified principal endpoints were local-regional tumour relapse , defined as reappearance of cancer at irradiated sites , late normal tissue effects , and quality of life . Analysis was by intention to treat . This study is registered as an International St and ard R and omised Controlled Trial , number IS RCT N59368779 . Findings 1105 women were assigned to the 50 Gy group and 1110 to the 40 Gy group . After a median follow up of 6·0 years ( IQR 5·0–6·2 ) the rate of local-regional tumour relapse at 5 years was 2·2 % ( 95 % CI 1·3–3·1 ) in the 40 Gy group and 3·3 % ( 95 % CI 2·2 to 4·5 ) in the 50 Gy group , representing an absolute difference of −0·7 % ( 95 % CI −1·7 % to 0·9%)—ie , the absolute difference in local-regional relapse could be up to 1·7 % better and at most 1 % worse after 40 Gy than after 50 Gy . Photographic and patient self- assessment s indicated lower rates of late adverse effects after 40 Gy than after 50 Gy . Interpretation A radiation schedule delivering 40 Gy in 15 fractions seems to offer rates of local-regional tumour relapse and late adverse effects at least as favourable as the st and ard schedule of 50 Gy in 25 fractions OBJECTIVE Concomitant chemo-radiotherapy after modified radical mastectomy for breast cancer is an effective means of achieving high survival rates . In this study different radiotherapy optimization regimens are compared to assess their effectiveness and toxicity rates . PATIENTS AND METHODS 112 patients with modified radical mastectomy participated , and were r and omly assigned to one of three groups , all receiving adjuvant chemotherapy for 4 - 6 weeks prior to radiotherapy  : group A received intensity modulated radiotherapy ( radiation dose ( DT ) 50 Gy , 2.0 Gy/fraction , 25 times , during the course of 33 - 35 days ) ; group B received concurrent radio chemotherapy and intensity modulated radiotherapy ; and group C adopted concurrent radio chemotherapy and hypofractionation ( DT of 42.56 Gy , 2.66Gy/fraction , 16 times , during the course of 22 - 24 days ) with 37 cases . The occurrence of acute and chronic radiation injuries , the cancer recurrence and the survival rates were compared , and a dose volume histogram ( DVH ) was created . RESULTS The total prevalence and survival rates of Group C were significantly better than those of the other two groups ( p ≤ 0.05 ) ; in spite of the fact that the local recurrence and distant metastasis rates separately were all statistically the same ( p ≥ 0.05 ) . Also , the total radiation injury occurrence of group C was significantly lower ( p < 0.05 ) ; but no significant differences were found when singling out acute and chronic injury occurrences or injury severity between the three groups . The values of V5 , V10 , V20 and V30 increased gradually in all of the groups , and V5 and V10 in Group C were higher than those in the other two groups , but the comparison between V20 and V30 yielded no statistically significant differences . CONCLUSIONS Based on these results , the concurrence of hypo-fractionation radiotherapy and chemotherapy may be an effective and safe approach for cancer treatment after modified radical mastectomy , and larger studies are warranted given the convenience of the method BACKGROUND 5-year results of the UK St and ardisation of Breast Radiotherapy ( START ) trials suggested that lower total doses of radiotherapy delivered in fewer , larger doses ( fractions ) are at least as safe and effective as the historical st and ard regimen ( 50 Gy in 25 fractions ) for women after primary surgery for early breast cancer . In this prespecified analysis , we report the 10-year follow-up of the START trials testing 13 fraction and 15 fraction regimens . METHODS From 1999 to 2002 , women with completely excised invasive breast cancer ( pT1 - 3a , pN0 - 1 , M0 ) were enrolled from 35 UK radiotherapy centres . Patients were r and omly assigned to a treatment regimen after primary surgery followed by chemotherapy and endocrine treatment ( where prescribed ) . R and omisation was computer-generated and stratified by centre , type of primary surgery ( breast-conservation surgery or mastectomy ) , and tumour bed boost radiotherapy . In START-A , a regimen of 50 Gy in 25 fractions over 5 weeks was compared with 41·6 Gy or 39 Gy in 13 fractions over 5 weeks . In START-B , a regimen of 50 Gy in 25 fractions over 5 weeks was compared with 40 Gy in 15 fractions over 3 weeks . Eligibility criteria included age older than 18 years and no immediate surgical reconstruction . Primary endpoints were local-regional tumour relapse and late normal tissue effects . Analysis was by intention to treat . Follow-up data are still being collected . This study is registered as an International St and ard R and omised Controlled Trial , number IS RCT N59368779 . FINDINGS START-A enrolled 2236 women . Median follow-up was 9·3 years ( IQR 8·0 - 10·0 ) , after which 139 local-regional relapses had occurred . 