Radiotherapy in carcinoma breast,interstial brachytherapy in carcinoma breast,indications of radiotherapy in carcinoma breast

1. RADIOTHERAPY IN
CARCINOMA BREAST
DR SAILENDRA
SENIOR RESIDENT
DEPT OF RADIOTHERAPY
MAULANA AZAD MEDICAL COLLEGE

2. INTRODUCTION
• Breast cancer is one of the most common cancers
seen and treated by radiation oncologists.
• Radiation plays an important role in the
management of breast cancer at all stages
including ductal carcinoma in situ, early-stage
disease (as a component of breast conservation),
and locally advanced disease (as an adjuvant
treatment after mastectomy).
• Radiation is also a highly effective palliative
modality.

3. RATIONALE
• MOST COMMON SITE OF RECURRENCE IS THE
LOCAL SITE
• PREVENTING RECURRENCE ALSO IMPROVES
THE QUALITY OF LIFE AND OVERALL SURVIVAL
• NOT ALL RECURRENCES ARE SALVAGEABLE

4. WHEN TO GIVE RT
• POST BCS
• POST MASTECTOMY
• PALLIATIVE
• NEOADJUVANT

5. Indiacations of whole breast
radiotherapy
• Tumour size >5cm
• Node positive
• All cases of BCS
• Positive or Close margin
Can be considered in high risk cases(not proved in prospective
randomised trials)
• High grade
• Young
• LVSI
• Inadequate nodal dissection
• Tripple negative receptor status
• Her-2 positive tumours
• Skin,nipple or pectoralis muscle invasion

6. Indications of axillary nodal irradiation
• N+ with extensive ECE
• SLN+ with no dissection
• Inadequate axillary dissection
• High risk with no dissection
High risk is defined as estimated probability of nodal involvement greater than 10% to 15%

7. Indications of SCLN irradiation
• Clinical N2 or N3 disease
• >4 +LN after axillary dissection
• 1–3 +LN with high risk features
• Node + sentinel lymph node with no dissection unless
risk of additional axillary disease is very small
• High risk no dissection
• The impact of supraclavicular RT on overall outcome
has never been examined in any randomised trial
separately from IMN RT.

8. Indications of IMN irradiation
• Internal mammary node (IMN) metastases
• 5%----negative axillary nodes
• 20% to 50%-----with positive nodes.
• Clinical IMN recurrence occurs in 1% or fewer patients
in nearly all studies
• Positive axillary nodes with central and medial lesions
• Stage III breast cancer
• +SLN in the IM chain
• +SLN in axilla with drainage to IM on
lymphosintigraphy
• Clinically positive IMLN

9. TECHNIQUE FOR RADIOTHERAPY
• Positioning
• Immobilization
• Simulation
• Target Volume
• Treatment Planning
• Dose & Fractionation
• Set Up Verification and treatment delivery

10. PATIENT POSITIONING AND
IMMOBILISATION
• Positioning & Immobilization most crucial
parts of RT treatment for
– accurate delivery of a prescribed radiation dose
– sparing surrounding critical tissues
• Primary goal:
– Reproducibility of position
– reduce positioning errors
– can reduce time for daily set up

11. PATIENT POSITIONING AND
IMMOBILISATION
• Supine or prone position
• Arms abducted and externally rotated to 90 or 120
degree.
• Prone position is Suitable for pendulous breasts, where
breast-only RT is required.
• Results in significantly better coverage of the breast
and significant reduction of dose to the ipsilateral lung
and heart.
• Decreases the skin toxicity due to loss of skin folding.
• PRONE POSITION HAS CERTAIN LIMITATIONS

13. Immobilisation devices
• Breast board
• Wing board
• Prone breast board

14. CARBON FIBRE
CHEST WALL HORIZONTAL
ARMS OUT OF BEAM PATH
CAN USE ORFIT

15. Simpler positioning device
Can be used in narrow bore
gantry
Chest wall slope cannot be
corrected

16. IMMOBILISATION DEVICES
• Thermoplastic shells
• Adhesive tape
• Vac lock
• Alpha cradle
• Wireless bra
• Breast ring
• Breast cup
• Stocking

17. V

18. SIMULATION
• Where available, CT simulator has become standard for
planning breast radiotherapy.
• Conventional simulator are also used
• Scar & drain sites identified with radiopaque markers.
• field borders are chosen & radiopaque wires are placed
• Radiopaque wires is also placed encircling breast tissue
• CT data are acquired superiorly from neck and
inferiorly up to diaphragm
• Slice thickness should be sufficient (usually 5 mm)

