Breast Flashcards
Supraclav borders
Cranial: Cricoid Caudal: Caudal edge of clavicle Anterior: SCM Posterior: Scalene Muscle Lateral: lateral SCM Medial: Thyroid/Trachea
Axillary lvl III borders
Cranial: Coracoid Process Caudal: Ax vessels cross medial edge of Pec Min Anterior: Pec Major Posterior: Ribs Lateral: Medial edge Pec Minor Medial: Thoracic Inlet
TNM
Tis: DCIS, LCIS, pagets
T1mic: ≤ 1mm T1a: 1-5 mm T1b: > 5-10 mm T1c: > 10-20 mm T2: > 2-5 cm T3: > 5 cm T4: T4a: chest wall not including pec T4b: •skin •edema •ulceration •skin nodules or peau d’orange T4c: T4a and b T4d: inflammatory
cN1: moveable cN2a: fixed cN2b: IMN only cN3a: infraclav (III) cN3b: IMN and axilla cN3c: supraclav
cM0(i+) – circulating metastatic tumor cells in blood or found in other tissue < 0.2mm
pN stage
pN1mi: >0.2-2mm or >200 cells pN1a: 1-3 ax nodes (one >2mm) pN1b: IM by SLN bx pN1c: both N1a + N1b pN2a: 4-9 nodes pN2b: clin IMN only pN3a: >10 or infraclav pN3b: clin IMN + ax; or IM by SLN + >3 ax pN3c: supraclav
ITC: < 0.2 mm; behave like pN0
NEVER N2c in breast
Overall Stage
IA: T1N0 IB: T1N1mi IIA: T1N1, T2N0 IIB: T2N1, T3N0 IIIA: T3N1, N2 IIIB: T4 IIIC: N3
ASTRO PBI consensus guidelines:
ASTRO PBI consensus guidelines: Suitable: ->50 y/o --- -Tis/T1 only (≤ 2cm) -Marg >2mm -pN0 --- -DCIS <2.5cm, gr1-2, >3mm margins
Cautionary:
- 40-49yo
- 50+ if one path criteria
- –
- T2
- Invasive lobular
- ER-
- Focal LVSI
- Close margins
- –
- Pure DCIS < 3 cm
Unsuitable:
- Age <40
- BRCA positive
- –
- T3, T4
- Multicentric/focal
- Extensive LVSI
- Margins +
- pN+ or NX
Hormonal therapy
Hormonal therapy
SERM: premenopausal
- Tamoxifen 20mg po qd x 5 yrs
- Can also consider Lupron + AI
Tam: (HATE) – less in younger individuals Hot flashes VAginal bleeding Thomboembolic Endometrial ca
AI: postmenopausal
- Blocks androgen to estrone+ estradiol
- Nonsteroidal: Letrozole 2.5mg, Anastrozole 1mg
- Steroidal: Exemestane
Arimidex/AI (post-meno): osteoporosis, thromboembolic (lower than TAM), endometrial cancer (lower than TAM)
DCIS Managment
1) Lumpectomy (wire-localized) -> specimen mammo (post-excision mammo if clip not in specimen) -> XRT + boost -> tam for 5-10 yrs for ER+
•Boost – retro data, extrapolate from IDC
•More important in: young, high grade, close margin
2) Simple mast -> tam for 5 yrs for ER+
* *(if widespread or pt choice)**
- should do SLNB (can’t go back to do if invasive disease found)
*if find invasive cancer at DCIS surgery -> get ER/PR/Her2, do SLNBx
Omit Boost
- Age>70
- HR+
- Grade 1-2, >2 mm margins
BCT: contraindications:
- Pregnancy
- Multicentric (>1 quadrant)
- Persistent + margins
- Diffuse microcalcs
Early IDC management BCS
1) Lumpectomy + SLNB -> Chemo if indicated -> XRT -> hormone tx if indicated
42. 5/16 + 10 Gy boost (12.5 Gy if + margins)
=> definitely do boost for age <=50, or age 51-70 w/ high grade or positive margins
Early IDC management BCS: + SLNBx
For + SLNB, can omit ALND if ALL met: •T1-2, cN0 •<= 2 positive SLN, not matted, no ECE •No neoadj chemo administered •BCT w/ whole breast RT planned
or
N1mi only
APBI dose and quick WBRT
4) APBI dose
3.4 Gy bid x 10 (brachy)
30 Gy in 5 fractions QOD (external beam)
28.5 in 5 fractions weekly
Indications for adjuvant Chemo:
Indications for Chemo:
