Radiotherapy Protocol for the management of BREAST Cancer 

This is radiotherapy protocol for the East Midlands RT Operational Delivery Network (ODN). 
Tumour sites are: Breast 

Document revision History 

Version Number 

Date 

Document History. 

0.01 

03/02/2023 

Initial Draft by Priyesh Mistry 

0.02 

31/07/2023 

Reviewed and amended with KD 

0.03 

11/10/2023 

Changes following 1st Network review. 

In attendance: 

A.Aleksic, K.Das, W.Ali, K.Johnson, 
K.Kancherla, R.Vijyan 

0.04 

11/23 

Changes following planning and physics 
departmental (UHL/UHDB/NUH) 
feedback in person with PM 

0.06 

02/2024 

Changes following feedback regarding 
planning section from M.Cowen 

0.06 

23/04/2024 

Reviewed by Radiotherapy planning 
team. 

In attendance: 

D.Holmes, L.Martins. V. M-Smith, J. 
Sutton 

Updated draft shared to planning team 
for any further comments 

0.07 

27/09/2024 

Reviewed and ratified at ECAG 

1.0 

October 2024 

Uploaded to Sharepoint 

V1.1 

March 2025 

KD/PM- References improved as per 
Dec 2024 NOG action 



 

 

 

 

 

 

 

 

 

 


 

 

Radiotherapy Protocol for the management of BREAST Cancer ................................................................ 1 
1. Treatments to include ...................................................................................................................... 3 
2. Indications for treatment ................................................................................................................. 3 
2.1. Whole breast radiotherapy .......................................................................................................... 3 
2.2. Partial Breast Radiotherapy [20] [15] ............................................................................................... 3 
2.3. Omission of RT Only ..................................................................................................................... 3 
2.4. Chestwall radiotherapy (+/- Reconstruction) [21] ........................................................................ 4 
2.5. Nodal Irradiation [1] ...................................................................................................................... 4 
2.6. Tumour Bed Boost Radiotherapy [1] ............................................................................................. 4 
2.7. Considerations .............................................................................................................................. 4 
2.8. NACT ............................................................................................................................................. 5 
3. Investigations Required ................................................................................................................... 5 
4. Information given to patients .......................................................................................................... 5 
5. Consent ............................................................................................................................................. 5 
6. Trials Open ........................................................................................................................................ 5 
7. Position and immobilisation ............................................................................................................ 6 
8. Planning ............................................................................................................................................ 6 
9. Bolus ................................................................................................................................................. 7 
10. OAR: Organs at risk & dose contraints ........................................................................................ 8 
11. Dose Fractionations [1] ................................................................................................................ 11 
12. Palliative Intent .......................................................................................................................... 11 
10. Treatment ................................................................................................................................... 12 
11. Late effects ................................................................................................................................. 12 
12. Peer Review [22] ........................................................................................................................... 12 
13. Glossary ...................................................................................................................................... 13 
14. References .................................................................................................................................. 14 



 Whole breast Radiotherapy 
 Partial breast Radiotherapy 
 Chest wall (+/- Reconstruction) Radiotherapy 
 Nodal irradiation 
 Tumour bed boost 
 Special cases 




1. Treatments to include 

 

2. Indications for treatment 

 

Adjuvant Radiotherapy 

2.1. Whole breast radiotherapy 




 Breast conserving surgery with clear margins for: 

 Invasive carcinoma 
 DCIS with high risk 
 DCIS with intermediate risk (Reference VNPI to guide decision) 
 Encysted papillary carcinoma 
 Pleomorphic lobular carcinoma in situ 




 

 

2.2. Partial Breast Radiotherapy [20] [15] 




For patients that meet all the following criteria 

 Breast conserving surgery for invasive cancer 
 Age ≥ 50 Years 
 Tumour ≤ 30mm 
 Grade 1 and 2 disease 
 Minimum of 1mm radial margins 
 Node negative 
 ER positive HER negative 


