Kyeong Hwa Ryu MD, Presenter: Nothing to Disclose

Seung Ho Kim MD, Abstract Co-Author: Nothing to Disclose

Jung Hee Yoon MD, Abstract Co-Author: Nothing to Disclose

Yedaun Lee MD, Abstract Co-Author: Nothing to Disclose

Yun-Jung Lim, Abstract Co-Author: Nothing to Disclose

Choong Ki Eun MD, Abstract Co-Author: Nothing to Disclose

To evaluate the added value of the diffusion-weighted imaging (DWI) for evaluating lymph node (LN) eradication after neoadjuvant chemoradiation therapy (CRT) in patients with locally advanced rectal cancer (LARC).

Institutional review board approved this retrospective study and waived informed consent. Ninety-five consecutive patients (64 men, 31 women; mean age: 59 years, range: 32-82 years) with LARC (≥T3 or LN metastasis) who underwent CRT and subsequent surgery, were enrolled in this study. All patients underwent pre-and post-CRT 1.5-T rectal MRI with DWI (b=0, 1000). To evaluate the added value of the DWI for evaluating LN eradication after CRT, two blinded radiologists independently read the pre-and post-CRT T2-weighted images (T2WI) first and then the combined image set of the T2WIs and pre-and post-CRT DWI with a four-week interval and recorded their confidence score for LN eradication with a 5-point scale on a per-patient basis. The diagnostic performances were compared between the two reading sessions for each reader by using pair-wise comparison of receiver operating characteristic curves. Histopathology reports served as the reference standard for LN eradication.

Study population consisted of LN-eradicated group (n=65) and non-eradicated group (n=30). The diagnostic performances did not significantly differ between the two reading sessions for both readers (AUC, for reader 1, 0.770, 0.774, p=0.8155; for reader 2, 0.794, 0.798, p=0.8588). The sensitivity, specificity and accuracy for LN eradication were stationary after adding DWI for both readers (for reader 1, from 88%, 63% and 80% to 88%, 73% and 83%, respectively; for reader 2, from 77%, 77% and 77% to 77%, 80% and 78%, respectively).

Adding DWI to T2WI provides no additional diagnostic benefit for evaluating LN eradication after CRT in patients with LARC.

Adding DWI to T2WI provides no additional diagnostic benefit for evaluating LN eradication after CRT in patients with LARC.

Ryu, K, Kim, S, Yoon, J, Lee, Y, Lim, Y, Eun, C, Diffusion Weighted Imaging for Evaluating Lymph Node Eradication after Neoadjuvant Chemoradiation Therapy in Locally Advanced Rectal Cancer.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13015488.html