10-year rates of local-regional relapse did not differ significantly between the 41·6 Gy and 50 Gy regimen groups ( 6·3 % , 95 % CI 4·7 - 8·5 vs 7·4 % , 5·5 - 10·0 ; hazard ratio [ HR ] 0·91 , 95 % CI 0·59 - 1·38 ; p=0·65 ) or the 39 Gy ( 8·8 % , 95 % CI 6·7 - 11·4 ) and 50 Gy regimen groups ( HR 1·18 , 95 % CI 0·79 - 1·76 ; p=0·41 ) . In START-A , moderate or marked breast in duration , telangiectasia , and breast oedema were significantly less common normal tissue effects in the 39 Gy group than in the 50 Gy group . Normal tissue effects did not differ significantly between 41·6 Gy and 50 Gy groups . START-B enrolled 2215 women . Median follow-up was 9·9 years ( IQR 7·5 - 10·1 ) , after which 95 local-regional relapses had occurred . The proportion of patients with local-regional relapse at 10 years did not differ significantly between the 40 Gy group ( 4·3 % , 95 % CI 3·2 - 5·9 ) and the 50 Gy group ( 5·5 % , 95 % CI 4·2 - 7·2 ; HR 0·77 , 95 % CI 0·51 - 1·16 ; p=0·21 ) . In START-B , breast shrinkage , telangiectasia , and breast oedema were significantly less common normal tissue effects in the 40 Gy group than in the 50 Gy group . INTERPRETATION Long-term follow-up confirms that appropriately dosed hypofractionated radiotherapy is safe and effective for patients with early breast cancer . The results support the continued use of 40 Gy in 15 fractions , which has already been adopted by most UK centres as the st and ard of care for women requiring adjuvant radiotherapy for invasive early breast cancer . FUNDING Cancer Research UK , UK Medical Research Council , UK Department of Health Purpose Conventionally fractionated postmastectomy radiation therapy ( PMRT ) takes approximately 5 to 6 weeks . Data supporting hypofractionated PMRT is limited . We prospect ively evaluated a short course of hypofractionated PMRT , in which therapy was completed in 15 treatment days . Patients and Methods We delivered PMRT at a dose of 36.63 Gy in 11 fractions of 3.33 Gy over 11 days to the chest wall and the draining regional lymph nodes , followed by an optional mastectomy scar boost of four fractions of 3.33 Gy . Our primary end point was freedom from any grade 3 or higher toxicities . We incorporated early stopping criteria on the basis of predefined toxicity thresholds . Results We enrolled 69 women with stage II to IIIa breast cancer , of whom 67 were eligible for analysis . After a median follow-up of 32 months , there were no grade 3 toxicities . There were 29 reported grade 2 toxicities , with grade 2 skin toxicities being the most frequent ( 16 of 67 ; 24 % ) . There were two patients with isolated ipsilateral chest wall tumor recurrences ( 2 of 67 ; crude rate , 3 % ) . Three-year estimated local recurrence-free survival was 89.2 % ( 95 % CI , 0.748 to 0.956 ) . The 3-year estimated distant recurrence-free survival was 90.3 % ( 95 % CI , 0.797 to 0.956 ) . Forty-one patients had chest wall reconstructions ; three had exp and ers removed for infection before radiation therapy . The total rate of implant loss or failure was 24 % ( 9 of 38 ) , and the unplanned surgical correction rate was 8 % ( 3 of 38 ) , for a total complication rate of 32 % . Conclusion To our knowledge , our phase II prospect i ve study offers one of the shortest courses of PMRT reported , delivered in 11 fractions to the chest wall and nodes and 15 fractions inclusive of a boost . We demonstrated low toxicity and high local control with this schedule . On the basis of our data , we have design ed a cooperative group phase III prospect i ve , r and omized trial of conventional versus hypofractionated PMRT that will activate soon Introduction : The aim of this analysis was a retrospective evaluation of the efficacy and toxicity of 2 hypofractionated irradiation schedules compared to conventional therapy in post-mastectomy patients . Methods : 3 irradiation schedules were analyzed : 48.30 Gy in 21 fractions ( group A , n = 60 ) , 42.56 Gy in 16 fractions ( group B , n = 27 ) and 50 Gy in 25 fractions ( group C , n = 30 ) of the front chest wall . All groups were also treated with a supraclavicular field , with 39.10 Gy in 17 fractions ( group A ) , 37.24 Gy in 14 fractions ( group B ) or 45 Gy in 25 fractions ( group C ) . Results : No local recurrences were noted in any group during 36 months of follow-up . Acute skin toxicity presented in all groups , with 58.3 % , 70.4 % and 60 % of grade I ; 35 % , 25.9 % and 40 % of grade II ; 6.7 % , 3.7 % and 0 % of grade III being seen in groups A , B and C , respectively . Late skin toxicity was noted only as grade I in 16.7 % , 25.9 % and 26.7 % of groups A , B and C , respectively . No significant difference was noted among all groups for either acute or late skin toxicity , or for radio-pneumonitis ( chi2 test , p > 0.05 ) . Conclusion : All schedules were equally effective with equivalent toxicity . A prospect i ve r and omized study is needed to confirm our results Background Several r and omized trials and meta-analyses confirmed a wide benefit of radiotherapy ( RT ) , both after breast conserving surgery ( BCS ) and mastectomy . However , many elderly women do n't receive RT . Hypofractionated ( HF ) RT allows « simplified » and more accessible treatments with equivalent results to classic RT in three large r and omized trials . However , there are few available data on HF-RT for nodal irradiation , as well as for the boost . Methods We evaluated patients treated for IBC by HF-RT between 2004 and 2012 in two regional cancer centres . We used an original scheme delivering 45 Gy in 15 fractions three times a week , both after BCS or mastectomy , with or without nodal irradiation . After BCS , a 9 Gy boost in 3 fractions was delivered . Local , regional and distant recurrences were assessed , as well as acute and late cutaneous , cardiac or pulmonary toxicities . Results 
    Output:
    
Conclusions The results of this study show that compared to conventional fractionated radiotherapy , hypofractionated radiotherapy is not significantly different with respect to efficacy or toxicity in postmastectomy breast cancer .