Pietro Andrea Bonaffini MD, Presenter: Nothing to Disclose

Davide Ippolito MD, Abstract Co-Author: Nothing to Disclose

Isabella Macchi MD, Abstract Co-Author: Nothing to Disclose

Fausto Rossini MD, Abstract Co-Author: Nothing to Disclose

Alessandro Maria Di Lelio MD, Abstract Co-Author: Nothing to Disclose

Sandro Sironi MD, Abstract Co-Author: Nothing to Disclose

To assess the added value of apparent diffusion coefficient (ADC) in the evaluation of response to chemotherapy (CT) in patients with Multiple Myeloma (MM).

A total of 18 patients with histologically proven MM underwent WB-MRI examination (1.5 T scanner, Achieva, Philips) from the skull vertex to the feet, before and after treatment, with the following protocol: coronal and sagittal short tau inversion recovery (STIR) T2, T1 TSE and axial DWIBS sequences (b factor: 0, 500 and 1000 mm2/sec). DWIBS images were compared with standard T1 and STIR images in five districts (skull; spine; sternum and ribs; pelvis; upper and lower limbs) to evaluate response to treatment. .The mean ADC values of the tumour bone regions were calculated, with the determination of percentage variation of ADC (ΔADC), before (MR1) and after (MR2) CT treatment and compared between responders and non-responders patients. ROI were manually drawn along contours of the tumours on each slice of ADC maps covering the entire tumours.

The primary bone tumor was correctly detected in all the patients at both MR imaging and the response to CT treatment was established with imaging follow-up (intensity signal decrease of over a period of time). On sense DWI the tumor appeared as high signal intensity as compared with normal bone marrow, and the mean ADC values was on MR1: 0.54 ± 0.22 x10-3 mm²/sec and on MR2: 0.99 ± 0.25 x10-3 mm²/sec. The mean percentage of tumour ADC change in the responders (Δ=66%) group was significantly different (p<0,05) than that in the non-responders group (Δ=15%), in relation to the higher cellularity that characterized the neoplastic bone marrow involvement than normal bone.

MR DWI is a non invasive imaging approach able to predict and monitor early therapeutic response in patients with MM, by determining individual changes of tumor ADC values corresponding to biological changes within the tumor tissue.

This preliminary findings shows that quantitative DWI evaluation by ADC maps offers a further non invasive tool in terms of monitoring the therapeutic response in MM patients.

Bonaffini, P, Ippolito, D, Macchi, I, Rossini, F, Di Lelio, A, Sironi, S, MRI with Diffusion-weighted Imaging and Apparent Diffusion Coefficient (ADC) in the Assessment of Response to Treatment in Patients with Multiple Myeloma: Preliminary Results.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11007117.html