Hypopituitarism following Radiotherapy Revisited

Area of Science:

• Endocrinology
• Radiation Oncology
• Neuroscience

Background:

• Radiation damage to the hypothalamic-pituitary (H-P) axis is a common cause of neuroendocrine disturbances.
• The severity of these disturbances correlates with radiation dose and follow-up duration.
• The somatotropic axis is most vulnerable, leading to frequent growth hormone (GH) deficiency.

Purpose of the Study:

• To analyze the incidence and patterns of anterior pituitary hormone secretion disturbances after H-P axis radiation.
• To highlight the vulnerability of the somatotropic axis and the diagnostic challenges in assessing GH secretion.
• To emphasize the progressive and irreversible nature of H-P dysfunction and its impact on quality of life.

Main Methods:

• Review of existing literature and clinical data on patients with H-P axis radiation.
• Correlation analysis of radiation dose, follow-up time, and endocrine deficiencies.
• Discussion of diagnostic methods, including insulin tolerance testing, particularly in pediatric populations.

Main Results:

• GH deficiency is the most common endocrinopathy, occurring in up to 100% of patients with doses of 30-50 Gy.
• Long-term deficiencies in gonadotropins, TSH, and ACTH occur in 20-30%, 3-9%, and 3-6% of patients, respectively.
• Multiple hormonal deficiencies affect 30-60% of patients after high-dose cranial irradiation or conventional therapy for pituitary tumors.

Conclusions:

• H-P axis dysfunction following radiation is progressive and irreversible, impacting growth, body image, and quality of life.
• Precocious puberty and hyperprolactinemia are potential sequelae, particularly with higher radiation doses.
• Regular endocrine assessment and timely hormone replacement therapy are essential for managing patients.