Radiotherapy breast

Breast Conservative Treatment
 Breast-conserving treatment is now clearly established as the
most acceptable standard of care for the majority of women
with early-stage invasive breast cancer.
 Stage I-IIB (±T3N0)
 Recommended technique : Wide local excision of the primary
tumor, preferably with clear margins, axillary lymph node
dissection, and breast irradiation (45 to 50 Gy), usually with a
boost (depending on tumor size and status of the surgical
margins)
Perez and Brady’s Principles and Practice of Radiation Oncology (sixth edition)

Ideal patient for BCT Contraindications
 Unicentric primary tumors
 <4 to 5 cm in diameter
 Collagen vascular disease
 Germline mutations that
predispose to breast cancer
 Positive margins
 Advanced disease
 Multicentric disease
 Pregnancy
 Prior radiation
Perhaps with the exception of the patients with persistently positive diffuse
margins or gross multicentric disease, where removal of clinically and
radiographically apparent disease would result in an unacceptable cosmetic
outcome, breast conserving therapy followed by radiation can be offered to
most women with early-stage breast cancer and may be offered to a high
percentage of women with advanced cancers following neoadjuvant chemo-
or hormonal therapy.

National Surgical Adjuvant Breast
and Bowel Project (NSABP) – B06
2002

Cumulative Incidence of a First Recurrence of Cancer in the Ipsilateral Breast
during 20 Years of Follow-up among 570 Women Treated with Lumpectomy
Alone and 567 Treated with Lumpectomy plus Breast Irradiation

Disease-free Survival (Panel A), Distant-Disease–free Survival (Panel B), and Overall
Survival (Panel C) among 589 Women Treated with Total Mastectomy, 634 Treated
with Lumpectomy Alone, and 628 Treated with Lumpectomy plus Irradiation

Conclusion
 Lumpectomy followed by breast irradiation continues to
be appropriate therapy for women with breast cancer,
provided that the margins of resected specimens are free
of tumor and an acceptable cosmetic result can be
obtained.

CALGB/ Canadian Trial/ SEER
Medicare analysis
 Radiation therapy was most likely to benefit those aged 70 to
79 years without comorbidity and was least likely to benefit
those aged 80 years or older with moderate to severe
comorbidity.
 Collectively, these studies indicate that the benefit of radiation
therapy for elderly women is significant in terms of local
control, but this absolute benefit is relatively small and must
be weighed against comorbidities and other competing risks.
 For women with favorable T1N0 receptor-positive breast
cancers, tamoxifen alone is a reasonable option that should be
discussed

Dose Schedules
 The standard radiation therapy schedule treatment delivers
1.8 to 2.0 Gy per day for 25 to 28 days for a total dose of 45 to
50.4 Gy followed by a 5 to 8 fraction boost (10 to 16 Gy) for a
total dose of 60 to 66 Gy delivered for 6 to 7.5 weeks.
 There has a been a growing trend toward hypofractionation,
which involves delivering a higher dose per fraction for a
shorter number of fractions for a biologically equivalent dose.
 This has been shown to be safe and effective as a standard
treatment schedule.

The UK Standardisation of Breast
Radiotherapy (START) Trial A
 Early breast cancer (pT1-3a pN0-1 M0)
 2236 patients randomized
 50 Gy in 25 fractions of 2.0 Gy
 41.6 Gy in 13 fractions of 3.2 Gy
 39 Gy in 13 fractions of 3.0 Gy over 5 weeks after surgery.
 Thus, the overall treatment time was kept constant in all three
arms

Results
 Median follow up : 5·1 years
 Local-regional tumour relapse at 5 years
 3·6% after 50 Gy
 3·5% after 41·6 Gy
 5·2% after 39 Gy
 Estimated absolute differences in 5-year local-regional
relapse rates compared with 50 Gy were 0·2% after 41·6
Gy and 0·9% after 39 Gy