Exclusion criteria 

 Classical Lobular carcinoma 
 Lymph-vascular invasion 


 

-Patients should be advised to have adjuvant endocrine therapy 



 

2.3. Omission of RT Only 




Omission of RT only 

 

 NICE 2018 guidance [3] recommends to consider omitting radiotherapy in women who have a 
very low absolute risk of local recurrence (defined as women aged 65 and over with tumours 
T1N0, ER-positive, HER2-negative and grade 1-2) willing to take adjuvant endocrine therapy for 
a minimum of five years. 





 

2.4. Chestwall radiotherapy (+/- Reconstruction) [21] 




 4 or more LN +ve 
 Involvement of deep margin or skin 
 All tumour > 5 cm 
 Consider RT if any of 


- size > 3cm 

- LN +ve 

- Grade 3 

- Lympho-vascular invasion 



 

2.5. Nodal Irradiation [1] 




Consider supraclavicular fossa radiotherapy (SCF) treatment: 

 N2/N3 (≥ 4 lymph nodes positive) 


1-3 lymph nodes positive in patients with good performance score and other poor prognostic 
features in patients such as grade 3 disease, T3/4 tumours, lymph vascular invasion and extra 
capsular spread. Consider if grade 2 and high risk features 

 

Consider Internal mammary chain nodal radiotherapy: 

 T4 and/or N2-N3 
 Intermediate risk of recurrence (that is, 1–3 axillary macrometastases and central/medial 
disease, who have been recommended locoregional irradiation 


 

Axillary node radiotherapy 

 Axillary surgery not possible 
 Consider in selected patients with macroscopic metastases following sentinel node biopsy 
where further axillary treatment (axillary surgery or axillary radiotherapy) is required. 


Individualised treatment as per MDT discussion and patient choice. Axillary lymph node clearance 
preferred in patients who present with macroscopic disease in the axilla including bulky disease. 



 

2.6. Tumour Bed Boost Radiotherapy [1] 




 Age ≤ 50 years 
 Grade 3 
 Extensive intraductal component 
 Positive margins and close resection margins of <1mm where no further surgical excision is 
possible in invasive disease. 


Consider boost in cases of DCIS with positive margins that cannot be re-excised to be discussed on a 
case by case basis in the MDT meeting (Meena et al, 2017) [2] 



 

2.7. Considerations 




DIBH 

 All left sided breast cancers [1] 
 Right sided breast cancer where the left has been irradiated in DIBH 
 Consider right sided cancer in a large breast to reduce the amount of liver in the field 
 Internal mammary chain lymph nodes in both left and right sided disease [1] 





 Consider for right sided breast treatment where SCF and/or axilla are to be treated 




 

Bilateral Breast/Chestwall treatment 

 Simultaneous or sequential as per local practice 
 DIBH recommended for both sides 
 If for nodal radiotherapy on one or both sides, treatment with VMAT/Rapidarc simultaneous 
(40gy in 15#) should be considered 


-Alternatively: Matched tangents with a central gap 



 

2.8. NACT 




Neoadjuvant chemotherapy (NACT) 

 

 Base the indication for adjuvant radiotherapy on the pre NACT clinical staging 
 Pre NACT node positive (includes post NACT residual nodal disease and pathological evidence of 
previous nodal involvement) 


 



 

3. Investigations Required 

 Histological confirmation of malignancy 
 Diagnostic/staging imaging to include: 


-CT chest/abdomen/pelvis (if indicated) 

-MRI (if indicated) 

Review of clinical history to include: 

-Previous radiotherapy 

-History and examination, PS 

Special Circumstances to consider: 

-Chronic conditions or disease that affects radiosensitivity 

-Ongoing medication that may affect response to radiotherapy 

-Patients with an ICD (RCR ICD GUIDANCE) [4] 



 

4. Information given to patients 

 General radiotherapy booklet 
 Site specific treatment leaflet including long term side effects 




 

5. Consent 

 By IR(ME)R Practitioner at new patient / planning clinic 
 By Entitled IR(ME)R Operator under delegated authority at new patient / planning clinic 




 

6. Trials Open 

 Consider current trials open in any of the radiotherapy centres in the East Midlands. 


