RadOnc Resident Wiki/Breast/Breast overview

Clinically node negative Or T3N1, No T4 Options: BCS followed by RT ± boost Mastectomy RT pN2a RT (≥4 axillary LNs) Consider RT 1-3 LN+ T3 Margin <1mm consider RT NAC if does not qualify for BCS For systemic adjuvant therapy see below, chemo comes before RT Clinically node positive ≥N2 | T4 (not inflammatory) Options: NAC Response: Mastectomy or BCS + RT No Response: Individualize - more chemo, neoadj RT For systemic adjuvant therapy see below, chemo comes before 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 ≤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 ≤5mm - Consider HT >5mm | N1mi - HT Consider CT, Trastuzumab ≥1cm | pN1 - All 3 Aberrations of above algorithm: If group 2 and HR+, do 21 gene assessment, then group 1,2,3 as ≤18, ≤30, >30 respectively If HR+, Mucinous or Tubular histology ≤3cm Consider HT ≥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] ±boost to cavity 10Gy/5Fx [10-16Gy/4-8Fxs] Hypofractionated Consider for >50yo, ≤T2N0, no NAC 40Gy/15Fxs [40-42.5Gy/15-16Fxs] RNI ≥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 ≥50yo, -BRCA, ≤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 ≥50 with only 1 of below: 2.1-3cm invasive focus, T2, margins <2mm, limited LVSI, ER-, pure DCIS ≤3cm, EIC ≤3cm Neoadjuvant Chemotherapy (NAC) 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