CONCLUSION
 The authors concluded that a lower total dose in a
smaller number of fractions could offer similar rates of
tumor control as standard fractionation

UK START Trial B
 Early breast cancer (pT1-3a pN0-1 M0)
 2215 patients randomized
 50 Gy in 25 fractions of 2.0 Gy over 5 weeks
 40 Gy in 15 fractions of 2.67 Gy over 3 weeks

Results
 Median follow up = 6 years
 The rate of local-regional tumour relapse at 5 years was
 2·2% in the 40 Gy group
 3·3% in the 50 Gy group
 Absolute difference of –0·7% 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-assessments indicated lower
rates of late adverse eff ects after 40 Gy than after 50 Gy.

Conclusion
 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 standard
schedule of 50 Gy in 25 fractions.

Role of a 10-Gy boost in the
conservative treatment of early
breast cancer: results of a
randomized clinical trial in Lyon,
France.
P Romestaing, Y Lehingue, C Carrie, R Coquard, X Montbarbon, J M Ardiet, N Mamelle, J P Gérard

 1,024 women with early breast carcinoma
 Local excision, axillary dissection, and conventional 50-Gy
irradiation given in 20 fractions over 5 weeks
 Randomly assigned to receive either no further treatment
or a boost of 10 Gy by electrons to the tumor bed.
 The median follow-up time was 3.3 years

Results and Conclusion
 At 5 years, 10 patients of 521 who had received the boost
and 20 of 503 who had received no further treatment had
developed a local recurrence (P = .044)
 The boost group had a higher rate of grade 1 and 2
telangiectasia (12.4% v 5.9%)
 Delivery of a boost of 10 Gy to the tumor bed after 50 Gy
to the whole breast following limited surgery significantly
reduces the risk of early local recurrence, with no serious
deterioration in the cosmetic result.

CONCLUSION
 After a median follow-up period of 10.8 years, a boost
dose of 16 Gy led to improved local control in all age
groups, but no difference in survival.

TECHNIQUE FOR RADIOTHERAPY
 Positioning
 Immobilization
 Simulation
 Target Volume
 Treatment Planning
 Dose & Fractionation
 Set Up Verification
 Sequelae Of Radiotherapy

TREATMENT POSITION
• Most important aspect of positioning – patient comfort &
reproducibility.
•Supine
•Prone

Supine:
• Most patients are treated in the supine position, with the arm/s
abducted and faceturned to the C/L side
• Breast tilt boards with armrests used for positioning

Other treatment positions
Prone
• Requires patient to
climb onto a prone
board, lie on the
stomach & rest the
arms over the head.
• The i/l breast gravitates
through a hole in the
breast board & c/l breast
is pushed away against an
angled platform to avoid
the radiation beams

ADVANTAGES
SUPINE PRONE
Ease of set up Narrowing of breast shape makes gaining a
homogenous dose easier
Tried and tested technique that staff are
familiar with
Organs at risk may be separated from the
breast tissue leading to reductions in lung
volume
Can match nodal fields to chest wall fields
when required
Respiration while prone is limited reducing
intrafractional movement
A systematic review of methods to immobilise breast tissue during adjuvant breast
irradiation Sheffield Hallam University Research Archive

DISADVANTAGES
SUPINE PRONE
Immobilisation of breast tissue may be
difficult in women with large or
pendulous breasts with unknown effects
on subsequent cosmesis
PTV often doesn’t include the chest wall
which may be a problem depending on
the position of the original tumour.
Not possible to match nodal fields
A systematic review of methods to immobilise breast tissue during adjuvant breast irradiation
Sheffield Hallam University Research Archive

Breast Board
Breast board is an
inclined plane with fixed
angle positions
The ant. Chest wall
slopes downward from
mid chest to neck
Brings the chest
wall parallel to
treatment couch

Advantages of breast board
• Several adjustable features allow for the manipulation of patient’s
arms, wrists, head and shoulders.
• Makes chest wall surface horizontal.
• Brings arms out of the way of lateral beams.
• Thermoplastic breast support can be added for immobilization.
• Constructed of carbon fibre which has lower attenuation levels
permitting maximmum beam penetration.