[EMRTN TRIALS TRACKER LINK] 

 If a patient is being treated in a clinical trial then the Trial Protocol overrides the departmental 
protocol. 





7. Position and immobilisation 

All patients will be CT scanned as per local protocol and should consider including the following: 

 Appropriate scan levels incorporating the treatment area and OAR 
 Suitable breast/thorax patient immobilisation utilising incline as appropriate 
 Patients should be supine with their arm(s) above their head 
 Consideration should be taken into account to reduce treatment collision risk (i.e. width 
between elbows and incline) in line with local planning and treatment restrictions 
 Radio-opaque markers to delineate breast tissue, scars and disease 
 Use of IV contrast if required, as per local protocol 




 

8. Planning 

Target volumes: Use ESTRO contouring atlas as a guide[5] 

 

Breast & Chest wall 

Routine outlining is not required. Fields are defined based on the patients anatomy using virtual 
simulation and a pseudo PTV is created. 

Breast/chest wall are outlined when RapidArc/VMAT is required (due to patient anatomy or treatment 
include nodes) 

RapidArc/VMAT may be used to treat any SCF/Axilla/IMLN patients according to local practice. 

RapidArc/VMAT may also be used to treat breast only patients and should be decided on case by case 
basis. 

CTV_WB: Whole breast CTV includes the soft tissues of the whole breast from 5 mm below the skin 
surface down to the deep fascia, excluding muscle and underlying rib cage. PTV as per local 
practice. 

CTV_CW: Chest wall CTV is from skin flaps and includes the soft tissues down to the deep fascia, 
excluding underlying muscle and rib cage. PTV as per local practice 

 



 

Partial breast [15] 

GTV = clips + surgical changes 

PB_CTV = GTV + 15mm margin bound 5mm from skin surface and 5mm from lung/chest wall interface 
but should not extend into pectoral fascia nor beyond visible breast tissue 

PB_PTV = PB_CTV + 10mm 

PB_PTV_DVH = PB_CTV + 10mm bound 5mm from skin surface and 5mm from lung. 

Also, bound 5mm from field boundary, only after acknowledgement and justification from clinician Field 
= PB_PTV + 7-10mm 



 

 

Tumour Bed Boost 

Aim to treat surgical bed using surgical clips as guidance if appropriate. Add PTV and fields as per local 
practice (consider IMPORT methodology for guidance[11]). Take consideration if patient is in DIBH for 
boost treatment. Boost volume is treated either with photons as part of simultaneous integrated boost 
or sequentially with photons/electrons. 

Dose constraints should account for boost and ideally should be planned together, but may be planned 
separately (i.e. Treatment with SIB is preferable) 




 

 

 

SCF 

To include level 3 + level 4 nodes. 

The nodal areas are outlined by the consultant or advanced practitioner. PTV and field are placed as per 
local practice. 

Alternatively, centers may use fields based on anatomical land marks but need to ensure that the nodal 
areas are covered 



 

 

Axilla: 

Level 1 & Level 2 nodes need to be included. 

The nodes are outline and PTV and fields are placed as per local practice. 

If not for VMAT/Rapidarc: The volume is covered by a direct anterior field matched with the breast 
tangents. It is expected that the part of this volume is covered by breast tangent and part of the volume 
by the axillary field. Alternatively, centers may use a wide breast tangent to treat the axilla 



 

 

SCF & Axilla: 

Volumes to include SCF and axilla as above and PTV and fields as per local practice. 

