Abstract #4210

Effects of Intensity Modulated Radiotherapy (IMRT) on Prostate Volume Comparison of 39 Patients Before and After Radiotherapy

Christian M. Zechmann¹, Khurram Aftab¹, Patrik Zamecnik¹, Frederik L. Giesel¹, Christian Thieke², Jurgen Ftterer³, Anette Kopp-Schneider⁴, Stefan Delorme⁵

¹Radiology, German Cancer Research Center (DKFZ), Heidelberg, Baden-Wuerttemberg, Germany; ²Radiotherapy, German Cancer Research Center (DKFZ), Heidelberg, Baden-Wuerttemberg, Germany; ³Radiology, University Medical Centre Nijmegen, Nijmegen, Netherlands; ⁴Biostatistics, German Cancer Research Center (DKFZ),, Heidelberg, Baden-Wuerttemberg, Germany; ⁵Radiology, German Cancer Research Center (DKFZ),, Heidelberg, Baden-Wuerttemberg, Germany

The shrinking effect of androgen deprivation therapy (ADT) on prostate volume is a known finding but data on volume changes during radiotherapy is inconsistent. We examined patients with and without ADT undergoing intensity modulated radiotherapy (IMRT). Patients undergoing IMRT show definite prostate shrinkage in T2w MRI. The rate is slowed down after 6 months in both groups, whereas the volume reduction is significantly larger in patients without ADT. Nevertheless there is no adding effect of ADT+IMRT vs. IMRT alone.