Contouring guidelines for breast cancer radiation therapy aim to define target volumes to adequately treat while minimizing toxicity. The RTOG and ESTRO guidelines provide consensus on contouring clinical target volumes (CTVs) for the breast/chest wall, lymph nodes, and organs at risk. However, some recurrences occur outside these guidelines. A study mapping 243 nodal recurrences found most were within RTOG or ESTRO CTVs, but out-of-field recurrences were often in the lateral and posterior supraclavicular region, particularly for young, triple-negative patients. While contouring guidelines provide standardization, individualized risk assessment may be needed to optimize local control versus toxicity.

1. Contouring in Breast
Cancer Current Practice
and Future Directions
Dr Anil Gupta
AIIMS, New Delhi

2. INDEX
• Need of RT Post BCS and Post Mastectomy
• Need of Contouring guidelines
• Various Contouring guidelines
• RTOG Contouring
• EORTC Contouring
• Controversies

3. Impact of RT after
BCS
EBCTCG meta analysis 2011
Breast Conservative Treatment = BCS + LR RT

4. Impact of Post
Mastectomy RT + RNI
EBCTCG meta analysis 2005
Radiotherapy produces its greatest absolute effects on local recurrence in
women who are at greatest risk of local recurrence. For, whether the
underlying risk is low or high, about 70% of it can be avoided by radiotherapy
No OS
benefit

5. Impact of Post
Mastectomy RT + RNI
EBCTCG meta analysis 2014
Addressed
treatment of
node 1-3
issue

6. Indications of
PMRT
• Tumor > 5 cm (>T3)
• Node Positive
• Positive margins

7. Need of Contouring guidelines
• RT has undergone transition from 2 D to 3 D
Planning
• Newer techniques- Better Conformality/ Lower
toxicity
• However, accurate identification of Clinical
Target Volume becomes necessary

8. • RTOG- expert consensus guidelines
• ESTRO- expert consensus guidelines
• RADCOMP- RTOG 3509/3510 studies-
randomized trial of proton therapy versus
photon therapy for breast cancer
• TROG 12.02 PET LABRADOR

9. CLINICAL ANATOMY

10. Deep relations of the breast
 Lies on deep
fascia/pectoral fascia
covering the pectoralis
major.
 Is separated from pectoral
fascia by loose areolar
tissue- retromammary
space.
 Clinical importance;- if
retromammary space
infiltrated. Fixity of breast

11. CT Anatomy
Pectoralis Major
Pectoralis Minor
Subscapularis
Axillary Vein

12. Glandular
tissue of
breast
Lattismus Dorsi m
Sternum
Scapula
Serratus anterior
Intercostal m

13. RTOG- Overlying
Principles
1. Before Planning CT- Clinical
breast/ Clinical Chest wall
should be marked by
radiopaque markers
2. Includes the apparent CT
glandular breast
3. Incorporates consensus
definitions of anatomical
borders
4. Includes lumpectomy CTV
5. Includes the mastectomy scar
(may not be feasible for occasional cases where
scar extends beyond the typical borders of chest
wall)

14. • Cranial
- Clinical Reference +
Second rib insertion
• Caudal
- Clinical reference + loss of
CT apparent breast
12/15/2019

15. • Posterior:
- Breast-Excludes
pectoralis muscles,
chestwall muscles, ribs
- Breast + Chestwall
(Stg>IIIA)- Includes
pectoralis muscles,
chestwall muscles, ribs
- Chestwall- Rib-pleural
interface. (Includes
pectoralis muscles,
chestwall muscles, ribs)
• Anterior:
- Skin

16. • Medial
- Sternal rib junction
• Lateral
- Clinical Reference + mid
axillary line typically,
excludes latissimus (Lat.)
dorsi m.
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17. • Cranial
- Residual breast-Upper border of
palpable/ visible breast tissue;
maximally up to the inferior
edge of the sternoclavicular joint
- Thoracic wall-Guided by
palpable/visible signs; if
appropriate guided by the
contralateral breast; maximally
up to the inferior edge of the
sterno-clavicular joint
• Caudal
- Residual breast-Most caudal CT
slice with visible breast
- Thoracic wall-Guided by
palpable/visible signs; if
appropriate guided by the
contralateral breast
ESTRO-Vessel based Contouring