19. TARGET VOLUME
• AFTER BCS
– Whole breast radiotherapy + lumpectomy boost
– Regional nodes
• AFTER MASTECTOMY
– chest wall
– mastectomy scar
– regional nodes

20. CONVENTIONAL
TREATMENT
BORDERS

21. TANGENTIAL FIELD BORDERS
INFERIOR
– 1-cm margin inferiorly to the inframammary fold
SUPERIOR
– inferior edge of the sternoclavicular junction
Lateral
– Include all breast tissue with a 1-cm margin; this usually places this
border at the posterior to midaxillary line.
Medial
– At the midline in most patients.3cm lateral if IMN to be treated
Anterior
– 2cm margin of light is given above the highest point of the breast.
Posterior
– The deep edges of the tangents should be coincident

22. Deciding the gantry angle
• Lead wire placed on lateral border
• Field opened at 0⁰ rotation on chest wall and
central axis placed along medial border of
marked field
• Gantry rotated , until on fluoroscopy, central
axis & lead wire intersect – angle of gantry at
that point is noted – medial tangent angle
• Lateral tangential angle is 180 °opposite to
medial tangent

23. Things to ensure
• Ensure entire breast is covered
in portal.
• Margin of 1.5-2 cms beyond
the breast for respiratory
excursion
• 1 to 3 cm of lung visible on the
simulation film in the field
anterior to the posterior field
edge.
• The lead wire coincides with
the posterior edge of the
portal.

24. SUPRACLAVICULAR AND AXILLARY
FIELD
• Inferior
– Determined by the match-line with the tangential fields.
• Superior
– Radiologically, usually the superior-most portion of the first rib. it is
preferable not to clear skin(or “flash”) in the supraclavicular region.
• Lateral
– Usually medial two thirds of the humeral head. In some patients with
extensive axillary disease, it may be necessary to clear skin laterally.
• Medial
– Set up to the center of the suprasternal notch (midline),then angle the
gantry.
• Blocks
– lateral third of the humeral head should be blocked

26. INTERNAL MAMMARY FIELD
• Wide tangential field
• Direct IMN field
• Either by electron or both photon and
electron

28. DIRECT IMN FIELD
• Medial border
– Midline
• Lateral border
– 5-6cm from midline
• Superior border
– inferior border of SCF lower border of clavicle
• Inferior border
– at xiphoid or higher if 1st three ICS covered
• Depth
– 4-5 cm or as calculated radiologically

29. Matching of fields

30. POSTERIOR AXILLARY BOOST (PAB)
• Inferior:
– Block the field to match the superior border of the
tangential fields.
• Superior:
– Parallel the clavicle.
• Medial:
– 2 cm into the lung tissue medial to the chest wall.
• Lateral:
– At the middle of the humeral head.

31. Beam modification devices used in
planning of ca breast
• Wedge filters
• Bolus
• Tissue compensators

32. Wedge filters
• Wedges Are Used As
Compensators In Breast
Radiotherapy.
• Dose uniformity within
the breast tissue can be
improved
• Preferred in the lateral
tangential field than the
medial.

34. CONFORMAL RADIOTHERAPY

36. Breast CTV after BCS

37. Chest wall CTV after mastectomy

39. Supraclavicular and axillary CTV

40. Internal mammary node CTV

41. Beam energy
• X-ray energies of 4 to 6 MV are preferred
• Photon energies >6 MV underdose superficial
tissues beneath the skin surface
• 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 maintain the inhomogeneity throughout
the entire breast to between 93 and 105%

42. Dose of radiation
• Whole breast radiotherapy/chest wall irradiation
– Conventional Dose
• 50 Gy in 25 daily fractions given in 5 weeks
– Hypofractionated dose schedule
• 40 Gy in 15 daily fractions of 2.67 Gy given in 3 weeks.
• 42.5 Gy in 16 daily fractions of 2.66 Gy given in 3.5 weeks.
• Breast boost irradiation to Tumour bed
– 16 Gy in 8 daily fractions given in 1.5 weeks
– 10 Gy in 5 daily fractions given in 1 week
• Lymph node irradiation
– 50 Gy in 25 daily fractions given in 5 weeks
– 40 Gy in 15 daily fractions of 2.67 Gy given in 3 weeks.
Palliative dose schedule- 30Gy/10#,8Gy/1#

