Emily Wai Yee Tam MBBS, Presenter: Nothing to Disclose

Vicky Joo-Lin Goh MBBCh, Abstract Co-Author: Nothing to Disclose

Ian Simcock, Abstract Co-Author: Nothing to Disclose

James Stirling, Abstract Co-Author: Nothing to Disclose

Jane Taylor, Abstract Co-Author: Nothing to Disclose

Anwar Roshanali Padhani MD, Abstract Co-Author: Consultant, F. Hoffmann-La Roche Ltd (Roche Pharmeuticals) Consultant, IXICO Limited Consultant, Guerbet SA Advisory Board, Biotronics3D Ltd Advisory Board, OsteoTronics Limited Advisory Board, Bayer AG

Suzannah Mawdsley, Abstract Co-Author: Nothing to Disclose

Rob Glynne-Jones, Abstract Co-Author: Research support, Merck & Co, Inc Research support, F. Hoffmann-La Roche Ltd Research support, sanofi-aventis Group Speaker, sanofi-aventis Group Speaker, Pfizer Inc Speaker, F. Hoffmann-La Roche Ltd

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

Diffusion weighted MRI (DW-MRI) may potentially provide additional information in anal cancer. The aim was to assess the morphological and DW-MRI characteristics of anal cancer before and after definitive chemoradiation.

12 patients (5 male, 7 female; mean 64y) with proven squamous cell anal cancer and 6 controls with normal anal canal underwent 1.5T MRI: T1W, T2W & STIR sequences in axial, coronal & sagittal planes were supplemented by DW-MRI sequences at b values of 0, 150, 500, 800 s/mm2. Tumor size, signal intensity, anatomical extent, TNM stage and apparent diffusion coefficient (ADC) before and after chemoradiation were recorded and compared using Mann-Whitney with statistical significance at 5%.

All 18 patients (cancers & controls) had baseline imaging. 6/12 cancers were imaged in addition after completion of chemoradiation. Before treatment all tumors were visible and hyperintense on DW-MRI sequences. Mean tumor size was 6.7 cm. There were T1 (1), T2 (4), T3 (4), T4 (3) cancers; 10/12 had nodal involvement: N1 (3), N2 (1), N3 (6); 0/12 had metastases. Baseline mean tumor ADC was lower than normal controls (0.97 X 10-3 versus 1.13 X 10-3 mm2/s; p = 0.15). Following chemoradiation, reduction in tumor size (mean reduction = 69.3%; p = 0.002), signal intensity (iso or hypointense) and increase in ADC (mean increase = 56.9%; p = 0.004) occurred. There was no clinical evidence of residual disease 6 months following treatment.

DW-MRI increases anal cancer conspicuity. ADC is lower in untreated anal cancer than controls. Increases in ADC following completion of chemoradiation suggest a good response.

DW-MRI increases tumor conspicuity; increases in ADC indicate good treatment response.

Tam, E, Goh, V, Simcock, I, Stirling, J, Taylor, J, Padhani, A, Mawdsley, S, Glynne-Jones, R, et al, 0, Does Diffusion-weighted MRI Provide Additional Information in Anal Canal Carcinoma before and after Definitive Chemoradiation?.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8011881.html