(1) Node positive even N1mi -> oncotype for post menopausal to decide if pN1: 1-3
(2) Triple negative > 0.5 cm
(3) Her2 positive > 0.5 cm consider for <0.5 if HR-
(4) Oncotype score >=26 (>=16 for premenopausal)
Pre-op chemo
Her2/TNBC T1c+ (>1cm) definitely for T2+
N+
inoperable
large tumor desiring BCS
Volumes and treatment design
Breast CTV= breast tissue, extends to ant surface of pec posteriorly then cropped 5 mm from skin (pec and serratous excluded from CTV)
Breast PTV= breast CTV +7mm
Breast PTV_eval = PTV cropped 5mm from skin and at anterior ribs (includes muscle)
“I would set the medial tangent first rotating the gantry to making sure the volumes are covered and minimizing heart, lung and contralateral breast dose. I would rotate the collimator to align with the chest wall. Apply a couch kick away from the gantry to allow for alignment of the superior edge of the field. I would then set the lateral tangent aligned to the medial field with a non-divergent deep field border”
- Borders: generally top of field is at level of axillary vessels (used to be humeral head) inferior clavicular head; flash 2 cm of breast; medial inside chest wall <2cm of lung; inferior 1.5-2 cm flash
- limit hot spot to < 110% (<107% if hypofx), 115% if 3rd field. Use field in field (also beam weigthing, changing calc point, change energy; wedge is last resort)
- isocenter set centrally at midline and mid axilla – shifted to within breast for treatment
- normalization/calc point 0.5 cm anterior to lung/breast interface
- prescription vs. normalization/calc pt – 1.5 cm
RNI sim and setup
Supine slant board, arm up, chin up and away. Markers.
I would plan to use a dual isocenter technique.
I would contour the nodal levels, OARs, and matchline at the clavicular head. Start the set up with the SCL field iso along the match line to allow for half beam block. laterally at the coracoid process if good dissection, lat humeral head if not or ECE, med vertebral pedicals with field angled 10-15 to reduce divergence into cord.
I would then setup the tangents with a z shift on the iso, I would start with the medial field with the gantry rotated to allow for target coverage and minimizing dose to OARs. Collimator aligned to the chest wall. Couch kick would be applied AWAY from the gantry to align with the SCL field. Medial tangent would then be placed matching posterior divergence.
Supraclav + level III: (50/2 Gy or 45 Gy)
- monoisocentric technique
- same pt set-up, tilt chin away
- set SC field first: sup cricoid (or top 1st rib), inf clavicular head, lat coracoid process if good dissection, lat humeral head if not or ECE (block 2/3 of humeral head and AC joint), med vertebral pedicals with field angled 10-15 to reduce divergence into cord
- half beam block caudal edge of SCV field and cranial edge of tangents
- set tangent fields
- rotate gantry to align deep borders of tangent fields – with MI, can rotate gantry but NOT collimators! Means you have to use MLCs to block heart, etc
- if breast is too large (tangents > 20 cm – thus 40 cm total), can try dual isocenter technique. Half beam block SCV but not tangents, then kick couch AWAY from gantry to match divergence of tangents to SCV field. Can rotate collimators. Place iso at CW/lung interface.
