TY  - JOUR
AB  - BACKGROUND: Sentinel lymph node biopsy (SLNB) can be safely omitted in selected early-stage, clinically node-negative breast cancer (BC) patients. While these patients are also candidates for partial breast irradiation (PBI), the dosimetric effects of PBI on the sentinel lymph node region (SLNs) and axillary levels remain unclear. METHODS: In this study, SLNs were identified and contoured in 100 BC patients using pre- and postoperative imaging. Axillary levels were contoured following ESTRO guidelines. Dose distribution to the SLN (n = 9000 data points) and axillary levels (n = 270 data points) were analyzed for whole breast irradiation (WBI) and PBI across different techniques (3D-conformal radiation therapy [3D-CRT] vs. volumetric modulated arc therapy [VMAT]), deep inspiration breath-hold [DIBH] vs. free breathing [FB]), and anatomical variations (breast size, tumor site, and upper breast border). RESULTS: WBI provided full therapeutic dose coverage (>95 % of the prescribed dose) to 65 % of SLNs, compared to only 10 % (3D-CRT) and 3 % (VMAT) with PBI. DIBH significantly reduced dose distribution to SLN and axillary levels compared to FB. Lower incidental dose coverage was also observed in patients with medial/central tumors, smaller breasts, and lower upper breast borders. CONCLUSION: These results demonstrate that PBI delivers substantially lower incidental dose to the SLN than WBI. Since patients in the INSEMA and SOUND trials were predominantly treated with WBI, combining SLNB omission with PBI should not be considered a standard approach and warrants further investigation.
AU  - Behzadi, S.T.*
AU  - Moser, R.*
AU  - Düsberg, M.*
AU  - Aigner, M.*
AU  - Nano, J.*
AU  - Kiesl, S.*
AU  - Lammert, J.*
AU  - Klein, E.*
AU  - Schmidt, G.P.*
AU  - Kiechle, M.*
AU  - Huber, T.*
AU  - Corradini, S.*
AU  - Combs, S.E.
AU  - Borm, K.J.*
C1  - 75072
C2  - 57790
TI  - Partial breast irradiation after sentinel lymph node biopsy omission: Is it a valid alternative to whole breast Irradiation? Analysis of the dose to the sentinel lymph node region during whole breast irradiation vs. partial breast irradiation.
JO  - Breast
VL  - 82
PY  - 2025
SN  - 0960-9776
ER  - 

TY  - JOUR
AB  - PURPOSE: Randomized studies demonstrated the oncological equivalence of (ultra-)hypofractionation compared to a 5-week schedule in postoperative radiotherapy of breast cancer. Due to the low incidence and long latency of secondary malignancies, there are currently no reliable clinical data regarding the influence of fractionation regimens on the development of secondary malignancies. MATERIAL AND METHODS: For 20 patients with right or left-sided breast cancer, postoperative treatment plans were created using 3D-CRT (n = 10) or VMAT (n = 10) for three different fractionation schedules: 5-week schedule with 50.4Gy in 1.8Gy (28fx), hypofractionation with 40.05Gy in 2.67Gy (15fx) and ultra-hypofractionation with 26Gy in 5.2Gy (5fx). The EARs (absolute additional cases of disease per 10,000 patient-years) for secondary malignancies in the lung, contralateral breast, esophagus, liver, thyroid, spinal cord, bones and soft tissue were calculated using a fraction-dependent dose-response model. RESULTS: Based on risk modulation, (ultra-)hypofractionation resulted in significantly lower EARs for lung cancer (LC), contralateral breast cancer (CBC) and soft tissue sarcoma (STS) (p < .001). For the ultra-hypofractionated dose concept the median EARs for LC, CBC and STS were 42.8 %, 39.4 % and 58.1 % lower compared to conventional fractionation and 31.2 %, 25.7 % and 20.3 % compared to hypofractionation. The influence of fractionation on the risk of secondary malignancies for LC and CBC was less pronounced with 3D-CRT than with VMAT. For STS, however, the influence of fractionation was greater with 3D-CRT than with VMAT. CONCLUSION: Based on this simulation study (ultra-)hypofractionated postoperative breast cancer irradiation may be associated with a lower risk of secondary malignancies compared to a 5-week schedule.
AU  - Kiesl, S.*
AU  - Düsberg, M.*
AU  - Behzadi, S.T.*
AU  - Moser, R.*
AU  - Nano, J.*
AU  - Huber, T.*
AU  - Klein, E.*
AU  - Kiechle, M.*
AU  - Bernhardt, D.*
AU  - Combs, S.E.
AU  - Borm, K.J.*
C1  - 71971
C2  - 56497
CY  - Journal Production Dept, Robert Stevenson House, 1-3 Baxters Place, Leith Walk, Edinburgh Eh1 3af, Midlothian, Scotland
TI  - The impact of fractionation on secondary malignancies in postoperative breast cancer irradiation.
JO  - Breast
VL  - 78
PB  - Churchill Livingstone
PY  - 2024
SN  - 0960-9776
ER  -