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

Pediatric low grade gliomas evidence a tendency towards quiescent growth, t hus complicating the clinical management of nonresected tumors whose clinic al behavior may be difficult to predict. We decided to explore the hypothes is of possible correlation in pediatric low grade glioma between tumor volu me and growth rate. We identified 6 children with hypothalamic chiasmatic l esions. Five of these patients were treated only with biopsy and 1 with rep eated 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(R) software. The results were analyzed utilizing two equations for modeling tumor growth: exponential and Gompertz. In 4 patients whose tu mor volume was approximately 80-100 cm(3) at the time of diagnosis, slow sp ontaneous partial regression was observed. In the other patients decelerato ry or exponential tumor growth was volume-dependent. Our results suggest th at growth of pediatric low grade glioma decelerates as tumor becomes large and that the Gompertz model for tumor growth is useful for understanding th e growth kinetics of pediatric low grade glioma.