Optimized Volumetric Modulated Arc Therapy Versus 3D-CRT for Early Stage Mediastinal @entity978 Without Axillary Involvement: A @entity5 and XXXX Risk.

@entity1 @entity340 @entity0 @entity5 @entity2 @entity299 @entity978 @entity259 @entity1370 @entity65
PURPOSE: The purpose of this study was to evaluate the risks of second @entity5 and @entity65 associated with an optimized volumetric modulated arc therapy (VMAT) planning solution in a selected cohort of stage I/II @entity978 ( @entity978 ) @entity1 treated with either involved-node or involved-site radiation therapy in comparison with 3-dimensional conformal radiation therapy (3D-CRT). METHODS AND MATERIALS: Thirty-eight @entity1 (13 males and 25 females) were included. Disease extent was mediastinum alone (n=8, 21.1%); mediastinum plus unilateral neck (n=19, 50%); mediastinum plus bilateral neck (n=11, 29.9%). Prescription dose was 30 Gy in 2-Gy fractions. Only 5 @entity1 had mediastinal bulky disease at diagnosis (13.1%). Anteroposterior 3D-CRT was compared with a multiarc optimized VMAT solution. Lung, breast, and @entity259 risks were estimated by calculating a lifetime attributable risk (LAR), with a LAR ratio (LARVMAT-to-LAR3D-CRT) as a comparative measure. @entity1370 risks were estimated by calculating absolute excess risk (AER). RESULTS: The LAR ratio favored 3D-CRT for @entity2 induction risk in mediastinal alone (P=.004) and mediastinal plus unilateral neck (P=.02) presentations. LAR ratio for @entity0 was lower for VMAT in mediastinal plus bilateral neck presentations (P=.02), without differences for other sites. For @entity259 , no significant differences were observed, regardless of anatomical presentation. A significantly lower AER of cardiac (P=.038) and @entity340 (P<.0001) was observed for VMAT regardless of disease extent. CONCLUSIONS: In a cohort of @entity1 with favorable characteristics in terms of disease extent at diagnosis (large prevalence of nonbulky presentations without axillary involvement), optimized VMAT reduced @entity299 risk with comparable risks of @entity0 , with an increase in @entity2 induction probability. The results are however strongly influenced by the different anatomical presentations, supporting an individualized approach.
