Daisuke Kakihara, Presenter: Nothing to Disclose

Akihiro Nishie MD, Abstract Co-Author: Nothing to Disclose

Tsuyoshi Tajima MD, PhD, Abstract Co-Author: Nothing to Disclose

Yoshiki Asayama MD, Abstract Co-Author: Nothing to Disclose

Kousei Ishigami MD, Abstract Co-Author: Nothing to Disclose

Hiroshi Honda MD, Abstract Co-Author: Nothing to Disclose

Tomohiro Nakayama MD,PhD, Abstract Co-Author: Nothing to Disclose

Daisuke Okamoto MD, Abstract Co-Author: Nothing to Disclose

Nobuhiro Fujita MD, Abstract Co-Author: Nothing to Disclose

Seiji Naito, Abstract Co-Author: Nothing to Disclose

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

To evaluate efficacy of apparent diffusion coefficient (ADC) map in predicting the prognosis of patients with renal cell carcinoma (RCC).

A total of 52 renal cell carcinomas (38 males and 14 females, aged 37-83 years) were included in our study. All cases underwent MR imaging before surgical operation and were diagnosed malignant renal tumor by resection. They included the following histological variants of RCC: clear cell carcinomas, 43; papillary RCC, 6; and other types of RCC, 3. All MR examinations were performed with 1.5T superconducting MR unit. T1-weighted images before and after Gd administration, T2-weighted image, and diffusion weighted image (DWI) were obtained. DWI was performed using single shot spin echo-planar imaging (EPI) with three different b-values (0, 500, and 1000). An ADC map using software on the console unit was acquired. Solid component of the tumor was defined by two radiologists in a consensus fashion using Gd-enhanced T1-weighted image as reference, for which ADC value was measured on the ADC map.

Over a follow-up period of 3 years, sixteen patients (30.8%) developed a recurrence: lung metastases (n=12), liver metastasis (n=1), bone metastasis (n=1), lymph node metastasis (n=1), and left gluteal muscle metastasis (n=1). Mean ADC values of the primary tumors in the patients with recurrence and the disease-free survivors were 1.22×10-3 mm2/s and 1.55×10-3 mm2/s, respectively. The former was significantly lower value than the latter. Especially, in the patients with RCC with an ADC value higher than 1.75×10-3mm2/s, recurrence rate was only 8% (1/13). The Kaplan-Meier curve for disease-free survival showed significant difference between the patients with ADC value of over and under 1.75×10-3 mm2/s. However, multiple logistic regression analysis revealed that tumor size was the only independent prognostic factor: there was moderate correlation between ADC value and tumor size. These results might imply that ADC value of the RCC would be gradually decreasing with progression of the tumor grade and stage.

RCC with a higher ADC value showed a better prognosis compared with than that with a lower ADC value.

Especially, RCC with higher ADC value was expected to have a good prognosis, therefore ADC value would have a high degree of clinical usability.

Kakihara, D, Nishie, A, Tajima, T, Asayama, Y, Ishigami, K, Honda, H, Nakayama, T, Okamoto, D, Fujita, N, Naito, S, et al, 0, Prognostic Value of Apparent Diffusion Coefficient Map in Renal Cell Carcinoma.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8003878.html