“… If the boost is necessary: - postponed up to 3 months for high-risk patients and up to 6 months for low-risk patients Delay of definitive radiotherapy for good-risk tumors | HR+, HER2- (Adjuvant setting): 42.6 Gy / 16 frs or 40 Gy / 15 frs (Hypo-F RT) ( Raghavan et al, 2020 ) | | Postop RT: for several weeks or even months | Adjuvant local RT in early-stage breast cancer: 26 Gy /5 frs over 1 week is non-inferior to 40 Gy / 15 frs over 3 weeks for (UK FAST-forward trial) ( Upadhyay and Shankar, 2020 ) |
boost RT in selected patients | adjuvant RT: up to 3 months after surgery | Hypo-F RT for adjuvant treatment ( Ng et al, 2020a ) |
Certain non-invasive carcinomas with good prognosis factors (Age > 40 yrs, tumors < 2.5 cm, low and intermediate grade, and sufficient surgical margins ≥ 2 mm) Age > 65 yrs (or with comorbidities) with invasive BC with good prognostic factors (grade 1-2, hormone-positive, tumors < 3 cm, Node-, HER2-) Boost for patients > 40 yrs without risk factors (LVI, high grade, hormone-negative, and positive surgical margins) | adjuvant RT: -low-risk disease -In-situ carcinoma (CIS) by 3-6 months For postmenopausal patients > 65 yrs with stage I or II and hormone-dependent disease, or patients with significant comorbidities: by 3 to 6 months | Adjuvant RT for high-risk BC: -Stages T3 or N-positive -Stages T1/T2N0 with risk factors (LVI, high grade, margins+, and HR-) Hypo-F RT: 42 Gy / 15 frs Ultra Hypo-F RT: 28/30-Gy in once weekly fractions over 5 weeks or 26-Gy in 5 daily fractions over 1 week as per the FAST and FAST Forward trials (N- tumors without boost). ( Ismaili and El Majjaoui, 2020 ) |
Boost: age > 50 yrs with ER+, HER-2- invasive type tumor without other adverse pathologic features Standard BCS RT: age > 70 yrs with small, grade I-II, and HR + tumor RT after excision for low-intermediate grade DCIS, particularly in women over 60 yrs | | Adjuvant RT: Hypo-F RT (42.4 Gy /16 frs or 40 Gy / 15 frs) and standard regimen (50 Gy / 25 frs) for regional lymph nodes involvement ( Mahmoodzadeh et al, 2020 ) |
After BCS: - Low-risk elderly (≥ 65 yrs): WBRT for stage I, ER+/HER2− receiving adjuvant endocrine therapy, without impacting survival - DCIS: WBRT, especially for ER + disease receiving adjuvant endocrine therapy, without affecting overall survival. - Invasive disease with low-risk genomic profile -Boost: in invasive disease (except for patient ≤40 yrs or with positive margin) and in situ (except for positive margin; no survival benefit except for high-risk disease After mastectomy: T1-2 N+ | Low-risk elderly (≥65 yrs): WBRT... |
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