Wing board
 Simpler positioning device
 Can be used in narrow bore
gantry
 Chest wall slope cannot be
corrected
 Need other techniques for
reducing dose to heart and field
matching

Immobilization devices
 Thermoplastic shells
 Adhesive tape
 Vac lock
 Alpha cradle
 Wireless bra
 Breast ring
 Breast cup
 Stocking
 Vacuum
 L-shaped breast plate

For large pendulous breast
• Patients with large or pendulous breasts treated supine
require a breast support, either with a thermoplastic shell, or
breast cup which can be used to bring the lateral and inferior
part of the breast anteriorly away from the heart, lung and
abdomen.

Breast ring with valecro
RING DEVICE
 The ring consists of a hollow PVC tube wrapped around the
base of the breast and supported by a Velcro strap

POSITION OF ARMS
 The preferred arm position is bilateral arms to be abducted 90
degrees or greater & externally rotated
 Arm elevation required to facilitate tangential fields across the
chest wall without irradiating the arm.
 Advantages of raising both arms vs only the I/L arm
 Patient is more comfortable and relaxed
 Position is more symmetrical and easily reproducible
with lesser chances of rotation of the torso
 More precise matching of the previously irradiated field
if c/l breast requires radiation infuture

Position of head:
Rigid head holder or a
neck rest can be used to
stabilize & position head
 Also elevate the chin to
minimize neck skin folds
Perez and Brady’s Principles and Practice of Radiation Oncology (sixth
edition)

Simulation
 CT scan : Standard for EBRT planning
 Scar and drain sites are marked with radiopaque markers
 Field borders are marked with radiopaque wires
 CT data are acquired superiorly from neck and inferiorly up to
diaphragm
 Slice thickness should be sufficient (usually 5 mm)

Technique
 Two tangential fields are used
 Additional fields for SCF, IMC nodes

Conventional Planning
 Upper margin : Head of the clavicle
 Medial margin :
 If no internal mammary portal is used, should be at or 1 cm over
the midline
 If an internal mammary field is used : the medial tangential
portal is located at the lateral margin of the internal mammary
field.
 Lateral-posterior margin : 2 cm beyond all palpable breast
tissue, which is usually near the midaxillary line
 Inferior margin : 2 to 3 cm below the inframammary fold

SCF field
 Upper border : thyrocricoid groove
 Medial border : at or 1cm across midline
 Lateral border: just medial to the humeral head,
insertion of deltoid muscle
 Lower border : matched with upper border of
tangential fields usually just below clavicle head

Internal Mammary Nodes
 The medial border of the tangential field is moved 3 to 5
cm across the midline to cover the internal mammary
nodes in the first three intercostal spaces
 SEPARATE IMC FIELD
 Medial border – midline
 Lateral border – 5-6cm from midline
 Superior border – lower border of clavicle
 Inferior border – at xiphoid or higher if 1st three ICS
covered

Alignment of the Tangential Beam
with the Chest Wall Contour
 Due to the obliquity of the anterior chest wall, the
tangential fields require collimation so as to reduce
the amount of lung irradiated.
 Can be done by
 Rotating Collimators
 Breast Board
 Multileaf Collimation

However in a collimated field,
junction matching between the
bitangential fields and the
anterior SCF field becomes
problematic resulting in
hot/cold spots.
The need for collimation can
be eliminated if the upper
torso is elevated so as to make
the chest wall horizontal.
This is done by Breast Board

Matching SCF & chest wall fields
 A hot spot caused by divergence of the tangential & the SCF
field at the junction
 This may result in severe match line fibrosis or even rib
fracture.
 The divergence of fields can be eliminated by
 Angling the foot of the treatment couch away from the radiation
 Collimator rotation
 Hanging block
 Half beam block

