Vincent Vinh-Hung, Presenter: Nothing to Disclose

Hendrik Everaert MD, Abstract Co-Author: Nothing to Disclose

Samuel Bral, Abstract Co-Author: Nothing to Disclose

Frederik Vandenbroucke MD, Abstract Co-Author: Nothing to Disclose

Johan de Mey, Abstract Co-Author: Nothing to Disclose

Guy A. Storme MD, PhD, Abstract Co-Author: Nothing to Disclose

To assess the utility of pre-operative FDG-PET, acquired before surgery for breast cancer, when patients are referred later for post-operative radiation treatment.

In our center (AZ-VUB), patients with nodal involvement are treated to a dose of 50 Gy using in-house standard fields and conventional radiation treatment planning based on CT. Retrospectively in 2003-2004, 15 patients with a preoperative FDG-PET showing axillary lymph node involvement were identified. An updated treatment planning was performed in these patients using image fusion of CT with the preoperative FDG-PET. The location of involved lymph nodes identified by the FDG-PET was defined as target volume. Adequacy of dose delivery was assessed by comparing the dose volume histograms of the original conventional planning (performed ignoring FDG-PET information), and the updated planning (performed using FDG-PET information). Comparisons of mean values used the Student t-test.

In 13 patients an image fusion could be performed. Dose computation showed underdosage at the location of involved lymph nodes in 11 out of 13 patients, with half of the volumes of the lymph nodes receiving a dose of 20 Gy to 48 Gy instead of the prescribed 50 Gy. Delivery of the prescribed dose required planning adjustment, with a statistically significant improvement of the computed dose (p<0.01), without increasing the dose to the lungs.

Standard radiation portals in postoperative radiation therapy for breast cancer with lymph node involvement do not automatically result in an adequate dose delivery to the region of highest biological activity identified by preoperative FDG-PET. When preoperative FDG-PET is available, the image information should be integrated with the CT treatment planning.

Vinh-Hung, V, Everaert, H, Bral, S, Vandenbroucke, F, de Mey, J, Storme, G, Pre-operative FDG-PET and CT Image Fusion in the Post-operative Radiation Treatment of Breast Cancer.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4408338.html