If not for VMAT/Rapidarc: Alternatively fields based on anatomical landmarks to cover the nodal areas 
may be used. Shielding to cover humeral head. 



 

 

IMLN: 

Internal mammary nodes and SCF nodes CTV is outlined by Consultant or by trained advanced 
practitioner. Breast / chest wall CTV is also outlined. PTV used as per local practice. 

IMLN, SCF & Breast/Chest wall PTV is treated by VMAT/Rapidarc 

If not for VMAT/Rapidarc : Deep breast tangents can be considered if more appropriate. 



 

 

9. Bolus 

If the skin is considered the target organ (known skin involvement, inflammatory disease or where risk 
of recurrence at skin surface is considered to be high) bolus will be prescribed for all fractions. Bolus 
thickness will be decided based upon treatment plan dosimetry. 

N.B. In this situation, bolus may be removed towards the end of treatment if there is a marked acute 
skin reaction 



 

 


 

 

10. OAR: Organs at risk & dose contraints 

 

OAR to be outlined by planning staff and approved by responsible clinician. OAR to be included: 

Heart, Lung- ipsilateral and contralateral, contralateral breast (VMAT), spinal cord (VMAT) 

Dose constraints for OAR are generally prioritised over the target coverage constraints. The volume of 
lung and heart treated should be reduced by MLC shielding. 



 

 

 

 

Dose objectives for PTV'S 

 

 Treatment plans should be prescribed as per the local protocol for breast planning 
 Local protocols should also decipher decisions regarding PTV cropping. 


 

Breast 

V95% ≥ 95% (optimal) 

V95% ≥ 90% (mandatory) 

D0.5cc ≤ 110% (mandatory) 

Boost 

 

V95% ≥ 95% (optimal) 

V95% ≥ 90% (mandatory) 

V107% ≤ 2% (mandatory) 

SCF, Axilla, IMLN 

V90% ≥90% (optimal) 

V80% ≥ 80% (Mandatory) 



 

 

 

 

 

 

 

 


 This protocol has referenced several protocols for the OAR constraints. Other protocols that may incorporate tighter constraints (e.g. ESTRO guidance [16] ) may also be used 


 

Local protocols can be adapted to incorporate any of the clinically acceptable guidance protocols as per departmental preference 

 



 

Dose 
constraints 

Tangents 

VMAT/RAPIDARC 

Dose 

26Gy in 5# / 28.5Gy in 5# 

40GY in 15# 

40GY in 15# / 48Gy in 15# 

40GY in 15# 

 

Breast / Chestwall / Partial breast 

(Based on FAST FORWARD trial) 
[13] 

Breast / Chestwall / Partial breast 
+ Specified Nodes 

(Based on IMPORT HIGH)
[11] 

Breast / Chestwall / Partial 
breast + Specified Nodes + 
Boost 

 (Based on UK RCR Consensus 2016 & Import 
HIGH)
[11] [12] 

 

Breast / Chestwall / + Specified 
Nodes +/- Boost 

(Based on UK RCR Consensus 2016 & 

 Import HIGH)
[11] [12] 

OAR 

Dose 

Mandatory 
constraint 

Optimal 
Constraint 

Dose 

Mandatory 
constraint 

Optimal 
Constraint 

Dose 

Mandatory 
constraint 

Optimal 
Constraint 

Dose 

Mandatory 
constraint 

Optimal Constraint 

 

 

 

Heart 

 

V6.5Gy 

 

≤ 5% 
mandatory 

- 

V10Gy 

 

≤ 10% 

 

≤ 5% 

 

V10Gy 

 

≤ 10% 

 

≤ 5% 

 

Mean 

 

- 

<2Gy 

(Right sided) 

 

V1.3GY 

 

