Growth hormone rebound after cessation of sms 201-995 treatment in acromegaly

Long-term effects of octreotide on pituitary gigantism: its analgesic action on cluster headache

We report the case of 19-year-old man with pituitary gigantism due to growth hormone-producing pituitary macroadenoma. The patient complained of recurrent headache and excessive growth spurt since age 15. Octreotide administration was initiated following transsphenoidal pituitary adenomectomy. Octreotide injection for 4 years efficaciously reduced the size of remnant adenoma as well as serum growth hormone levels. Notably, octreotide exhibited a potent analgesic effect on his intractable cluster headache that has continued even after reduction of the adenoma volume. The analgesic effect lasted 2 to 6 hours after each injection and no tachyphylaxis to octreotide appeared during 4-year treatment. To characterize the headache and the pain intensity, analgesic drugs including octreotide, lidocaine, morphine and thiopental were tested using a visual analogue scale (VAS) evaluation, with the result that octreotide exhibited a prompt and complete disappearance of the headache. Headache relief was in part reproduced by morphine injection (56% reduction) but not by lidocaine or thiopental. The present case suggests that the intractable headache associated with pituitary gigantism is possibly related to the endogenous opioid system. Thus, the headache control by octreotide is clinically helpful for continuation of the self-injection regimen.

Role of radiation therapy in clinical hormonally-active pituitary adenomas

BACKGROUND AND PURPOSE

The outcome following radiation therapy (RT) of hormonally-active pituitary adenomas was assessed. The purpose of this analysis was to determine the control rate after radiation, identify any prognostic factors and evaluate the late toxicity.

MATERIALS AND METHODS

From 1972 to 1986, 145 patients received RT for hormonally-active pituitary adenomas. The median age was 39 years (range 15-76), with 81 males and 64 females. There were 52 patients with acromegaly, 64 with prolactinoma, and 29 with Cushing's disease. The median follow-up was 7.3 years. RT was given as primary treatment in 17 patients, after initial surgery in 65 patients, and as part of salvage therapy in 63 patients. The median total dose was 50 Gy (daily fraction: 2 Gy). Tumor control was defined as normalization of basal hormonal level and lack of progression of adenoma assessed by imaging studies. The following factors were analyzed for prognostic significance in tumor control: age, sex, tumor type, direction of tumor extension, radiation dose, and radiation field size.

RESULTS

The 10-year actuarial proportion of patients with persistent elevated hormone level were 61% following RT alone, and 44% with the addition of medical management. The progression-free rate was 96% at 10 years. Of the 20 deaths, three patients died with uncontrolled pituitary adenoma and three died of treatment complications. The actuarial 10-year overall and cause-specific survival rates were 86% and 97%. The actuarial rates of radiation-induced hypopituitarism were 35%, 22% and 22% at 10 years for thyroid, glucocorticoid and gonadal functions, respectively. None of the factors examined were found to be significant predictors of tumor control.

CONCLUSIONS

Post-operative external beam RT is highly effective in preventing recurrence of space-occupying effects of hormonally-active pituitary adenomas. However, long-term biochemical remission is observed only in approximately 40% of patients (at 10 years), with an additional 20% requiring medical therapy. Malignancies of the CNS can develop as an infrequent late event.

Continuous versus intermittent subcutaneous infusion of octreotide in the treatment of acromegaly

This review evaluates the efficacy, tolerability, and safety of continuous subcutaneous infusion (CSI) relative to intermittent subcutaneous injection (ISI) of the somatostatin analog, octreotide in the treatment of acromegaly. Data was extracted from five clinical series using CSI octreotide in acromegaly, six reports comparing CSI to ISI, and three studies comparing pulsatile subcutaneous infusion (PSI) to ISI. Effects of each drug regimen on the control of growth hormone (GH), insulin-like growth factor (IGF-1), clinical symptomatology, pituitary tumor size, and adverse effects were evaluated. Normalization of serum GH or IGF-1 levels, as well as improvement in clinical symptoms was reported in the majority of the patients studied. Cases in which pituitary adenomas decreased in size were also documented during the study period. When the effects of CSI were compared with ISI, a more pronounced control of GH and IGF-1 was observed. In addition, diurnal GH fluctuation during CSI was significantly reduced relative to ISI in two reports. Moreover, in two patients, CSI achieved similar clinical and biochemical effects at lower doses than when the drug was given by ISI. Finally, adverse effects with CSI may be less severe than with ISI. Continuous subcutaneous infusion of octreotide produced biochemical improvement in 67 of the 88 patients reviewed. When compared with ISI, CSI induced more pronounced biochemical control, often with less fluctuation in GH and IGF-1 levels. Because of a lack of data, definite conclusions regarding the differences between regimens on clinical symptomatology and tolerability could not be discerned. A large prospective, long-term randomized crossover study is recommended to make these determinations.