44. ROLE OF BOOST
Boost to Tumor Site after WBRT in BCS
RATIONALE :
• Local recurrences tend to be primarily in and
around the primary tumor site
• boost decreases risk of marginal recurrence.
• More advantageous when margins unknown
& young women less than 40 yrs but benefit
seen in all age group

45. Localization of lumpectomy cavity
Various techniques of localizing the tumour bed
include:
• CT scan
• MRI
• USG
• pre op MMG
• Surgical scar

46. METHODS OF BOOST
• EBRT
– PHOTON
– ELECTRON
• BRACHYTHERAPY
– INTERSTITIAL
– INTRACAVITARY(MAMMOSITE)

47. ELECTRON BOOST
• The patient is positioned with the arm toward the head
to flatten the breast contour
• the accelerator head can point straight down onto the
target volume.
• An electron energy of 9 to 16 MeV is usually used
depending upon the depth of cavity
• The 90% prescription isodose line is limited to the
chest wall to decrease dose to the lung.
• Target volume is lumpectomy cavity + 2cm margin on
all sides
• DOSE
– 10-20Gy with 2Gy/#

48. The margins of this field are marked on the skin with
the centre of the scar as the centre of field

49. Interstitial brachytherapy

50. • A number of needles or tubes are placed across the tumor
bed usually in 1-2 planes
• usually under general anesthetic,either using a template or
freehand
• Needles are placed parallel and equidistance from each
other
• In most cases inserted in mediolateral direction
• In very medially or laterally located tumours needles can be
inserted in craniocaudal direction also.
• The treatment volume is generally the tumor cavity plus a
1- to 2-cm margin.
• The dose can be delivered using LDR or PDR or HDR
brachytherapy,typically over 4 to 5 days.

51. ELECTRON BOOST IS PREFERED
• Relative ease in setup
• Outpatient setting
• Lower cost
• Decreased time demands on the physician,
• Excellent results compared with 192Ir
implants

53. ACCELERATED PARTIAL BREAST IRRADIATION
PARRIAL BREAST IRRADIATION
PARTIAL BREAST IRRADIATION
The target volume irradiated is only
the post lumpectomy tumor bed with
1-2cm margin around
ACCELERATED DOSE DELIVERY
• The dose is delivered in a shorter
interval than the standard 5 – 6 weeks
• Treatments delivered twice daily (with
treatments separated by six hours) for
10 treatments delivered in 5
treatment days(34Gy/10#)

54. RATIONALE OF APBI
• Most breast cancer recurrences occur in the index
quadrant
• Many patients cannot come for prolonged 5-6 week
adjuvant radiotherapy for logistic reasons
• Reduces overall treatment period considerably
• Patient convenience may increase acceptance of
radiation treatment after breast- conservation surgery

55. ASTRO APBI GUIDELINE

57. MODALITIES OF APBI
• HDR interstitial brachytherapy
• Intracavitary brachytherapy :Mammosite
• 3DCRT/IMRT
• Intra-operative electrons (ELIOT)
• Orthovoltage X rays (TARGIT)

58. Benefits
• Larger dose can be delivered to small area
• Limited radiation exposure to normal tissue
• Treatments completed in one week instead of six
weeks
Limitations
• May require additional surgical procedure
• Requires twice daily treatment
• Newer modality with far fewer patients treated
and much shorter follow-up

59. • Although the early results clearly demonstrate
the feasibility and acceptable toxicity of
accelerated partial breast irradiation, this
approach has not yet been demonstrated in a
randomized trial to be equivalent to whole
breast irradiation.

60. COMPLICATIONS OF RADIOTHERAPY
• 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

61. SEQUENCING OF RADIOTHERAPY
• Usually chemotherapy followed by
radiotherapy
• In margin + or close margin(2mm)-
radiotherapy is considered first followed by
chemotherapy
• Hormon therapy to be started after
completion of radiotherapy

62. TRIALS PROOVING ROLE OF RT IN BCS

63. TRIALS PROOVING ROLE OF PMRT

64. Take home message
• RT improves local control as well as overall
survival in carcinoma breast.
• RT is mandatory in post BCS patients
• Hypofractionation in breast cancer is possible and
can be practised
• Boost though increases local control,there is
compromise in cosmesis,so it’s a debatable issue.
• IMRT is prefered over 3DCRT AND conventional
technique.

65. Thank you