The Single Isocenter Technique for Matching Supraclavicular and
Tangential Fields
Single isocenter is set at the match between the supraclavicular and tangential fields.
The inferior portion of the beam is blocked for the supraclavicular treatment and the
superior blocked for the tangential field, with no movement of the isocenter, resulting
in an ideal match. Blocks are drawn as indicated to shield lung and heart. The field
should be viewed clinically to ensure that the blocks drawn to shield the heart and
lungs to not block target tissue on the breast–chest wall

Selection of appropriate energy
 X-ray energies of 4 to 6 MV are preferred
 If tangential field separation is >22 cm :significant dose
inhomogeneity in the breast
 So higher-energy photons (10 to 18 MV) can be used to deliver
a portion of the breast radiation (approximately 50%) as
determined with treatment planning to maintain the
inhomogeneity throughout the entire breast to between 93
and 105%.
 IMRT techniques such as field-in-field or dynamic multileaf
collimators (MLCs) may be utilized to reduce dose
inhomogeneity

Doses To Lung By Tangential Fields
 Usually up to 2 to 3 cm of underlying lung may be
included in the tangential portals
 CLD: perpendicular distance from the posterior tangential
field edge to the posterior part of the anterior chest wall
at the center of the field
 Radiation pneumonitis risk <2% with CLD<3 cm
CLD (cm) % of lung irradiated
1.5 cm 6%
2.5 cm 16%
3.5 cm 26%

Heart Dose
 When the CLD is >3 cm, in treatment of the left breast, a
significant volume of heart will also be irradiated
 Dose to heart can be minimized by
 Median tangential breast port
 Cardiac block & electron field
 Breath hold
 Gating

Localization of lumpectomy cavity
 The combination of surgical clips with a treatment
planning CT is most ideal.
 In the absence of surgical clips, CT scan of biopsy cavity or
postsurgical changes, in combination with clinical
information including mammography, scar location,
operative reports, and patient input, provide accurate
information regarding placement of the field and energy
of the electron boost

Electron Boost
 Approximate size of boost field = lumpectomy cavity + a
margin of 2 cm in all directions
 The accelerator head point straight down onto the target
volume
 90% isodose should cover tumor bed
 Usual range is 9 to 16 mev electrons
 Electron beam boost preferred because of
 Relative ease in setup
 Outpatient setting
 Lower cost
 Decreased time demands on the physician

Boost photon:
Mini tangential fields used to boost target volume
Interstitial boost:
1 or 2 planes of needles are usually needed to cover the
PTV depending upon size

Irradiation Dose to the Contralateral
Breast
 Concern due to potential long-term carcinogenic effect of
scattered radiation
 This risk appears to be minimal with modern techniques
 Use of tangential fields only resulted in more dose
delivered to the surface of the opposite breast, whereas
use of the internal mammary field in addition to the
tangential portals gave more dose deeper in the breast.

Following are helpful in decreasing
the dose to the contralateral breast
 Use of half-field blocks
 Independent jaws
 Use of MLCs
 Wedges on the lateral tangential fields rather than on the
medial
 2.5-cm-thick lead shield over the contralateral breast during
treatment with a medial tangential field
Perez and Brady’s Principles and Practice of
Radiation Oncology (sixth edition)

Breast CTV after lumpectomy
•Breast CTV: Includes all palpable breast tissue. Takes into
account clinical borders at the time of CT simulation. Limited
anteriorly within 5 mm from skin & posteriorly to the anterior
surface of the chest wall

 Breast PTV: Breast CTV + 7 mm expansion
 Breast PTV-EVAL: Clipped 5 mm into skin anteriorly and no
deeper than the anterior surface of the ribs posteriorly
(excludes bony thorax and lung)
 Lumpectomy GTV: Includes seroma and surgical clips when
present
 Lumpectomy CTV: GTV +1 cm margin
 Lumpectomy PTV: CTV+ 7 mm exclude heart

