Somatotroph pituitary neuroendocrine tumor treatment
Transsphenoidal adenomectomy (TSS) of somatotroph pituitary neuroendocrine tumor (PitNET) is the first-line treatment of acromegaly. Pharmacological treatment is recommended if surgery is contraindicated or did not lead to disease remission. The choice of treatment best fitting each patient should be based on thorough investigation of patients' characteristics 1)
Aggressive GH-secreting pituitary neuroendocrine tumors (GHPAs) represent an important clinical problem in patients with acromegaly. Surgical therapy, although often the mainstay of treatment for GHPAs, is less effective in aggressive GHPAs due to their invasive and destructive growth patterns, and their proclivity for infrasellar invasion.
Growth hormone-secreting pituitary neuroendocrine tumor should be treated surgically, often followed by radiation therapy. That acromegaly can be treated with surgery alone is very unlikely. However, debulking the tumor is very important. Radiation therapy results in 50% reduction in growth hormone levels within 2 years, followed by an additional 25% in the following 2 years. Thereafter, the growth hormone levels decline more slowly. Therefore, the lower the postoperative growth hormone level, the higher the chance of remission after radiation therapy. Medical treatment is used after surgery to suppress growth hormone secretion, awaiting the occurrence of the effects of radiotherapy. Octreotide is the treatment of choice. A long-acting formulation administered monthly is now available.
Somatostatin must be administered as a continuous infusion, while shorter-acting octreotide is administered tid-qid. Growth hormone receptor antagonists have been another addition to the treatment of acromegaly. Dopamine agonists also may be used but are not as effective as octreotide (approximately 30% of somatotropinomas respond).