≤30% 
mandatory 

- 

Mean Dose 

- 

<2Gy 

V2Gy 

- 

< 30% 

V2Gy 

- 

< 30% 

- 

- 

- 

- 

- 

Complete 
shielding of the 
heart 

Mean dose 

≤2Gy 

- 

Mean 
dose 

≤2Gy 

- 

- 

- 

- 

Heart (IMC) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

V17Gy 

≤10% 

≤10% 

Mean[9] 

≤6Gy 

≤4Gy 

Ipsilateral lung 

(Non IMC) 

V7.8Gy 

≤17% 

≤15% 

V18Gy 

<15% 

<10% 

V18Gy 

<15% 

<10% 

 

V12Gy 

- 

≤25.0% 

Mean 

- 

<6Gy 

V18Gy 

<30% 

- 

Ipsilateral lung + 
SCF 

- 

- 

- 

V18Gy 

- 

≤30% 

- 

- 

- 

- 

- 

- 

Ipsilateral lung 

(IMC) 

- 

- 

- 

- 

- 

- 

- 

- 

- 

V17GY 

≤35.0% 

- 

Mean 

- 

≤ 13.0Gy Optimal 

Contralateral breast 

- 

- 

- 

- 

- 

- 

- 

- 

- 

Mean 

≤3.5Gy 

≤1.5Gy if>40year 

≤1Gy if ≤40 years 

Contralateral lung 

- 

- 

- 

- 

- 

 

- 

- 

- 

- 

Mean 

≤4.0GY 

≤3.5Gy[9] 



 


Additional OAR for consideration 

OAR 

Dose considerations (Report only or as per local practice) 

Brachial plexus [8] 

Dose to 0.10cc less than 42Gy 

Left anterior descending artery 
(LAD) [18] 

Less than 12Gy total dose ( 0.8 Gy per fraction) IMC etc. 

Thyroid [17] 

V30Gy< 50% 

Trachea 

 

D0.1cc<33Gy 

 

D0.1cc<30Gy + 5mm (PRV) 

 

Oesophagus [14] 

 

V17<15% 

 

mean<11Gy 

 

 

Spinal cord dose 

12-14Gy for IMC treatments with VMAT 

Head of humerus [8] 

V40Gy < 1cc 

 



 

 


11. Dose Fractionations [1] 

 

 

Breast/Partial Breast/Chest wall /Reconstruction 

 26Gy in 5 fractions over 1 wk 
 28.5Gy in 5 fractions over 5 wks for frail patients[12] 
 40Gy in 15 fractions over 3 wks (for patients requiring breast boost only) 


 



 

Breast/Chest wall plus nodes (SCF, Axilla, IMLN) 

 40GY in 15 fractions over 3wks 
 26GY in 5 fractions for frail patients, excluding patients needing IMLN[6] 


 



 

Breast Boost 

 13.35Gy in 5# or 12GYin 4# (Hypofractionated boost) (Grade C). Sequential following 26Gy in 5# 
or 40GY in 15#; whichever dose schedule is used, should be equivalent to 16GY in 8# 
 15# in SIB (Simultaneous integrated). 48Gy to boost volume and 40Gy to rest of the breast 
(Grade A) 


 



 

 

12. Palliative Intent 

 Bespoke treatment to palliate locally advanced and metastatic disease to achieve local tumour 
control and symptom control 
 Medically inoperable breast cancer 
 Conformal Radiotherapy is the primary choice of planning technique for palliative patients. 
However IMRT/VMAT Radiotherapy will be considered where it is justifiably, patient appropriate 
and also in circumstances where constraints/targets cannot be achieved through conformal 
Radiotherapy 


Dose Fractionations: [1] 

 20Gy in 5# 
 26Gy in 5# 
 40Gy in 15# 
 30GY-36GY over 5-6 weeks 
 8Gy in 1# 




 

 

 

 

 

 

 


10. Treatment 

 

 Final pre-treatment, Physics and 1st day checks should be carried out as per local protocol. 
 These should ideally cover or take into account the following: 


-Monitoring and managing Radiotherapy delays to ensure patients start treatment according to 
national guidelines 

-Checking plan approval status and parameters as per local protocol 

-All prior preparatory and required patient information is available 

-Imaging requirements for the planned treatment are adequate according to patient plan and 
local protocol 

-Any prior In vivo dosimetry has been performed as per local protocol. 

