Prospective assessment of deep inspiration breath-hold using 3-dimensional surface tracking for irradiation of left-sided XXXX .

@entity1161 @entity1 @entity0 @entity299
PURPOSE: Deep inspiration breath hold (DIBH) is used to decrease cardiac irradiation during @entity1161 ( @entity1161 ) for @entity0 . The @entity1 most likely to benefit and the impact on treatment time remain largely unknown. We sought to identify predictors for the use of DIBH and to quantify differences in dosimetry and treatment time using a prospective registry. METHODS AND MATERIALS: A total of 150 @entity1 with @entity0 were enrolled. All @entity1 were simulated with both free breathing (FB) and DIBH. @entity1161 was delivered by either modality. Alternate scans were planned with use of deformable registration to include identical @entity1161 volumes. DIBH @entity1 were monitored by a real-time surface tracking system, AlignRT (Vision @entity1161 , Ltd, London, United Kingdom). Baseline characteristics and treatment times were compared by Fisher exact test and Wilcoxon rank sum test. Dosimetric endpoints were analyzed by Wilcoxon signed rank test, and linear regression identified predictors for change in @entity299 (   @entity299 ). RESULTS: We treated 38 @entity1 with FB and 110 with DIBH. FB @entity1 were older, more likely to have @entity299 , and less likely to receive chemotherapy or immediate reconstruction (all P < .05). Treatment times were not significantly different, but DIBH @entity1 had greater variability in times (P = .0002). Of 146 evaluable @entity1 , DIBH resulted in >20 cGy improvement in @entity299 in 107 @entity1 but a >20 cGy increase in @entity299 in 14. Both @entity299 and lung V20 were significantly lower in DIBH than in paired FB plans. On multivariate analysis, younger age (4.18 cGy per year; P < .0001), higher body mass index (6.06 cGy/kg/m(2); P = .0018), and greater change in lung volumes (130 cGy/L; P = .003) were associated with greater    @entity299 . CONCLUSIONS: DIBH improves cardiac dosimetry without significantly impacting treatment time in most @entity1 . Greater inspiratory lung volumes augment this benefit. Because the improvement with DIBH was not uniform, @entity1 should be scanned with both FB and DIBH.
