[The role of human chorionic gonadotropin in cerebrospinal fluid in the diagnosis and treatment of intracranial germinoma].

Objective: To study the cerebrospinal fluid (CSF) and serum level of human chorionic gonadotropin (HCG) in patients with intracranial germinoma and to evaluate its diagnostic and therapeutic value.
Methods: Thirty-one patients with intracranial germinoma receiving estimation of HCG in CSF and serum in our hospital were retrospectively analyzed in terms of HCG level, its influencing factors and the relationship of HCG with clinical features.
Results: HCG levels in CSF of the 31 cases ranged from 0.17 IU/L to 5316.98 IU/L with a median value of 3.44 IU/L. The sensitivity of diagnosis increased from 80.6% to 90.3%, when the cut point of HCG in CSF changed from 0.60 IU/L to 0.50 IU/L. The sensitivity increased from 83.9% to 93.5% when the cut point of the ratio of CSF/serum HCG decreased from 1.8 to 1.7. HCG level of germinoma located in pineal region was higher than that in basal ganglia region, while it is lowest in sellar region. The ratio of CSF/serum HCG in different parts showed no difference. Multiple risk factors analysis revealed that serum HCG (r = 0.886, P = 0.0001) and tumor size (r = 0.748, P = 0.0211) were positively correlated with the HCG level in CSF, while course of the disease, age and gender were not correlated. After radiation therapy, HCG in CSF and serum decreased dramatically as compared with those before radiation.
Conclusions: The HCG level and its dynamic change were sensitive marker of intracranial germinomas. Based on our analysis, HCG in CSF over 0.50 IU/L and the its ratio in CSF/serum over 1.7 were highly indicative of the possibility of intracranial germinomas.