 During treatment: 


-Any other monitoring as specified in the local protocol should be performed e.g. dietician 
review, weight checks, weekly blood counts. 

-On treatment imaging as per local protocols 

 For gaps in treatment follow local policy which should take into account the RCR policy[19] 
 On treatment and follow up reviews as per local protocols. 
 SGRT is recommended for the treatment of breast patients and should be used as per local 
protocol. 


-Where SGRT is not available alternative motion management should be considered. 



 

11. Late effects 

 

 Late effects will have been discussed as part of the initial discussions and counselling by the 
treating clinician and is dependent on the radiotherapy target volumes 


 

 If available, details of the local department’s late effects clinic should be provided at the 
appropriate interval following completion of Radiotherapy. 


 



 

12. Peer Review [22] 

 Peer Review will enable clinicians to provide high quality treatments despite potentially limited 
referrals. Documenting peer review is essential as per RCR Recommendation 10 + 11. 
 In order to meet the RCR standards the review will cover patient selection, prescription and 
target / OAR delineation. For some cases it may be necessary to review the final treatment plan 
also. 
 The reviewee must provide the reviewer with all relevant clinical information to peer review, 
which may include demographics, diagnosis and details of proposed treatment. Any relevant 
clinical tests or images must also be provided (see Table 1 above). 
 Responsibility for the patient will remain with the clinician under whom the patient receives 
their care. If a peer review does not occur, whatever the reason may be, it is that clinician’s 
responsibility to address this. 




 


 

13. Glossary 

 

Abbreviation 

Definition 

# 

Fraction (i.e. Fractions of treatment) 

3DCT 

Three dimensional computed tomography (standard CT scan) 

CBCT 

Cone Beam computed tomography 

ChemoRT 

Chemotherapy with Radiotherapy 

CT 

Computed tomography 

CTV 

Clinical target volume 

DCIS 

Ductal carcinoma insitu 

EMRTN 

East Midlands Radiotherapy Network 

ESTRO 

European society for Radiotherapy and Oncology 

GTV 

Gross tumour volume 

Gy 

Gray (unit of measure for radiation dose) 

ICD 

Internal Cardiac device 

ICRU 

International commission on radiation units and measurements 

IMC 

Internal mammary chain 

IMN/IMLN 

Internal mammary nodes / Internal mammary lymph nodes 

IMRT 

Intensity modulated radiotherapy 

IR(ME)R 

Ionising Radiation (Medical Exposure) Regulations 

ITV 

Internal target volume 

LAD 

Left Anterior Descending Artery 

MDT 

Multi-disciplinary team 

MLC 

Multi lead collimator 

MRI 

Magnetic resonance imaging 

NACT 

Neo adjuvant chemotherapy 

NOG 

Network oversight group 

OAR 

Organs at risk 

PB 

Partial Breast 

PET (PET-CT) 

Positron emission tomography (Positron emission tomography – computed tomography) 

PRV 

Planning organ at risk volume 

PS 

Performance status 

PTV 

Planning target volume 

RCR 

Royal college of radiologists 

RT 

Radiotherapy 

SCF 

Supraclavicular fossa 

SGRT 

Surface Guided Radiotherapy 

SIB 

Simultaneous integrated boost 

 

 

U+E 

Urea and electrolytes 

VMAT 

Volumetric modulated arc therapy 

WB 

Whole breast 



 


 

14. References 

 

[1] 

 https://www.rcr.ac.uk/media/br2aqgpd/03-breast-cancer-radiotherapy-dose-fractionation-
fourth-edition.pdf 


