TY - JOUR
T1 - Hypofractionated whole-breast radiation therapy
T2 - Does breast size matter?
AU - Hannan, Raquibul
AU - Thompson, Reid F.
AU - Chen, Yu
AU - Bernstein, Karen
AU - Kabarriti, Rafi
AU - Skinner, William
AU - Chen, Chin C.
AU - Landau, Evan
AU - Miller, Ekeni
AU - Spierer, Marnee
AU - Hong, Linda
AU - Kalnicki, Shalom
PY - 2012/11/15
Y1 - 2012/11/15
N2 - Purpose: To evaluate the effects of breast size on dose-volume histogram parameters and clinical toxicity in whole-breast hypofractionated radiation therapy using intensity modulated radiation therapy (IMRT). Materials and Methods: In this retrospective study, all patients undergoing breast-conserving therapy between 2005 and 2009 were screened, and qualifying consecutive patients were included in 1 of 2 cohorts: Large-breasted patients (chest wall separation >25 cm or planning target volume [PTV] >1500 cm3) (nZ97) and small-breasted patients (chest wall separation <25 cm and PTV <1500 cm3) (nZ32). All patients were treated prone or supine with hypofractionated IMRT to the whole breast (42.4 Gy in 16 fractions) followed by a boost dose (9.6 Gy in 4 fractions). Dosimetric and clinical toxicity data were collected and analyzed using the R statistical package (version 2.12). Results: The mean PTV V95 (percentage of volume receiving >Z 95% of prescribed dose) was 90.18% and the mean V105 percentage of volume receiving >Z 105% of prescribed dose was 3.55% with no dose greater than 107%. PTV dose was independent of breast size, whereas heart dose and maximum point dose to skin correlated with increasing breast size. Lung dose was markedly decreased in prone compared with supine treatments. Radiation Therapy Oncology Group grade 0, 1, and 2 skin toxicities were noted acutely in 6%, 69%, and 25% of patients, respectively, and at later follow-up (>3 months) in 43%, 57%, and 0% of patients, respectively. Large breast size contributed to increased acute grade 2 toxicity (28% vs 12%, PZ.008). Conclusions: Adequate PTV coverage with acceptable hot spots and excellent sparing of organs at risk was achieved by use of IMRT regardless of treatment position and breast size. Although increasing breast size leads to increased heart dose and maximum skin dose, heart dose remained within our institutional constraints and the incidence of overall skin toxicity was comparable to that reported in the literature. Taken together, these data suggest that hypofractionated radiation therapy using IMRT is a viable and appropriate therapeutic modality in large-breasted patients.
AB - Purpose: To evaluate the effects of breast size on dose-volume histogram parameters and clinical toxicity in whole-breast hypofractionated radiation therapy using intensity modulated radiation therapy (IMRT). Materials and Methods: In this retrospective study, all patients undergoing breast-conserving therapy between 2005 and 2009 were screened, and qualifying consecutive patients were included in 1 of 2 cohorts: Large-breasted patients (chest wall separation >25 cm or planning target volume [PTV] >1500 cm3) (nZ97) and small-breasted patients (chest wall separation <25 cm and PTV <1500 cm3) (nZ32). All patients were treated prone or supine with hypofractionated IMRT to the whole breast (42.4 Gy in 16 fractions) followed by a boost dose (9.6 Gy in 4 fractions). Dosimetric and clinical toxicity data were collected and analyzed using the R statistical package (version 2.12). Results: The mean PTV V95 (percentage of volume receiving >Z 95% of prescribed dose) was 90.18% and the mean V105 percentage of volume receiving >Z 105% of prescribed dose was 3.55% with no dose greater than 107%. PTV dose was independent of breast size, whereas heart dose and maximum point dose to skin correlated with increasing breast size. Lung dose was markedly decreased in prone compared with supine treatments. Radiation Therapy Oncology Group grade 0, 1, and 2 skin toxicities were noted acutely in 6%, 69%, and 25% of patients, respectively, and at later follow-up (>3 months) in 43%, 57%, and 0% of patients, respectively. Large breast size contributed to increased acute grade 2 toxicity (28% vs 12%, PZ.008). Conclusions: Adequate PTV coverage with acceptable hot spots and excellent sparing of organs at risk was achieved by use of IMRT regardless of treatment position and breast size. Although increasing breast size leads to increased heart dose and maximum skin dose, heart dose remained within our institutional constraints and the incidence of overall skin toxicity was comparable to that reported in the literature. Taken together, these data suggest that hypofractionated radiation therapy using IMRT is a viable and appropriate therapeutic modality in large-breasted patients.
KW - Breast-conserving therapy
KW - Hypofractionated radiation therapy
KW - IMRT inverse planning
KW - Large breast size
KW - Prone treatment position
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U2 - 10.1016/j.ijrobp.2012.01.093
DO - 10.1016/j.ijrobp.2012.01.093
M3 - Article
C2 - 22543209
AN - SCOPUS:84872045019
SN - 0360-3016
VL - 84
SP - 894
EP - 901
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 4
ER -
