Table 1 Characteristics of the included studies

Andrew 2016 [24]

197 (56/141)

DCIS

—

42.2–42.6 Gy/16f

45–50 Gy/25f

Retrospective

7

Ipsilateral recurrence rate; cosmetic effect

Biragitte 2020 [25]

1854 (917/937)

pT1-2, pN0-1

> 40

40 Gy/15f

50 Gy/25f

RCT

6

Breast depression, breast atrophy, breast pain, cosmetic effect, hyperpigmentation, edema, etc

Boon 2022 [14]

1608 (777/831)

DCIS

> 18

42–45 Gy/16f

50 Gy/25f

RCT

6

Time to local recurrence, overall survival, various toxicities, cosmetic effects, quality of life, etc

Brady 2022 [26]

331 (246/85)

T1-T2

29–87

40.05 Gy/15f

50 Gy/25f

Retrospective

8

Skin toxicities, etc

Chadha 2012 [27]

124 (50/74)

Tis, T1, T2

29–88

40.05 Gy/15f

46.8 Gy/26f

Retrospective

7

Skin toxicity, breast pain, breast edema, fatigue, and hematologic side effects, etc

Christopher 2012 [28]

1335 (1083/252)

T1-T2, N0, M0

48–66

42.5–44 Gy/16f

45–50 Gy/25

Retrospective

7

Local relapse, distant relapse, etc

Chuang 2021 [29]

718 (359/359)

pT1-2, pN0, M0

26–90

40-42 Gy/15–16 f

46-50 Gy/23–25 f

Retrospective

8

Ipsilateral recurrence rate, overall survival, acute skin toxicity, etc

Fabian 2005 [30]

129 (65/64)

pT1-2, pN0-1

—

2.5 Gy 4 × /week to 55 Gy

2.0 Gy 5 × /week to 55 Gy

Retrospective

6

Breast pain, breast fibrosis, breast atrophy, telangiectasia, lymphedema, etc

Felice 2017 [31]

120 (58/62)

invasive breast cancer

39–82

42.5 Gy/16f

50 Gy/25f

Retrospective

6

Acute skin toxicity, cardiac and lung toxicity

Grazia 2013 [32]

339 (198/141)

pT1-2, pN0-1

22–86

44 Gy/16f

50 Gy/25f

Retrospective

6

Acute skin toxicities

Hany 2012 [33]

107 (66/41)

invasive breast cancer

25–68

40 Gy/15f 45 Gy/17f

50 Gy/25f

Retrospective

7

Erythema, fibrosis, Pain, telangectesia, arm oedema, pigmentation, etc

Hou 2015 [34]

80 (40/40)

pT1-2N0-1M0

 ≥ 18

43.2 Gy/18f

45 Gy/25f

Retrospective

8

Locoregional recurrence, acute and advanced skin reactions, aesthetic outcome, etc

Joanne 2013 [8]

2215 (1110/1105)

pT1-3a, pN0-1, M0

—

41.6 Gy/13f 39 Gy/13f

50 Gy/25f

RCT

7

local–regional relapse, distant relapse, disease-free survival, overall survival, normal tissue effects, etc

Julie 2020 [35]

161 (79/82)

node-negative invasive carcinoma

—

42.56 Gy/16f

50 Gy/25f

RCT

5

Acute skin reactions, quality of life, etc

King 2020 [36]

1148 (532/615)

DCIS

≥ 18

42.5 Gy/16f

50 Gy/25f

RCT

7

Local recurrence, overall survival, cosmetic outcome, radiation toxicity, etc

Kitwadee 2021 [37]

73 (37/36)

T1-3N0-1M0

33–76

43.2 Gy/16f

50 Gy/25f

Retrospective

6

Disease free survival, overall survival and toxicity

Kumar 2018 [45]

101 (47/54)

—

—

40 Gy/15f

50 Gy/25f

Retrospective

8

Acute and chronic toxicities, locoregional response, etc

Lee 2016 [39]