[2] 

 https://jamanetwork.com/journals/oncology/articlepdf/2613411/jamaoncology_moran_2017_
oi_160109.pdf 


[3] 

 https://www.nice.org.uk/guidance/ng101/evnce/evidence-review-h-breast-radiotherapy-pdf-
4904666613 


[4] 

 https://www.rcr.ac.uk/sites/default/files/mgmt_cancer_patients_receiving_radiotherapy_cardiac_implanted_electronic_device_sep2015.pdf 


[5] 

 ESTRO consensus guideline on target volume delineation for elective radiation therapy of early 
stage breast cancer - Radiotherapy and Oncology (thegreenjournal.com) 


[6] 

 https://www.rcr.ac.uk/system/files/publication/field_publication_files/bfco21.pdf 


 

[7] 

 Bartelink H, Horiot J-C, Poortmans P, Struikmans H. Recurrence Rates after Treatment of Breast 
Cancer with Standard Radiotherapy with or without Additional Radiation. The New England 
Journal of Medicine 2001:10 


[8] 

 Yan M, Kong W, Kerr A, Brundage M. The radiation dose tolerance of the brachial plexus: A 
systematic review and meta-analysis. Clinical and Translational Radiation Oncology 2019;18:23–
31. https://doi.org/10.1016/j.ctro.2019.06.006. 


[9] 

 Ranger A, Dunlop A, Hutchinson K, Convery H, Maclennan MK, Chantler H, et al. A Dosimetric 
Comparison of Breast Radiotherapy Techniques to Treat Locoregional Lymph Nodes Including 
the Internal Mammary Chain. Clinical Oncology 2018;30:346–53. 
https://doi.org/10.1016/j.clon.2018.01.017. 


[10] 

 RCR. Prospective treatment of breast cancer: UK consensus. 2016. 


[11] 

 IMPORT High. IMPORT HIGH Planning_pack_version_4 0_final_23052013.pdf 2013. 


[12] 

 https://www.rcr.ac.uk/media/g2qg4yra/rcr-publications_postoperative-radiotherapy-for-
breast-cancer-hypofractionation-rcr-consensus-statements_may-2021.pdf 



 

 

[13] 

 https://www.icr.ac.uk/media/docs/default-source/default-document-library/fast-forward-
planning-pack.pdf?sfvrsn=b5052169_0 


[14] 

 Yaney, A. et al. (2021). Dosimetric parameters associated with radiation-induced esophagitis in 
breast cancer patients undergoing regional nodal irradiation. 155: 167-173 


[15] 

 Coles CE, Griffin CL, Kirby AM et al. Partial-breast radiotherapy after breast conservation surgery 
for patients with early breast cancer (UK IMPORT LOW trial): 5-year results from a multicentre, 
randomised, controlled, phase 3, non-inferiority trial. Lancet 2017; 390(10099): 1048–1060. 
doi:10.1016/S0140-6736(17)31145-5 


 [16] 

 https://www.thegreenjournal.com/article/S0167-8140(14)00524-6/fulltext 


[17] 

 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5454600/ 


[18] 

 https://www.redjournal.org/article/S0360-3016(22)00332-7/abstract 


[19] 

 https://www.rcr.ac.uk/media/z5jgmrhd/rcr-publications_the-timely-delivery-of-radical-
radiotherapy-guidelines-for-the-management-of-unscheduled-treatment-interruptions-4th-
edition_january-2019.pdf 


[20] 

 https://www.rcr.ac.uk/our-services/all-our-publications/clinical-oncology-
publications/postoperative-radiotherapy-for-breast-cancer-uk-consensus-statements/ 


[21] 

 NCCN Guidelines Version 3.2025 Invasive Breast Cancer, Page 15 


[22] 

 https://www.rcr.ac.uk/media/bpvngu2n/rcr-publications_radiotherapy-target-volume-
definition-and-peer-review-second-edition-rcr-guidance_october-2022.pdf