EP-1469 Radiation dose to pelvic floor muscles and functional outcome after treatment for anal cancer

S797 ESTRO 38Results 16 pts (13 male and 3 female) were enrolled, out of which 5 pts (31%) showed cCR.The most predictive radiomics feature was the "grey level non-uniformity" (glnu), whose variation resulted to be always significant in discriminating cCR pts from not responding ones (p= 0,0375 at t5; 0,0005 at t10; 0,0133 at t15; 0,0032 at t20; 0,0380 at t25).Volume variation resulted to be significant in 4 of the considered time fractions (p= 0,0490 at t5; 0,0032 at t10; 0,0636 at t15; 0,0055 at t20; 0,0275 at t25).The trends of glnu and volume are reported in figure 1 and 2 respectively for all the pts. ConclusionThis hypothesis generating study suggests that hybrid 0.35 T MRgRT images could be suitable for radiomics analyses despite the low spatial resolution and that radiomics parameters may perform better than standard tumor shrinkage measurements in the prediction of cCR.