1. Department of Radiation Oncology, Tohoku University School of Medicine
#2067
Assessment of Myocardial Metabolic Disorder Associated with Mediastinal Radiotherapy for Esophageal Cancer -a pilot study-
Rei Umezawa
Department of Radiation Oncology, Tohoku University School of Medicine
We evaluated the dose-effect relations for myocardial metabolic disorders by performing I-123 BMIPP scintigraphy after mediastinal RT.
Between 2011 and 2012, we performed I-123 BMIPP scintigraphy for 5 patients with esophageal cancer before and six months after curative mediastinal RT

2. Evaluation of the relations between RT dose and myocardial metabolic disorder
Normalization was applied on the mean of SPECT counts in the regions of the myocardium receiving less than 5 Gy, assuming that such a low RT dose has no significant influence. The mean of SPECT counts in each dose region (interval of 5 Gy) was determined, and relative values in each dose region were calculated on the basis of this normalization for each patient. The reduction in the percent of relative values at pre- and post-RT SPECT was calculated in each dose region.

3. Dose-effect relations for reduced uptake tended to be observed at 6 months after RT on average of 8.96% decrease in regions at Gy, 12.6% decrease in regions at Gy, 15.6% decrease in regions at Gy, 19.0% decrease in regions at Gy and 16.0% decrease in regions at Gy.

4. A remarkable case (Case 5)
Pre-RT
Post-RT
Reduced uptake corresponding to anterior-posterior fields was observed (40 Gy line).
We may need to make an effort to reduce high-dose mediastinal RT to myocardium in RT planning.