18. • Posterior:
- the skin and subcutaneous
tissue to the anterior surface
of pectoralis major, and only
recommends inclusion of the
pectoralis muscles and ribs in
the setting of documented
invasion for T4a and T4c
tumors
(In contrast to RTOG which
covers pectoralis major and rib in
all cases)
• Anterior:
- 5 mm under skin surface

19. • Medial
- Lateral to the medial perforating
mammarian vessels; maximally
to the edge of the sternal bone
- Guided by palpable/visible signs;
if appropriate guided by the
contralateral breast
• Lateral
- Lateral breast fold; anterior to
the lateral thoracic artery
- Guided by palpable/visible signs;
if appropriate guided by the
contralateral breast. Usually
anterior to the mid-axillary line

20. Challengers

21. • 5 surgical case series with 278 patients with chest wall recurrence
• Deep Chest wall recurrences = 0

23. • Multi Institutional study of mapping local and regional recurrences
in patients treated between 2006 and 2014
• Only included patients with recurrences, No information on total
number and proportion of recurrences
• Patients treated with conventional field borders, with tangents,
SCF and ICF Level III and IMC
• Mapped these recurrences on contoured volumes of ESTRO and
RTOG
• The incidence and location of LRRs ‘‘outside ESTRO-, inside RTOG-
CTVs”, and ‘‘outside RTOG-CTV noted

24. Inside ESTRO CTV
Inside RTOG outside ESTRO CTV
Outside RTOG CTV
Local recurrences Regional recurrence in
the axillary & IMN
Regional recurrence in the
supraclavicular/infraclavicular
nodal area

25. • In BCC 96% LRR was inside ESTRO
• The rate of LR located outside the ESTRO-CTV but inside the
RTOG-CTV was 28.9% for mastectomy patients
• Sizable risks of geographic target misses were found in
mastectomy patients with a thin chest wall and in patients with
certain indicators of aggressive tumor behaviour, including young
age and triple negative tumors, as well as advanced stage
• Recurrence rate outside the ESTRO and RTOG-CTVs of the LN
supraclavicular was high (30%) and concentrated in the posterior
lateral side of the SCL fossa, more so in young age and TNBC

26. OAR toxicities

28. • Isolated recurrences deep to the pectoralis are uncommon,and
routine inclusion of the ribs and intercostal muscles in the chest
wall CTV might not be necessary for routine applications of
postmastectomy radiation therapy
• Inclusion of the ribs and intercostal muscles in the chest wall CTV
as recommended by the RTOG contouring guidelines significantly
increase the doses to the heart and lungs

29. Lumpectomy GTV
1. Include seroma cavity
2. Include all surgical clips when present
3. Use pre-operative imaging
4. Pre-operative and per-operative clinical findings
5. Architectural changes in planning CT
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30. Identifying seroma cavity
in open cavity surgery
Landis et al 2007

32. Identifying seroma cavity
in closed cavity surgery

33. Identifying seroma cavity
in closed cavity surgery
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33AIIMS ACADEMICS 2018

34. 12/15/2019
34AIIMS ACADEMICS 2018

35. Define delineation guidelines for the clinical target volume
(CTV) for PMRT in the immediate breast reconstruction (IBR)
implant/prosthesis based (IBR-i )and autologous IBR (IBR-a)

36. (A) retropectoral with full coverage by the pectoral muscle; (B) retro-pectoral
with partial coverage by the pectoral muscle and supportive material in the
lower part; (C) pre-pectoral with full coverage by supportive material
Implant positioning

37. Retropectoral- If the dorsal fascia of the breast is not
involved by cancer-
CTV ventral
Pectoralis Major
Implant
only subcutaneous lymphatic plexus to be
covered

38. Retropectoral with partial coverage
or rectropectoral with dorsal fascia involvement by cancer
CTV ventral
CTV dorsal
Pectoralis Major
Implant
lymphatic plexus should be irradiated as well as the part
of the chest wall that was initially not covered by the
pectoral muscles