 Dosimetric advantages:
 Better dose homogeneity for whole breast RT
 Better coverage of tumor cavity
 Feasibility of SIB
 Decrease dose to the critical organs
 Left sided tumors- decrease heart dose
 Disadvantages:
 May increase the volume of tissue exposed to lower doses
of radiation.
 May increase the risk of second malignancies

IMRT advantages over
3DCRT:
•Improved conformity
dose to PTV
•Lower dose to most
OARs
IMRT disadvantages
over 3DCRT :
•Increased mean dose
to heart and
contralateral lung
•Higher integral dose

 Lymphedema and Breast Edema
 Skin and Breast Complications
 Brachial Plexopathy
 Pulmonary Sequelae
 Cardiac Sequelae
 Contralateral Breast Cancer and Irradiation
 Incidence of Other Second Malignancies
 Post irradiation Angiosarcoma of the Breast

Arm Lymphedema
 Risk of arm edema increases with axillary dissection and
RT
 Associated with swelling, weakness, limitation in range of
movement, stiffness pain & numbness
 Differentiate between treatment-associated
complications and tumor recurrence in regional
lymphatics
 Compression pump, along with skin care, exercise, and
compression garments

Pulmonary sequalae
 Rate of symptomatic pneumonitis 1-2% after WBRT
 Patients present with dry cough, shortness of breath, pleuritic chest pain
or fever and on radiographic studies a pulmonary infiltrate is observed in
the irradiated volume.
 Responds well to steroids
 The risk is related to
 Age>60 yrs
 Previous lung disease
 RT dose, fractionation
 Volume of lung irradiated.
 Regional nodal radiation therapy
 Concurrent chemo (taxanes)

Cardiac sequalae
 May be acute or chronic
 Pericarditis is acute transient but may be chronic
 Late injury includes CHF ,ischemia, CAD,MI
 Risk of cardiac toxicity greater in
 Left-sided breast cancers
 Patients receiving other cardiotoxic therapies, including
adriamycin, epirubicin, and trastuzumab.
 Old RT techniques
 IMC irradiation

Dose Constraints
Volume Segment End point Dose Rate
Lung -Whole Organ Symptomatic
Pneumonitis
V20≤30% <20
Mean dose = 13 10
Mean dose = 20 20
Heart - Pericardium Pericarditis Mean dose <26 <15
Whole organ Long term cardiac
mortality
V25<10% <1
Radiation Dose Constraints for Organs at Risk

Brachial Plexopathy
 Incidence:1-2%
 Possible complication of regional nodal radiation therapy
 Pain, loss of sensation, muscle weakness ,paralysis
muscles of the shoulder and upper limb
 Risk factors includes
 Axillary dose >50 Gy
 Concomitant chemotherapy
 Important to distinguish between metastatic and
radiation-induced brachial plexopathy.

Contralateral Breast Cancer
 Although all patients with a diagnosis of breast cancer are at
increased risk for developing a contralateral breast cancer, the
additional risk contributed by radiation treatment appears to
be minimal, with modern techniques
 EBCTCG 2005 overview analysis does suggest an elevated
incidence of contralateral breast cancer in patients receiving
radiation compared with those who did not receive radiation
(p=.002).
 Although the excess risk appears to be driven primarily by
older trials using antiquated techniques, these data highlight
the need to maintain dose to the contralateral breast as low as
possible.

Incidence of Other Second
Malignancies
 EBCTCG overview analysis did demonstrate an excess risk
of secondary cancers of the lung and esophagus as well as
leukemia and sarcoma in all randomized trials of breast
cancer that compared patients treated with and without
radiation
 The total relative risk for all secondary nonbreast
malignancies was 1.20 (± 0.06; P = .001).

Post Irradiation Angiosarcoma of
the Breast
 Rare but severe long-term
complication of patients
treated with radiotherapy
 Special attention should
be paid to uncommon skin
changes of the treated
breast
 The primary therapy is
simple mastectomy if wide
tumor-free margins can be
achieved

Radiotherapy breast

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