758 (379/379)

pT1-2, pN0-1a

26–81

39 Gy/13f

50.4 Gy/28f

Retrospective

6

Ipsilateral breast tumor relapse, distant metastasis, overall survival, etc

Leonard 2020 [40]

140 (70/70)

DCIS/T1/T2

19–84

40.05 Gy/15f

50 Gy/25f

RCT

6

Acute radiation-induced skin toxicity, etc

Maiti 2020 [41]

222 (120/102)

T0-T4, N0-N3

25–70

40 Gy/15f

50 Gy/25f

Retrospective

7

Locoregional tumour recurrence and normal tissue toxicities

Mishra 2016 [42]

100 (56/44)

IB- IIIC

—

42.4 Gy/16f

50 Gy/25f

Retrospective

6

Local failure, distant failure, skin Toxicity, dysphagia, pulmonary, lymphoedema, etc

Rastogi 2017 [43]

100 (50/50)

—

21–66

42.72 Gy/16f

50 Gy/25f

RCT

4

Toxicity, tolerability, and locoregional control

Reshma 2015 [44]

2309 (578/1731)

Tis-T4

—

single > 2 Gy

single ≤ 2 Gy

Retrospective

9

Dermatitis, pain, fatigue, and other common toxic effects

Sanjal 2018 [38]

60 (30/30)

T3, T4 Nx, N0 to N3

> 45

40.05 Gy/15f

50 Gy/25f

Retrospective

7

Pulmonary, cardiac, dermatological, toxicities and lymphoedema. feasibility option, local control

Simona 2015 [46]

287 (138/149)

Tis-T2, N0-N1a, M0

≥ 40

42.56 Gy/16 f

50 Gy/25f

RCT

6

Acute dermatitis, hyperpigmentation, fatigue, breast pain, pruritus etc

Simona 2018 [47]

287 (138/149)

TisT2N0-N1M0

≥ 40

42.56 Gy/16 f

50 Gy/25f

RCT

6

Functional status, local recurrences, distant metastasis, breast pain, cosmetic etc

Tomo 2008 [48]

443 (66/377)

Tis-T4

19–81

40 Gy/16 f

50 Gy/25f

Retrospective

7

Acute radiation dermatitis and pneumonitis

Vassilis 2016 [49]

117 (87/30)

T2-T4

33–78

42.56 Gy/16 f 48.3 Gy/21 f

50 Gy/25f

Retrospective

6

Acute and late skin toxicity

Volker 2016 [50]

266 (121/145)

Tis-T4

—

40.05 Gy/15 f

50 Gy/25f

Retrospective

6

Skin toxicity

Wang 2019 [51]

820 (406/414)

T3-T4

18–75

43.5 Gy/15 f

50 Gy/25f

RCT

7

Locoregional recurrence, overall survival, disease-free survival, and acute and late radiation toxicities

Wang 2020 [16]

734 (368/366)

T1-2N0-3

—

43.5 Gy/15 f

50 Gy/25f

RCT

7

Local Relapse, survival outcomes, toxicity and cosmesis

Weng 2021 [54]

287 (138/149)

DCIS or Tis-T2, N0-N1a, M0

≥ 40

42.56 Gy/16 f

50 Gy/25f

RCT

6

Breast pain, cosmesis, etc

Whelan 2010 [5]

455 (235/220)

invasive carcinoma

—

42.5 Gy/16 f

50 Gy/25f

RCT

7

Local Recurrence, and skin toxicity

Xu 2018 [52]

114 (83/31)

T0-3N0-1

—

40.05 Gy/15 f

50 Gy/25f

Retrospective

7

Skin toxicities

Zhao 2017 [53]

107 (53/54)

pT1-2, pN0-1, and pMx

—

42.56 Gy/16 f

50 Gy/25f

Retrospective

7

Local recurrence, distant metastasis, cosmetic and delayed toxic effects