Craniopharyngiomas: Surgery and Radiotherapy.

Abstract

Taking into account the benign nature of craniopharyngiomas, the main method of treatment is the resection of the tumor. However, the tendency of these tumors to invade critical structures (such as optic pathways, the hypothalamic-pituitary system, the Willis circle vessels) often limits the possibility of a radical surgery.Craniopharyngiomas of the third ventricle represent the greatest challenge for surgery. After radical surgery, hypothalamic disorders often occur, including not only obesity but also cognitive, emotional, mental, and metabolic disturbances. Metabolic disorders associated with damage to the hypothalamus progress after surgery and lead to impaired functions of the internal organs. This process is irreversible and, in many cases, becomes the direct cause of mortality. The life expectancy of patients with the surgically affected hypothalamus is significantly shorter than in patients with preserved diencephalic function. The incidence of hypothalamic disorders after surgery can reach 40%.Even with macroscopically total resection, craniopharyngiomas can recur in 10-30% of cases, and in the presence of tumor remnants and with no further radiation treatment, the risk of recurrence significantly increases to up to 50-85% according to various studies. For this reason, the observation of patients with residual tumors after surgery is an incorrect strategy.Radiation therapy significantly improves progression-free survival (PFS), and the use of stereotactic irradiation techniques ensures conformity of irradiation of tumor remnants with a complicated shape and location (Iwata H et al., J Neurooncol 106(3):571-577, 2012; Aggarwal et al., Pituitary 16(1):26-33, 2013; Savateev et al., Zh Vopr Neirokhir Im N N Burdenko 81(3):94-106; 2017), which potentially reduces the risk of undesirable postradiation effects. Therefore, the quality of life in patients with craniopharyngiomas infiltrating the hypothalamus is significantly higher after non-radical operations with subsequent stereotactic radiation than after a total or subtotal removal.