Tumor volume and growth kinetics in hypothalamic-chiasmatic pediatric low grade gliomas

Pediatric low grade gliomas evidence a tendency towards quiescent growth, thus complicating the clinical management of nonresected tumors whose clinical behavior may be difficult to predict. We decided to explore the hypothesis of possible correlation in pediatric low grade glioma between tumor volume and growth rate. We identified 6 children with hypothalamic chiasmatic lesions. Five of these patients were treated only with biopsy and 1 with repeated partial tumor resection. All of 6 patients had 10-15 sequential brain MRI over a time span of 3-8 years. Tumor volume was determined using Sigma Scan Image software. The results were analyzed utilizing two equations for modeling tumor growth: exponential and Gompertz. In 4 patients whose tumor volume was approximately 80-100 cm(3) at the time of diagnosis, slow spontaneous partial regression was observed. In the other patients deceleratory or exponential tumor growth was volume-dependent. Our results suggest that growth of pediatric low grade glioma decelerates as tumor becomes large and that the Gompertz model for tumor growth is useful for understanding the growth kinetics of pediatric low grade glioma.