Hidetoshi Ikeda, Shunsuke Sato, Toshiyuki Saginoya, Takamasa Kudo and Kazuo Watanabe
Object: During the last 10 years, 129 consecutive transsphenoidal operations for growth hormone (GH) secreting pituitary adenomas have been carried out. In the present study, 120 of the patients involved in these operations have been reviewed to evaluate the accuracy of diagnosis of adenoma, the cure rate, and to ascertain the favorable surgical effects of early surgical intervention.
Methods: A total of 120 GH secreting adenomas, including 95 patients with typical acromegaly and 25 patients with no apparent clinical features of acromegaly, were evaluated. The pituitary tumors were investigated by means of Magnetic Resonance (MR) imaging at 1.5T and 3T, composite 3T-MRI and [11C] Methionine-positron Emission Tomography (MET-PET) imaging and histological and immunohistochemical staining. The modern remission criteria (a glucose suppressed [nadir] GH level of less than 1.0 ng/ml, a random GH level of 2.5 ng/ml or less, and a normal sex and age adjusted insulin-like growth factor-1 [IGF-1] level) were used. To assess remission we examined these criteria at 1, 6 and 12 months after surgery.
Results: The diagnostic accuracy of 3T-MRI and composite MET-PET fusion 3T- MRI in localizing adenoma was 87 and 100%, respectively. The mean age of patients with pre-clinical acromegaly and acromegaly was 37.3 and 51.1 years, respectively. The mean preoperative GH levels in these patients were 4.85 and 34.7 ng/ml for preclinical acromegaly and acromegaly, respectively. The mean preoperative IGF-1 levels for pre-clinical acromegaly and acromegaly were 323 and 822 ng/ml, respectively. The mean volume of the adenoma in patients with pre-clinical acromegaly and acromegaly were 1.26 and 3.84 cm3, respectively. There was a significant difference (P <0.0001) between the pre-clinical acromegaly and acromegaly groups in terms of age, GH and IGF-1 levels, and tumor volume. The overall cure rate for growth hormone-secreting adenoma was 73% using modern criteria; the surgical cure rate for acromegaly patients was 65%, while the surgical cure rate for patients without obvious clinical features of acromegaly was 100%. Patients with pre-clinical acromegaly had a tendency to have smaller sized adenomas, a younger age, lower GH and IGF-1 levels, and a better surgical cure rate relative to patients with typical acromegaly. No complications such as carotid artery injury, hypothalamic injury, cerebrospinal fluid fistula or permanent diabetes insipidus occurred. Only one acromegaly patient had hypopituitarism after surgery.
Conclusions: Early detection of GH secreting adenoma is important since early surgical intervention can achieve a 100% cure rate without serious complications.PDF
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