39. Pre-pectoral implant
CTV ventral
CTV dorsal
Pectoralis Major
Implant

40. Regional Nodes
AXILLA
SCF
IMN

41. RT to
Supraclavicular
Region alone
• 1-2 Node +ve in SLNB with no
dissection
• Post BCS or MRM with 1-3 nodes
positive
• Clinical N2 OR N3 disease

42. Indications of RT to
Axilla + SCF
• Axilla N+ with extensive ECE
• SN+ with no dissection (1-2 SLNB
positive may be avoided)
• Inadequate axillary dissection
• High risk with no dissection
• Post BCS or MRM with ≥4 nodes
positive

43. Internal Mammary
Node Irradiation
• Individualized
• Consider for
• Central and medial lesions with high risk
• +SLN IN IMN chain
• +SLN in axilla with drainage to IMN on
scintigraphy
• Stage III breast cancer
• Positive Axillary nodes

44.  Level I- lymph nodes
lateral to lateral border of
pectoralis minor
 Level II- lymph nodes
between medial and
lateral borders of
pectoralis minor and
interpectoral lymph nodes.
 Lymph III- nodes medial to
medial margin of
pectoralis minor
Axillary Lymph Nodes (Surgical Anatomy)

45. Other groups of lymph nodes
 Internal mammary lymph
nodes- in the intercostal
spaces along the edge of
the sternum.
 Supraclavicular lymph
nodes- in the
supraclavicular fossa
 Intramammary lymph
nodes- within the breast
are considered as axillary
LNs for staging.

46. 12/15/2019
Axillary Vessels

47. 12/15/2019
47AIIMS ACADEMICS 2018
Deltoid M

48. RTOG- Nodal
Contouring
Supraclavicular
• Cranial - Caudal to the cricoid
cartilage
• Caudal- Junction of brachioceph.-
axillary vns./ caudal edge clavicle
head
• Anterior- Sternocleido mastoid
(SCM) muscle
• Posterior- Anterior aspect of the
scalene m.
• Lateral- Cranial: lateral edge of SCM
m. Caudal: junction 1st rib-clavicle
• Medial- Excludes thyroid and
trachea

49. Axilla Level I
• Cranial-Axillary vessels cross lateral
edge of Pec. Minor m.
• Caudal- Pectoralis (Pec.) major
muscle insert into ribs
• Anterior- Plane defined by: anterior
surface of Pec. Maj. m. and Lat.
Dorsi m
• Posterior- Anterior surface of sub
scapularis m.
• Lateral- Medial border of lat. dorsi
m.
• Medial- Lateral border of Pec.
minor m

50. Axilla level II
• Cranial- Axillary vessels cross
medial edge of Pec. Minor m.
• Caudal- Axillary vessels cross lateral
edge of Pec. Minor m
• Anterior- Anterior surface Pec.
Minor m.
• Posterior- Ribs and intercostal
muscles
• Lateral- Lateral border of Pec.
Minor m.
• Medial- Medial border of Pec.
Minor m.

51. Axilla level III
• Cranial- Pec. Minor m. insert on
cricoid
• Caudal- Axillary vessels cross
medial edge of Pec. Minor m
• Anterior- Posterior surface Pec.
Major m
• Posterior- Ribs and intercostal
muscles
• Lateral- Medial border of Pec.
Minor m.
• Medial- Thoracic inlet

52. Internal mammary nodes
• Encompass the internal mammary/
thoracic vessels
• Cranial- Superior aspect of the
medial 1st rib
• Caudal- Cranial aspect of the 4th rib

53. EORTC- Vessel Based Contouring
• Lymph node level 4 (same as
Supraclavicular)
• Cranial - Includes the cranial extent of the
subclavian artery (i.e. 5 mm cranial of
subclavian vein)
• Caudal- Includes the subclavian vein with
5 mm margin, thus connecting to the
cranial border of CTVn_IMN
• Anterior- Sternocleidomastoid muscle,
dorsal edge of the clavicle pleura
• Posterior- Including the jugular vein
without margin; excluding the thyroid
gland and the common carotid artery
• Lateral- Cranial: lateral edge of SCM m.
Caudal: junction 1st rib-clavicle
• Medial- Includes the anterior scalene
muscles and connects to the medial
border of CTVn_L3

