Abstract #0156

Dynamic Contrast-Enhanced Magnetic Resonance for the Monitoring of Neoadjuvant Chemoradiation Therapy in Rectal Adenocarcinoma: Initial Experience with 20 Patients

Giuseppe Petralia¹, Gloria Castellazzi², Paul Summers¹, Roberto Di Filippi¹, Moreno Pasin², Maria Giulia Zampino³, Maria Cristina Leonardi⁴, Antonio Chiappa⁵, Stefano Viotti¹, Luke Bonello¹, Massimo Bellomi¹

¹Radiology, Istituto Europeo di Oncologia, Milan, Lombardia, Italy; ²Struttura Complessa di Radiologia/Diagnostica per immagini, Istituto Neurologico IRCCS- Fondazione Casimiro Mondino, Pavia, Lombardia, Italy; ³Medical Care Unit, Department of Medicine, Istituto Europeo di Oncologia, Milan, Lombardia, Italy; ⁴Radiotherapy, Istituto Europeo di Oncologia, Milan, Lombardia, Italy; ⁵General and Laparoscopic Surgery, Istituto Europeo di Oncologia, Milan, Lombardia, Italy

We prospectively monitored changes in contrast agent pharmacokinetics values in advanced rectal adenocarcinoma over the course of neoadjuvant chemoradiation (NACR) therapy using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and evaluated whether DCE-MRI findings correlated with response to NACR in 20 patients. ANOVA revealed no inter-group differences (complete responders, non responders, local downstaging) for mean pre- and post-therapy values, and no changes in values during therapy. T-tests showed significant differences in post-therapy median Ktrans and IAUC60 and in fractional change of Kep between complete and non-responsive groups. Median values of Ktrans and Kep significantly decreased, whilst Ve significantly increased post-therapy.