AIMS: To evaluate the incidental dose to the internal mammary chain (IMC) in @entity1 treated with three-dimensional conformal radiotherapy, to estimate the predictors affecting the magnitude of IMC receiving dose and to determine the predictive role of clinical parameters on survival. MATERIALS AND METHODS: Between 2009 and 2015, 348 @entity1 undergoing @entity138 for @entity0 were retrospectively analyzed. All @entity1 underwent our department's routine procedure for @entity0 . The internal mammary lymph nodes were contoured according to Radiation Therapy Oncology Group (RTOG) concensus. Based on each @entity1 's dose-volume histograms, the mean doses (D mean) to internal mammary gland were analyzed. Overall survival and disease-free survival were also evaluated. RESULTS: The median follow-up time was 38 (range 3-80) months. The D mean to IMC was 32.8  Gy and the dose delivered to IMC showed a greater coverage in modified radical mastectomy (MRM) group compared with breast conserving surgery (34.6 vs 26.7  Gy). The @entity5 and the N-stage of @entity5 affected the incidental dose to IMC. The @entity5 size, the number of involved lymph nodes, the percentage of involved lymph nodes, hormonal status, advanced @entity5 and advanced N-stage were the prognostic factors that affect survival. CONCLUSION: The IMC received meaningful incidental irradiation dose when treated with two opposite tangential fields and ipsilateral supraclavicular fossa with a single anterior field. The real effect of incidental dose on survival and the hypothesis about the benefit of incidental irradiation of IMC should be examined in clinical studies.

Unplanned irradiation of internal mammary lymph nodes in XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'T-stage', 'T-stage of tumor'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast cancer'] @entity138 :: ('MESH:C563738', 'Disease') :: ['RT']
@entity0 :: (MESH:D001943,Disease) :: ['breast cancer']
