RadOnc Resident Wiki/Breast/Breast overview

Clinically node negative
Or T3N1, No T4

Options: For systemic adjuvant therapy see below, chemo comes before RT
 * BCS followed by RT &plusmn; boost
 * Mastectomy
 * RT
 * pN2a RT (&ge;4 axillary LNs)
 * Consider RT
 * 1-3 LN+
 * T3
 * Margin <1mm consider RT
 * NAC if does not qualify for BCS

Clinically node positive
&ge;N2 | T4 (not inflammatory)

Options: For systemic adjuvant therapy see below, chemo comes before RT
 * NAC
 * Response: Mastectomy or BCS + RT
 * No Response: Individualize - more chemo, neoadj RT

Surgical LN Staging

 * If cN+ after biopsy, all patients get axillary dissection lvl 1-2
 * If gross lvl 2 or 3, dissect 3
 * SNLB
 * Negative - no further needed
 * Positive
 * If ALL are met, no further needed, otherwise ALND lvl 1+2
 * &le;T2
 * 1-2 +SLN
 * Patient getting BCS + WBRT without NAC
 * Not found: ALND lvl 1+2

Adjuvant systemic therapy
Mainstays of treatment:
 * Hormone Therapy (HT)
 * Chemotherapy (CT)
 * Trastuzumab (T)

Algorithm for treatment
 * 1) &le;5mm - Consider HT
 * 2) >5mm | N1mi - HT
 * 3) *Consider CT, Trastuzumab
 * 4) &ge;1cm | pN1 - All 3

Aberrations of above algorithm:
 * If group 2 and HR+, do 21 gene assessment, then group 1,2,3 as &le;18, &le;30, >30 respectively
 * If HR+, Mucinous or Tubular histology
 * &le;3cm Consider HT
 * &ge;pN1 HT consider chemotherapy

Also
 * If HR- no HT, if HER2- no T

Radiotherapy Methods (RT)

 * Whole Breast RT (WBRT) or Chest wall RT (including reconstruction)
 * Standard is 50Gy/25Fx [46-50Gy/23-25Fx]
 * &plusmn;boost to cavity 10Gy/5Fx [10-16Gy/4-8Fxs]
 * Hypofractionated
 * Consider for >50yo, &le;T2N0, no NAC
 * 40Gy/15Fxs [40-42.5Gy/15-16Fxs]

RNI
 * &ge;4 LN+: To all nodes (at risk axilla, IM, SCN)
 * 1-3 LN+ strongly consider to all nodes or at least LVL 1-2
 * T3 (>5cm) consider consider to all nodes or at least LVL 1-2

APBI

38.5Gy/10Fx BID or 34Gy/10Fx Brachy to tumor bed


 * Needs to meet all criteria
 * Suitable
 * &ge;50yo, -BRCA, &le;T2 (2cm), ER+, N0, no NAC, no EIC
 * DCIS allowed if screen-detected, low - int grade, <2.5cm, margins >3mm,
 * LCIS allowed
 * Cautionary 40-49 yo + all above, or &ge;50 with only 1 of below:
 * 2.1-3cm invasive focus, T2, margins <2mm, limited LVSI, ER-, pure DCIS &le;3cm, EIC &le;3cm

Breast Conserving Therapy (BCS)
aka lumpectomy

Contraindications (CI):
 * Can't get RT: i.e. prev RT, scleroderma, pregnant
 * Diffuse suspicious microcalcifications
 * R+ surgery predicted

Not CI (however considerations):
 * Young
 * Non-biopsied MRI findings
 * Systemic lupus
 * BRCA
 * High grade/Trip negative