54. Axilla Level I
• Cranial- Medial: 5 mm cranial to the
axillary vein Lateral: max up to 1 cm
below the edge of the humeral head, 5
mm around the axillary vein
• Caudal- To the level of rib 4 – 5, taking
also into account the visible effects of the
sentinel lymph node biopsy
• Anterior- Pectoralis major & minor
muscles
• Posterior- Cranially up to the thoraco-
dorsal vessels, and more caudally up to an
imaginary line between the anterior edge
of the latissimus dorsi muscle and the
intercostal muscle.
• Lateral- Cranially up to an imaginary line
between the major pectoral and deltoid
muscles
• Medial-

55. Axilla level II
• Cranial- Includes the cranial extent
of the axillary artery (i.e. 5 mm
cranial of axillary vein).
• Caudal- The caudal border of the
minor pectoral muscle
• Anterior- Anterior surface Pec.
Minor m.
• Posterior- Ribs and intercostal
muscles
• Lateral- Lateral edge of minor
pectoral muscle
• Medial- Medial edge of minor
pectoral muscle

56. Axilla level III
• Cranial- Includes the cranial extent of
the subclavian artery (i.e. 5 mm cranial
of subclavian vein)
• Caudal- 5 mm caudal to the subclavian
vein. If appropriate: top of surgical ALND
• Anterior- Major pectoral muscle
• Posterior- Up to 5 mm dorsal of
subclavian vein or to costae and
intercostal muscles
• Lateral- Medial side of the minor
pectoral muscle
• Medial- Junction of subclavian and
internal jugular veins – >level 4

57. Internal mammary node
• Caudal limit of CTVn_L4
• Cranial side of the 4th rib

58. Nodal Recurrence Mapping

59. • The primary goal was to map the anatomic pattern of
isolated nodal recurrences (NR) in the supraclavicular (SCV),
axillary, and internal mammary nodes (IMNs) in patients with
breast cancer treated with curative-intent surgery with or
without radiation therapy (RT)

60. • Patients with NR after treatment at a single cancer center
during 1998 to 2013 were identified
• All NRs were overlaid onto representative axial computed
tomographic images
• The locations of 243 NRs among 153 eligible patients were
mapped

61. Results
• NRs were confirmed by pathology in 73%
• The majority of NR occurred in the axilla (42%; 102/243)
• IMN (32.5%; 79/ 243)
• SCV (25.5%; 62/243)
• Radiation Therapy Oncology Group (RTOG) or European
Society for Radiation therapy and Oncology (ESTRO) clinical
target volume encompassed 82% (198/243) of NRs
• The majority of out-of-field NRs were located in the lateral
and posterior SCV region for both RTOG (67%; 30/45) and
ESTRO (89%; 49/55) guidelines.

62. • Specifically, the RTOG-CTV group included 82% (198/234) and
the ESTRO-CTV group included 77% (188/234) of the NRs
• The SCV group harbored the bulk of out-of-field recurrences
from both RTOG (missing 48% or 30/62 of SCV recurrences)
and ESTRO (missing 79% or 49/ 62 of SCV recurrences)
guidelines, followed by the IMN (2.5%; 2/79 for both) and
axilla (13% or 13/102 for RTOG, and 1% for ESTRO)

65. • To investigate incidence and location of locoregional
recurrence (LRR) in patients who have received postoperative
locoregional radiotherapy (LRRT) for primary breast cancer
• Medical records were reviewed for all patients who received
postoperative LRRT for primary BC in southwestern Sweden
from 2004-2008 (N=923)
• Patients with LRR as a first event were identified (N=57)

67. Conclusions
• Deep Chest wall recurrences are uncommon
and routine inclusion of it in target volume leads
to higher lung and cardiac toxicities
• There is geographical miss in posterior and
lateral supraclavicular region
• These evidences should be addressed in expert
based consensus guidelines