الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Conclusion
High grade gliomas represents around 25% of all brain tumors in adults while the percentage is much lower in pediatric age group. 3D-CRT and IMRT are an effective treatment modality with less toxicity than conventional techniques. Most recurrence occurs within the treatment PTV suggesting a need for more directed therapy against the treatment PTV is needed.
According to cox regression model; histological grade 4, thalamic extension, PS ≥60 and MTD are the independent factor that affect OS with hazard ratio of 8.88, 7.55, 0.27 and 9.95 respectively, while for PFS the HR are: 7.33, 6.78, 0.28 and 8.39 respectively.
Moreover, HGG pediatric patients are somewhat different from that of the adults in frequency, location and factors affecting prognosis. Like adults; Pathological grade 4 remains one of the key prognostic factors that affect disease outcome. Performance status is still a factor; however contrary to the adults whom PS <90 below considered adverse factor, PS below 60 in pediatric group is considered an adverse event. Thalamic extension is a unique adverse factor for pediatric age group. Finally RT dose, resection vs. biopsy, concurrent chemotherapy and post-RT chemotherapy maintenance have not that obvious effect on prognosis of pediatric age group when compared to that in the adult age group.
The risk score of HGG based on the status of performance status, thalamic extensions, tumor grade and MTD is linked to both the OS and PFS; low risk (40 and 35 months, respectively), intermediate low (18.5 and 13.5 months ,respectively), intermediate high (9.5 and 6 months ,respectively) and high risk (2.5 and 0 months ,respectively) (P = 0.000). The low and intermediate low risk have better median OS than adults groups III and IV in to RTOG-RPA report (40 vs. 18 months) and (18.5 vs. 11) respectively. While intermediate high is quite similar in median OS (9.5 vs. 9 months) compared to adult group V. The high risk group is worse in median OS than adults group VI (2.5 vs. 5 months) respectively.
Recommendation
The risk score reached in this study needs validation in another independent study group of pediatric patients. Prospective randomized study may be needed to confirm the validity of this risk score together with tailoring treatment according to this score. This may change the adopted policy for treatment of pediatric HGG with trial at decreasing treatment burden in the low risk pediatric children and increasing treatment intensity in the high risk patients in order to reach optimum clinical end results.