Reduction of radiation XXXX by V20-constraints in @entity0 .

@entity1 @entity34176 @entity0 @entity55
INTRODUCTION: Adjuvant local-regional radiotherapy (LRRT) is routinely recommended for @entity0 @entity1 . It is well known being related to pulmonary side-effects. We studied post-RT radiological changes on X-ray and CT, and correlated the findings with Quality of Life (QoL), common dosimetric factors and co-variates. The results were compared with a previously reported cohort of 137 irradiated @entity1 . METHODS: 88 @entity1 underwent chest X-ray and CT pre-and 4-5 months after 3-D planned LRRT, minimizing the dose to the ipsilateral lung to V       < 30%. The lung field was divided into 3 regions and the development of post-RT density changes were graded (0-3). @entity1 with radiological changes were compared with non-responders. Clinical symptoms were registered and data on @entity1 and treatment related co-variates were gathered prospectively. The ipsilateral lung dosimetric factors V      , V      , V       and mean dose were calculated and QoL was assessed before and 4 months after RT. RESULTS: The use of dose-volume constraints significally reduced moderate-severe radiological changes on chest X-ray compared with our earlier study (Chi square trend test: p < 0.001). Symptomatic @entity55 was also rare in the present study. No agreement was found between CT and chest X-ray as diagnostic tools for post-RT @entity55 . @entity34176 correlated independently with radiological changes on CT (logistic regression: p = 0.04; ROC area: 0.7). The Co-variates smoking habits, age, chemotherapy, endocrine or trastuzumab therapy did not influence the outcome on multivariate analysis. QoL changes in physical function, i.e. fatigue, dyspnoea were not detected but there was a trend for a worse recovery after chemotherapy in @entity1 with high @entity34176 (Spearman Rank Correlation: p < 0.05). CONCLUSIONS: The use of dose-volume constraints significantly reduced post-RT radiological changes on chest X-ray in LRRT for BC. The lung changes on CT were also generally limited when we used this strategy and was not always picked up on chest X-ray. Variation in V       alone was correlated with occurrence of lung changes on CT.
