Lixia Wang MD, Presenter: Nothing to Disclose

RenYou Zhai MD, Abstract Co-Author: Nothing to Disclose

To observe the occurrence time, morphologic characteristics and developing courses of late radiation brain injury (RBI) after radiotherapy in patients with nasopharyngeal carcinoma (NPC)

71 patients  with known RBI after radiation therapy for NPC were studied respectively. Consecutive follow-up MR imaging examination performed in patients after radiotherapy for NPC from 1.5-164 months interval were reviewed in detail. MR imaging was performed with  0.5 T MR unit.

The shortest time of occurring RBI was at 1.5 months after irradiation, and the longest time was at 164 months later. 9.9% patients were found RBI within 12 months after radiotherapy, and 40.8% patients were found RBI within 12 to 36 months,28.2% patients were found RBI within 3 to 5 years , 21.1%  patients found RBI were over 5 years. 92.2%lesions in brain lobes involved in the temporal lobes Based on the MR signal features, RBI was divided into three types: diffuse edema, local necrosis  and local cysts. Developing courses in the follow-up in 40 patients with RBI: lesions were found enlarged and the median time was 11 months(1-48 months) after RBI were diagnosed; lesion were found shrinked in the follow-up and the median time was 18.5 months(3-53 months), and statistically significant difference was found between two groups (P=.036). Cystic changes were found in 13 cases, the median time was 29 months (range 10-84 months) after RBI was diagnosed.

RBI in patients with NPC were mostly found within 5 years after radiotherapy. MRI could show the shapes, locations and intra-stuctures of RBI clearly. It also could be used to observe the developing courses of RBI in the follow-up.

It is important to know the occuring time and developing course of RBI.  This reasearch could provide helpful information to clinicians in therapy of RBI.

Wang, L, Zhai, R, Developing Courses of Late Radiation Brain Injury in Patients with Nasopharyngeal Carcinoma after Radiation Therapy: Morphologic Evaluation with MR Imaging.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12031535.html