- R breast = LAO
IMN:
1) partially wide tangents if favorable anatomy; not too much heart and lung (if lung dose too high electron match)
PAB: (0.4-0.5 Gy daily)
- used to supplement levels I-II
- use for ECE, 10/10+ nodes, gross disease, or inadequate dissection
- prescribed to midplane of axilla
- borders: inf matched to tangent, sup parallel to clavicle (diagonal), medial just inside chest wall, lateral humeral head.
- in modern practice, I would contour my nodes that need coverage. If adequate nodal coverage isn’t obtained with tangents, I would consider adding a posterior field
Breast constraints
Ipsi lung: V20 < 15% High tangent V20< 20% 3-field V20 < 35%
Heart:
V20 < 5%
mean < 4 Gy (per RCTs, ALARA, try <1-2 Gy)
For every increase of 1 Gy on mean heart dose, risk of CVD increases by 7%
Contralat lung V5 < 10%
Contralateral breast
Max 3 Gy
95% PTV gets 95% dose
V100%< 30%
hotspots under 10%
(less than 115 in SCV)
Electrons – don’t want more than 12mEV
Tamoxifen reduces contralateral breast cancer by 1/2
Indications for PMRT
N+, Stage III
consider for T3N0 and <1mm margins especially with another risk factor:
a. Premenopausal
b. LVSI
c. High grade
d. Triple negative tumor
e. Her2+ tumor
f. Extracapsular extension
h. T4
k. Genomic assay (oncotype or higher) – intermediate or higher
RNI for most
+ margins -> re-excision if not possible CW+RNI
Level I/II intentional nodal coverage
1. Gross undissected nodal disease (100% of prescribed dose) 2. Extracapsular extension 3. > 20% of lymph nodes removed are positive for cancer 4. at least 1 positive lymph node but < 10 lymph nodes removed
Inflammatory managment
Neoadj chemo -> MRM -> PMRT
-If no response to chemo, consider switching chemo, or pre-op RT (50 Gy with bolus every third day)
If PR or NR, 51 GY at 1.5 Gy BID followed by boost of 15 Gy BID at 1.5Gy Bid, total of 66 Gy then (5mm bolus x 15 fractions, more if no erythema)
If CR, then 50 Gy at 2 Gy per fxn, followed by 10 Gy boost at 2 Gy per fxn (5mm bolus x 15 fractions, more if no erythema):
Chemotherapy
Chemotherapy:
N+: AC-> T (or TC if frail, elderly, cardiac history)
- dd AC (every 2 weeks), dd paclitaxel q2weeks, or weekly
N-, ER+/HER2-:
Tumor <0.5 cm (T1a): endocrine therapy alone
Tumor >0.5 cm (≥T1b): Get Oncotype DX and AC chemo if high
– 21-gene assay yields a recurrence score, which relates to 10-yr risk of systemic recurrence with Tamoxifen alone
– If <50 yo 16+ -> chemo
• 26+ -> chemo
N-, -/-/-:
Tumor >0.6-1.0cm (i.e. T1b): Consider chemotherapy
Tumor >1 cm (≥T1c): Chemotherapy (usually AC then T)
HER2+:
Tumor >0.6-1.0cm (i.e. T1b): Consider multiagent chemo with Herceptin
Tumor >1 cm (≥T1c) or N+: Multiagent chemo with Herceptin (usually TCH)
ddAC x 4 ->ddTaxol x 4
- doxorubicin 60mg/m2 d1
- cyclophosphamide 600mg/m2 d1 q2wks x 4
- then paclitaxel 175mg/m2 q2weeks x 4
Herceptin (Trastuzumab)
– Begin Herceptin with Taxol
– 4 mg/kg loading dose 2 mg/kg weekly x1 y –OR- 6 mg/kg q3wks after Taxol
– Can give RT with Herceptin
– Cardiac monitoring at baseline, months 3, 6, 9 (4% risk of CHF)
Or THCP for Her2+ - docetaxel, carboplatin, Herceptin, pertuzumab – only done NACT
ACTH or Adria, Cycophos, Paclitaxel, Herceptin, Pertuzumab – can do NA alone
